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“Ballistic Six" upper-extremity plyometric training for the pediatric volleyball players. J Strength Cond Res 33(5): 1305- 1310, 2019-The Ballistic Six exercise program includes commonly used upper-body exercises, and the program is recommended for overhead throwing athletes. The purpose of the current study was to investigate the effects of a 12-week the Ballistic Six upper-extremity plyometric training program on upper-body explosive power, endurance, and reaction time in pediatric overhead athletes. Twenty-eight female pediatric volleyball players participated in the study. The participants were randomly divided into 2 study groups: an intervention group (upper-extremity plyometric training in addition to the volleyball training; n = 14) and a control group (the volleyball training only; n = 14). All the participants were assessed before and after a 12-week training program for upper-body power, strength and endurance, and reaction time. Statistical comparison was performed using an analysis of variance test. Comparisons showed that after a 12-week training program, the Ballistic Six upper-body plyometric training program resulted in more improvements in an overhead medicine ball throwing distance and a push-up performance, as well as greater improvements in the reaction time in the nonthrowing arm when compared with control training. In addition, a 1 2-week training program was found to be effective in achieving improvements in the reaction time in the throwing arm for both groups similarly. Compared with regular training, upper-body plyometric training resulted in additional improvements in upper-body power and strength and endurance among pediatric volleyball players. The findings of the study provide a basis for developing training protocols for pediatric volleyball players. [ABSTRACT FROM AUTHOR]

Reduction of physiological strain under a hot and humid environment by a hybrid cooling vest. J Strength Cond Res 33(5): 1429-1436, 2019-Cooling treatment is regarded as one of good practices to provide safe training conditions to athletic trainers in the hot environment. The present study aimed to investigate whether wearing a commercial lightweight and portable hybrid cooling vest that combines air ventilation fans with frozen gel packs was an effective means to reduce participants' body heat strain. In this within-subject repeated measures study, 10 male volunteers participated in 2 heatstress trials (one with the cooling vest-COOL condition, and another without-CON condition, in a randomized order) inside a climatic chamber with a controlled ambient temperature 33° C and relative humidity (RH) 75% on an experimental day. Each trial included a progressively incremental running test, followed by a 40-minute postexercise recovery. Core temperature (Tc), heart rate (HR), sweat rate (SR), rating of perceived exertion (RPE), exercise duration, running distance, and power output were measured. When comparing the 2 conditions, a nonstatistically significant moderate cooling effect in rate of increase in Tc (0.03 ± 0.02° C m ir r 1 for COOL vs. 0.04 ± 0.02° C -m ir r1 for CON, p = 0.054, d = 0.57), HR (3 ± 1 b-min~1 -miru1 for COOL vs. 4 ± 1 b min-1 -m ir r1 for CON, p = 0.229, d = 0.40), and physiological strain index (PSI) (0.20 ± 0.06 unit-min-1 for COOL vs. 0.23 ± 0.06 unit-min-1 for CON, p = 0.072, d = 0.50) was found in the COOL condition during exercise. A nonstatistically significant (p > 0.05) trivial cooling effect {d < 0.2) was observed between the COOL and CON conditions for measures of exercise duration, running distance, power output, SR, and RPE. It is concluded that the use of the hybrid cooling vest achieved a moderate cooling effect in lowering the rate of increase in physiological strain without impeding the performance of progressively incremental exercise in the heat. [ABSTRACT FROM AUTHOR]

resistance is based on the perceived exertion of the exercise or completion of targeted repetitions; exact resistance is typically unknown. The objective of this study was to determine whether knowledge of load during elastic resistance exercise will increase strength gains during exercises. Participants were randomized into 2 strength training groups, elastic resistance only and elastic resistance using a load cell (LC) that displays force during exercise. The LC group used a Smart Handle (Patterson Medical Supply, Chicago, IL, USA) to complete all exercises. Each participant completed the same exercises 3 times weekly for 8 weeks. The LC group was provided with a set load for exercises, whereas the elastic resistance only group was not. The participant's strength was tested at baseline and program completion, measuring isometric strength for shoulder abduction (SAb), shoulder external rotation (SER), hip abduction (HAb), and hip extension (HEx). Independent t-tests were used to compare the normalized torques between groups. No significant differences were found between groups. Shoulder strength gains did not differ between groups (SAb p > 0.05; SER p > 0.05). Hip strength gains did not differ between groups (HAb p > 0.05; HEx p > 0.05). Both groups increased strength because of individual supervision, constantly evaluating degree of difficulty associated with exercise and providing feedback while using elastic resistance. Using an LC is as effective as supervised training and could provide value in a clinical setting when patients are working unsupervised. [ABSTRACT FROM AUTHOR]

Res 33(3): 793-800, 2019-The longitudinal tracking of performance indicators is lacking during the training of young female soccer players. Therefore, changes in 5-m acceleration, 20-m speed, change-of-direction (COD) speed, and repeated-sprint ability (RSA) were quantified during a 3-year period in an English Football Association Center of Excellence. Fourteen players (mean age = 12.1 years, SD = ±0.9) were recruited, and their best performance scores from preseason and in-season testing were averaged. Players were typically exposed to soccer (2 x 90 minutes per week) and strength and conditioning training (1 x 70 minutes per week) and played 20 soccer matches (50-80 minutes) during 35-week seasons. Mean (±90% confidence limits (CL)) overall improvements over the 3 years were 5.9% (1.3) (most likely large) for speed, 4.0% (1.0) (most likely large) for RSA, 8.8% (1.1) for acceleration, and 8.3% (1.4) for COD speed (both most likely very large). Improvements between years one and 2 ranged from most likely moderate to very large. Further small improvements in COD speed and 20-m speed (both likely) were observed between years 2 and 3. Individual differences in response were apparent only for COD speed, which were moderate and small between years 2 and 3. Most likely very large to near-perfect within-player correlations were observed between maturation and sprint measures. These data from a single-arm longitudinal study indicate that systematic exposure to training, which includes one dedicated strength and conditioning session each week, is associated with improvements in sprint-related physical qualities in girls. [ABSTRACT FROM AUTHOR]

Malone, S, Hughes, B, and Collins, K. Effect of training load distribution on aerobic fitness measures in hurling players. J Strength Cond Res 33(3): 825-830, 2019-The aim of the current investigation was to quantify the training intensity distribution of hurling players and their association with changes in aerobic fitness measures within hurling players. Thirty hurling players (n = 30; age 26.5 ± 3.2 years; height 178.9 ± 3.2 cm; body mass 81.5 ± 4.5 kg) were observed during the prechampionship training period (12 weeks). Aerobic fitness measures (...o2max), peak treadmill velocity (km⋅h-1), heart rates (HRs) at 2 and 4 mmol⋅L-1 blood lactate concentrations, and Yo-Yo intermittent recovery test performance (Yo-YolR1) were assessed before and after the training period. Training intensities were categorized using 3 individualized HR zones based on the following criteria: low intensity (≤HR 2 mmol⋅L-1), moderate intensity (between HR 2 and 4 mmol≤L-1), and high intensity (≤HR 4 mmol⋅L-1). Analysis of 1,025 individual training sessions showed that players spent 58.1 ± 2.5%, 24.3 ± 2.9%, and 17.6 ± 1.3% of time in the low-, moderate-, and high-intensity zones, respectively. The training time spent at high intensity (Zone 3) showed moderate-to-large associations with improvements in S2 (r = 0.80; p = 0.04) and S4 (r = 0.58; p = 0.03). Similar trends were observed for time spent in high intensity and improvements in Vo2max (r= 0.77; p = 0.001) and Y0-Y0IRI performance (r= 0.65; p = 0.05). Hurling players have been shown to spend the majority of training time in low (≤ HR 2 mmol⋅L-1) to moderate intensity (between HR 2 and 4 mmol⋅L-1) training. However, only the time spent at high intensity (≤90% of maximal HR) was related to changes in aerobic fitness. These results support the usefulness of the quantification of aerobic training load using HR. The study also supports the efficacy of spending elements of training time within the high-intensity zone to increase hurling player's aerobic fitness characteristics. [ABSTRACT FROM AUTHOR]

Garcia-Hermoso, A, Correa-Bautista, JE, Izquierdo, M, Tordecilla-Sanders, A, Prieto-Benavides, D, Sandoval-Cuellar, C, Gonzalez-Ruiz, K, and Ramirez-Velez, R. Ideal cardiovascular health, handgrip strength, and muscle mass among college students: the FUPRECOL Adults study. J Strength Cond Res 33(3): 747-754, 2019-The American Heart Association established the 2020 Strategic Impact Goals to define the concept of ideal cardiovascular health (CVH) and the metrics needed to monitor it across populations. The purpose of this study was to investigate the relationship between handgrip strength, muscle mass, and ideal CVH among Colombian college students. Data from 1,835 college students were analyzed (1,128 female). Muscular strength was estimated using a hand-held dynamometer and normalized to body mass (normalized grip strength [NGS]). The percentage of body fat was determined for bioelectrical impedance analysis using tetrapo- lar whole-body impedance. Ideal CVH was defined as meeting the ideal levels of 4 behaviors (smoking, body mass index, physical activity, and diet adherence) and 3 factors (total cholesterol, fasting glucose, and blood pressure). Higher levels of NGS and muscle mass (relative to body mass) were associated with a higher number of ideal CVH metrics in both sexes (p for trend <0.001). For the total ideal CVH metrics scored on a continuous scale from 0 (all 7 poor) to 7 (ail 7 ideal), a 1- metric increase was associated with reduced odds of weak NGS (33 and 36%) and low-medium muscle mass (28 and 34%) mass in men and women, respectively (all p < 0.001). This study indicates that in Colombian college students, both handgrip strength and muscle mass are positively associated with the ideal CVH metrics. To reduce the possible future public health burden of muscular weakness, health professionals need to encourage the public to optimize lifestyle-related risk factors during the young adult stage. [ABSTRACT FROM AUTHOR]

Winwood, PW and Buckley, JJ. Short-term effects of resistance training modalities on performance measures in male adolescents. J Strength Cond Res 33(3): 641-650, 2019- This study compared the effects of 7 weeks of bodyweight, mobility, and resistance training programs on strength, power, and sprint times. Thirty-nine male adolescents (aged 14-15 years) were randomly assigned to 1 of 2 groups: bodyweight and mobility training (BMT) (n = 25) or combined bodyweight, mobility, and free-weights training (CBT) (n = 14). A physical education class (n = 23) of similar age constituted a control group (CON). Both training groups performed 2 BMT sessions per week, and the CBT group performed 2 additional free- weight resistance exercise training sessions. Pretesting and posttesting consisted of vertical and horizontal jump tests, 5- and 20-m sprint tests, 2-kg medicine ball throw test, and maximal number of press ups. Small significant improvements (p ≤ 0.01) between pre-post measures were observed in the CBT group for 20 m (12.4%; effect size [ES] = -0.45) sprint time and horizontal jump distance (↑4.2%; ES = 0.43). No significant differences existed between the groups when the mean changes were compared. Effect sizes demonstrated training improvements were in favor of the CBT group (for sprint times, horizontal jump distance, and maximal press ups; ES = 0.35 to -1.35) compared with the BMT and CON groups and in favor of the BMT group (for sprint times and horizontal jump distance; ES = -0.33 to 0.34) compared with the CON group. Seven weeks of BMT and CBT can be beneficial for the development of physical performance capacities in untrained male adolescents. Increased training frequency with the addition of free weights provided the greatest training effects [ABSTRACT FROM AUTHOR]

High-intensity interval training (HIIT)- related neuromuscular adaptations, changes in force production, and on-ice performance were investigated in female ice-hockey players during preseason. Fourteen Finnish championship level ice-hockey players (average age 22 ± 3 years) participated in 2 1/2-week HIIT. Both spinal (H-reflex) and supraspinal (V-wave) neuromuscular responses of the soleus muscle were recorded before and after the training period. Static jump (SJ) and countermove¬ment jump heights, plantarflexor maximum voluntary contraction (MVC), and rate of force development (RFD) were measured. In addition, soleus and tibialis anterior muscle activations (electromyography) were measured during MVC and RFD tests. During on-ice training, skating speed and acceleration tests were performed. Subjects significantly improved their plantarflexion MVC force (11.6 ± 11.2%, p < 0.001), RFD (15.2 ± 15.9%, p < 0.01), and SJ (4.8 ± 7.6%, p ≤ 0.05). Voluntary motor drive to the soleus muscle (V-wave amplitude) increased by 16.0 ± 15.4% (p < 0.01), and coactivation of the tibialis anterior muscle during the plantarflexion RFD test was reduced by -18.9 ± 22.2% (p < 0.05). No change was observed in spinal a-motoneuron excitability (H-reflex) during MVC or in on-ice performance. These results indicate that HIIT can be used to improve athletes' capability to produce maximal and explosive forces, likely through enhanced voluntary activation of their muscles and reduced antagonist coactivation. Therefore, HIIT can be recommended in preseason training to improve neuromuscular performance. However, a longer than 2 1/2-week HIIT period is needed to improve on-ice performance in female ice-hockey players. [ABSTRACT FROM AUTHOR]

Previously, perceived exertion in submaximal resistance exercise protocols was reported to be affected by the intensity of load followed by work-to-rest ratio. Nevertheless, the effect of set configuration, which entails the metabolic, hormonal, and neuromuscular implication of the session, is currently unknown, despite the fact that perceived exertion discriminates these differences. We aimed to analyze the effect of 3 submaximal set configurations on perceived exertion and their relationship with velocity as a mechanical measure of fatigue. Seventeen healthy subjects (23 ± 2 years) performed with the 10-repetition maximum load on the leg press (211 ±45 kg) a total of 40 repetitions with 720 seconds of rest in 3 randomized experimental sessions with the same work-to-rest ratio. The sessions consisted of an interrepetition rest design performing individual repetitions, a cluster design performing groups of 4 repetitions, and a traditional design performing groups of 8 repetitions. At the end of the session, the nonparametric analysis of variance-type test revealed differences between protocols (p < 0.001), with lower values of perceived exertion in the interrepetition rest design in comparison with the cluster design (p = 0.003) and traditional design (p < 0.001). In addition, Spearman's rank correlations (p < 0.001) were observed for the interrepetition rest design (rho = -0.72) and traditional design (rho = -0.8) between perceived exertion and velocity. Our findings suggest that the submaximal set configuration is a determinant of perceived exertion by itself, and that perceived exertion represents similar mechanisms as velocity, such as fatigue and certain characteristics of the session and the individual. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the effect of 2 sessions of resistance exercise (RE) with different volumes on postexercise hypotension (PEH), forearm blood flow (FBF), and cardiac autonomic balance (LF/HF) in hypertensive elderly woman. The study was conducted with 16 hypertensive elderly (25.7 ± 3 kg⋅m-, 55.5 ± 3 years) subjected to 3 experimental sessions, i.e., a control session, exercise with a set (S1), and exercise with 3 sets (S3). For each session, the subjects were evaluated before and after intervention. In the preintervention period, blood pressure (BP), FBF, and LF/HF were measured after 10 minutes of rest in the supine position. Thereafter, the subjects were taken to the gym to perform their exercise sessions or remained at rest during the same period. Both S1 and S3 comprised a set of ten repetitions of 10 exercises, with an interval of 90 seconds between exercises. Subsequently, the measurements were again performed at 10, 30, 50, 70, and 90 minutes of recovery (postintervention) in the supine position. Postexercise hypotension (systolic/diastolic) was greater in S3 than in S1 (-26 ± 4/-14 ± 5 mm Hg vs. -18 ± 5/-8 ± 5 mm Hg, p ≤ 0.05). Similarly, FBF and cardiac LF/HF increased in both sessions, being more evident in S3 than in S1 (4.98 ± 0.32 vs. 4.36 ± 0.27 ml⋅min-1⋅100 ml-1, p ≤ 0.05; and LF/HF = 1.69 ± 0.225 vs. 1.37 ± 0.13 p ≤ 0.05, respectively). We conclude that a single RE session with 3 series were able to promote higher PEH in hypertensive women, and this phenomenon was accompanied by increased FBF and increased cardiac autonomic activity. [ABSTRACT FROM AUTHOR]

The current study examined the impact of different exercise-to-rest ratios on hurling-specific small-sided games (SSG). Thirty-four (n = 34) hurling players were monitored during an in-season training period. Heart rate (Polar Electro Oy, Kempele, Finland) and global positioning system technology (4-Hz; VX Sport, Lower Hutt, New Zealand) were used to analyze the physical and physiological differences between exercise-to-rest ratios across bouts of SSG. Total distance (m), high-speed distance (m) (≥17 km⋅h-1), very high-speed distance (≥22 km⋅h-1) (m), total accelerations (n), acceleration distance (m), peak velocity (km⋅h-1), and % maximum heart rate (%HRmax) were measured. Exercise-to-rest ratios of 2:1 (d = 0.65 ± 0.12; moderate), and 1:1 (d = 0.43 ± 0.12; small), resulted in significant reductions in high-speed distance, very high-speed distance, and acceleration distance. Exercise-to-rest ratios of 1:2 (d = 0.63 ± 0.21; moderate), and 1:3 (d = 1.23 ± 0.22; large), resulted in increased high-speed distance, very high-speed distance, and acceleration distance, but only after the third bout. The first bout of SSG resulted in the lowest %HRmax when compared with all other bouts (d = 0.63 ± 0.22; moderate). A significant bout-to-bout increase in %HRmax independent of exercise-to-rest ratio (d = 0.25 ± 0.04; small) was observed. Exercise-to-rest ratios of 2:1 (d = 0.65 ± 0.14; moderate), and 1:1 (d = 0.65 ± 0.24; moderate), resulted in significantly higher %HRmax during all SSG bouts; however, exercise-to-rest ratios of 1:2 (d = 0.25 ± 0.04; small), and 1:3 (d = 0.15 ± 0.04; trivial), resulted in lower %HRmax during SSG. Coaches should be aware that reducing the rest between bouts of SSGs (2:1 and 1:1 exercise-to-rest ratios) increases the physiological response (%HRmax) with reduced high-speed running performances. Coaches now have data to allow them tp best prepare for session needs with regard to specific SSG exercise-to-rest ratios. [ABSTRACT FROM AUTHOR]

Perrotta, AS, White, MD, Koehle, MS, Taunton, JE, and Warburton, DER. Efficacy of hot yoga as a heat stress technique for enhancing plasma volume and cardiovascular performance in elite female field hockey players. J Strength Cond Res 32(10): 2878–2887, 2018—This investigation examined the efficacy of hot yoga as an alternative heat stress technique for enhancing plasma volume percentage (PV%) and cardiovascular performance. Ten international caliber female field hockey players completed six 60-minute hot yoga sessions using permissive dehydration over 6 days, followed by a 6-day national team camp. Changes in PV% were examined throughout the intervention and postintervention period. A graded maximal exercise test was performed in a thermoneutral environment (23.2 ± 1.0° C) 24 hours before and 24 hours after intervention. Six days of hot yoga initiated a moderate state of hypovolemia (PV% = −3.5%, 90% confidence limit [CL] [−6.9 to −0.13]), trivial improvements in maximal aerobic power (V̇ o 2max) (effect size [ES] = 0.06, 90% CL [−0.16 to 0.28]), and run time to exhaustion (ES = 0.11, 90% CL [−0.07 to 0.29]). Small meaningful improvements were observed in running speed (km·h−1) at ventilatory threshold (VT1) (ES = 0.34, 90% CL [−0.08 to 0.76]), VT2 (ES = 0.53, 90% CL [−0.05 to 1.1]), along with adaptations in the respiratory exchange ratio during high-intensity exercise (ES = –0.25, 90% CL [–0.62 to 0.12]). A large plasma volume expansion transpired 72 hours after intervention (PV% = 5.0%, 90% CL [1.3–8.7]) that contracted to a small expansion after 6 days (PV% = 1.6%, 90% CL [−1.0 to 4.2]). This investigation provides practitioners an alternative heat stress technique conducive for team sport, involving minimal exercise stress that can preserve maximal cardiovascular performance over periodized rest weeks within the yearly training plan. Furthermore, improvements in submaximal performance and a delayed hypervolemic response may provide a performance-enhancing effect when entering a 6-day competition period. [ABSTRACT FROM AUTHOR]

Korak, JA, Paquette, MR, Fuller, DK, Caputo, JL, and Coons, JM. Muscle activation patterns of lower-body musculature among 3 traditional lower-body exercises in trained women. J Strength Cond Res 32(10): 2770–2775, 2018—The deadlift and back and front squats are common multijoint, lower-body resistance exercises that target similar musculature. To our knowledge, muscle activity measured using surface electromyography has never been analyzed among these 3 exercises. Furthermore, most literature examining this topic has included male participants creating a void in the literature for the female population. Knowledge of lower-body muscle activation among these 3 exercises can aid coaches, trainers, and therapists for training and rehabilitative purposes. Trained women (n = 13) completed 2 days of testing including a 1-repetition maximum (1RM) estimation, an actual 1RM, and 3 repetitions at 75% 1RM load for the deadlift and back and front squats. Muscle activity of the 3 repetitions of each muscle was averaged and normalized as a percentage to the 1RM lifts for the deadlift and front and back squats. Five separate repeated-measure analysis of variances were performed indicating muscle activity of the gluteus maximus (GM) differed among the 3 exercises (p = 0.01, = 0.39). Specifically, post hoc analysis indicated greater muscle activity during the front squat (M = 94%, SD = 15%) compared with the deadlift (M = 72%, SD = 16%; p ≤ 0.05) in the GM. No significant differences were observed among the lifts in the vastus medialis, vastus lateralis, biceps femoris, and rectus femoris. Strength and conditioning specialist and trainers can use these findings by prescribing the front squat to recruit greater motor units of the GM. [ABSTRACT FROM AUTHOR]

Crowley, E, Harrison, AJ, and Lyons, M. Dry-land resistance training practices of elite swimming strength and conditioning coaches. J Strength Cond Res 32(9): 2592–2600, 2018—No research to date has investigated dry-land resistance (RT) training practices of elite swimming strength and conditioning coaches. This is the first comprehensive study exploring dry-land RT training practices in swimming. The aims of this study were to examine (a) the dry-land RT training practices and exercises used by elite swimming strength and conditioning coaches and (b) the rationale provided by coaches about their practices and prescription of specific dry-land RT training exercises. Twenty-three (n = 21 males, n = 2 females) elite swimming strength and conditioning coaches, from Ireland (n = 7), Great Britain (n = 5), Australia (n = 6), and the United States of America (n = 5) were recruited through their specific national governing bodies. Coaches completed an online questionnaire consisting of 7 sections; subject information, informed consent, coach's biography, coach education, current training commitments, dry-land RT training practices and exercises, and additional information. The results showed that coaches had varying levels of experience, education and worked with different level swimmers. A total of 95 dry-land RT training exercises were used by the coaches across 4 different dry-land RT training practices (warm-up, circuit training, traditional RT training and plyometrics). Traditional RT training (87%) was the most commonly practiced. The pull-up and squat were the most popular dry-land RT training exercises used by elite swimming strength and conditioning coaches. Future research needs to focus on exploring the specificity and the transfer of RT training exercises to swimming performance. [ABSTRACT FROM AUTHOR]

Lima, C, Li, Y, Low, JL, Herat, N, and Behm, DG. Superior training-specific adaptations with an 8-week yoak push-up training program. J Strength Cond Res 32(9): 2409–2418, 2018—There are few progressive metastability training programs in the literature. The purpose of this study was to investigate changes in strength, endurance, muscle activation, and neuromuscular efficiency after an 8-week progressive, push-up training program under stable and unstable conditions. Nineteen male and female recreationally trained participants performed twice per week, an 8-week push-up training program, using either a relatively unstable suspension system (Yoak) or under stable conditions. Participants were tested in 2 separate sessions before and after training for chest press maximal voluntary isometric contraction (MVIC) forces, and unstable and stable push-up endurance. Participants were tested during all testing measures for anterior deltoid, biceps brachii (BB), triceps brachii (TB), and serratus anterior (SA) electromyography (EMG) activity. The training progression consisted of altering the suspension configurations, push-up height, and increasing the number of sets (1–3 sets). The stable group performed 153.3 and 33.8% less repetitions than the Yoak group when performing push-ups on the Yoak device or stable floor, respectively (p = 0.03). Training-induced MVIC forces were 9.2% (p = 0.03) greater for the Yoak vs. the stable group. Regarding neuromuscular efficiency, the Yoak group decreased (30.4%; p = 0.01) and stable group increased (97.8%; p = 0.02) antagonist BB EMG activity from pre- to post-training. Both groups decreased the TB fatigue index from pre- to post-training. Nevertheless, Yoak group demonstrated 12.5% (p = 0.09) and 8.9% (p = 0.02) lower fatigue indexes with TB and SA, respectively, than the stable group. These findings suggest that Yoak training demonstrates superior improvements over stable training for push-up endurance, neuromuscular efficiency, MVIC, and fatigue index. [ABSTRACT FROM AUTHOR]

Bilateral muscular imbalance can increase the risk of injury and negatively impact on sporting performance. Bilateral muscular imbalances are typically calculated as ([side 1 -- side 2]/reference value) x 100, to provide a percentage value of the difference between limbs. Using different numerator (right-left or strong-weak) or reference values (left, right, strong, weak, average of the 2) could mask or inflate the true difference value. This study aimed to compare the bilateral muscular imbalance ratio calculations, using the absolute difference between limbs as the numerator and the 5 different options as reference values. Twenty-three males (21.6 ± 1.9 years, 1.80 ± 0.06 m, 80.5 ± 13.8 kg) and 11 females (20.8 ± 1.5 years, 1.62 ± 0.03 m, 68.0 ± 6.5 kg) performed the one-legged 6-m timed test and the one-legged triple-hop distance test. The 5 possible combinations were compared with a 2 (sex) x 2 (functional test) x 5 (calculation method) analysis of variance for each test. Significant differences (p ≤ 0.05) were found between sex when the right leg was used as the reference value (men: 6.1%, women: 9.1%), and within calculation methods for men (range: 5.9-6.5%) and women (range: 8.4-9.4%), with low effect sizes (range: 0.07-0.26). These findings demonstrate that using a different reference value for calculating bilateral muscular imbalances does not result in a practically significant difference. These findings can be used to inform a more standardized calculation method which will afford conditioning coaches a more correct evaluation and monitoring of training and rehabilitation programs. [ABSTRACT FROM AUTHOR]

Ward, PA, Ramsden, S, Coutts, AJ, Hulton, AT, and Drust, B. Positional differences in running and nonrunning activities during elite American football training. J Strength Cond Res XX(X): 000–000, 2017—The aim of this investigation was to describe differences in training loads between position groups within professional American football. Integrated micro technology data were collected on 63 NFL football players during an American football training camp. Five key metrics (total distance, high-speed distance, player load (PL), PL per minute, and total inertial movement analysis [IMA]) served to quantify both running and nonrunning activities. Players were classified into position groups (defensive back [DB], defensive linemen [DL], linebacker, offensive linemen [OL], quarterback, running back, tight end, and wide receiver [WR]). Training sessions were identified by their relationship to the upcoming match (e.g., -4, -3, and -2). Running and nonrunning activities varied between position groups relative to the training day. Differences in total distance between DB and WR were observed to be unclear across the 3 training days (game day [GD] -4: 74 ± 392 m; GD -3: −122 ± 348 m; and GD -2: −222 ± 371 m). However, moderate to large differences were observed between these 2 positions and the other positional groups. A similar relationship was observed in PL and PL per minute, with the DB and WR groups performing greater amounts of load compared with other positional groups. Differences in high-speed distance varied across positional groups, indicating different outputs based on ergonomic demands. The OL and DL groups ran less but engaged in a higher amount of nonrunning activities (total IMA) with differences ranging from moderate to large across the 3 training days. Total IMA differences between offensive and defensive linemen were unclear on GD -4 (−4 ± 9) and GD -2 (−2 ± 8) and likely moderate on GD -3 (−9 ± 9). Positional differences with regard to running and nonrunning activities highlight the existence of position-specific training within a training microcycle. In addition, total IMA provides a useful metric for quantifying sport-specific movements within the game of American football. [ABSTRACT FROM AUTHOR]

Moeskops, S, Oliver, JL, Read, PJ, Cronin, JB, Myer, GD, Haff, GG, and Lloyd, RS. Within- and between-session reliability of the isometric midthigh pull in young female athletes. J Strength Cond Res 32(7): 1892–1901, 2018—To investigate the within- and between-session reliability of the isometric midthigh pull (IMTP) in pre– and post–peak height velocity (PHV) female athletes. Nineteen pre- and 19 post-PHV athletes performed bilateral IMTPs using a custom-designed isometric testing system. Participants attended 3 separate testing sessions and performed 3 trials within each session. Peak force, relative peak force, force at 30, 50, 90, 100, 150, 200, and 250 ms, rate of force development (RFD) within time-specific bands, time to peak force (TPF), and time to peak RFD were obtained for analysis. Within- and between-session reliability for each variable was calculated from repeated-measures analysis of variance, intraclass correlation coefficients (ICCs), and coefficients of variation (CV) with 95% confidence intervals. Within- and between-session measures of absolute and relative peak force were found to be reliable for both pre-PHV (CV ≤ 9.4%, ICC ≥ 0.87) and post-PHV (CV ≤ 7.3%, ICC ≥ 0.92), but systematic bias was evident between sessions in the pre-PHV group, from session 1 to 2. Analyses of force at the specific time points revealed CVs between 19–37% and 5–24% for pre-PHV and post-PHV athletes, respectively. Greater variability was evident in TPF, and all RFD-related variables for pre-PHV (CV ≥ 38%) and post-PHV (CV ≥ 27%) athletes, respectively. The IMTP appears a reliable and safe method for evaluating peak force in young female athletes. Overall, post-PHV athletes were more reliable than pre-PHV athletes, with pre-PHV athletes needing additional familiarization to minimize the influence of systematic bias. [ABSTRACT FROM AUTHOR]

This study aimed to analyze the influence of muscular performance parameters on spatiotemporal gait characteristics during running when gradually increasing speed. Fifty-one recreationally trained male endurance runners (age, 28 ± 8 years) voluntarily participated in this study. Subjects performed a battery of jumping tests (squat jump, countermovement jump, and 20-cm drop jump), and after that, the subjects performed an incremental running test (10-20 km⋅h-1) on a motorized treadmill. Spatiotemporal parameters were measured using the OptoGait system. Cluster k-means analysis grouped subjects according to the jumping test performance, by obtaining a group of good jumpers (n = 19) and a group of bad jumpers (n = 32). With increased running velocity, contact time was shorter and flight time and step length were longer, whereas cadence and stride angle were greater (p < 0.001). No significant differences between groups (p ≤ 0.05) were found at any running speed. The results obtained indicate that increased running velocity produced no differences in spatiotemporal adaptations between those runners with good jumping ability and those with poor jumping ability. Based on that, it seems that muscular performance parameters do not play a key role in spatiotemporal adaptations experienced by recreational endurance runners with increased velocity. However, taken into consideration the well-known relationship between running performance and neuromuscular performance, the authors suggest that muscular performance parameters would be much more determinant in the presence of fatigue (exhausted condition) or in the case of considering other variables such as running economy or kinetic. [ABSTRACT FROM AUTHOR]

Understanding the relationship between upper quarter mobility, dynamic stability, and pitching velocity may be beneficial in elucidating underlying factors that affect pitching performance. The purpose of this study was to investigate upper trunk rotation mobility and upper quarter dynamic stability and their correlation to pitch velocity in NCAA Division I collegiate pitchers. We hypothesized that collegiate pitchers with greater upper trunk rotation mobility and upper extremity dynamic stability would exhibit higher pitching velocity. Trunk rotation and the Upper Quarter Y-Balance Test (YBT-UQ) were measured using standardized protocols. Collegiate pitchers (N = 30) then proceeded to complete their team prescribed dynamic and throwing warm-up followed by a pitching session from regulation distance at 100% effort. Each pitch was recorded for velocity and pitch type, only fastballs were used in analysis. The relationships between trunk rotation and fastball velocity, and YBT-UQ scores and fastball velocity were assessed using a series of 2-tail Pearson's correlations (p < 0.05). Throwing and nonthrowing sides (69.6 ± 9.5°, 70.7 ± 9.4°) had similar trunk rotation mobility. No statistically significant correlation between upper trunk rotation mobility and pitch velocity was found (throwing arm: r = 0.131; p < 0.491; nonthrowing arm: r = 0.135; p < 0.478). There was also no correlation between the YBT-UQ and fastball velocity. In this study of Division I baseball pitchers, we found no relationship between trunk rotational mobility, upper quarter dynamic stability, and pitching velocity. This suggests that increased upper extremity stability and trunk mobility are not directly related to fastball velocity. Understanding factors that associate to velocity may be helpful in predicting pitching performance. [ABSTRACT FROM AUTHOR]

This study examined the effects of resistance training on muscular strength and jump performances in young male swimmers. It was hypothesized that adaptations would be of a lower magnitude in less mature (prepeak height velocity [PHV]) than in more mature (post-PHV) subjects. Fourteen pre-PHV (-1.8 ± 1.0 years) and 8 post-PHV (1.6 ± 0.5 years) swimmers undertook a 30 minutes, twice-weekly resistance training program for 8 weeks. They were compared with matched control groups (pre-PHV: -2.0 ± 1.1, n = 15; post-PHV: 1.2 ± 1.0, n = 7). The effects on lower-body isometric strength (LBS), measured with midthigh pull, and vertical jump (VJ) height in the post-PHV group were large (effect size: 1.3 [0.4 to 2.2]) and small (0.4 [-0.4 to 1.2]), respectively. Effects on LBS and VJ height in the pre-PHV group were moderate (0.8 [0.1 to 1.4]) and trivial (0.2 [-0.5 to 0.8]), respectively. Estimates in the post-PHV control group (LBS: 0.7 [-0.2 to 1.6]; VJ: 0.2 [-0.7 to 1.0]) and the pre-PHV control group (LBS: 0.1 [-0.5 to 0.7]; VJ: -0.3 [-0.9 to 0.3]) may indicate the extent to which maturation could contribute to the performance changes seen in the respective training groups. Lower-body isometric strength and VJ are trainable, but to different magnitudes, in pre- and post-PHV swimmers. After appropriate foundational training to establish technical competency, twice-weekly resistance training sessions of 30 minutes duration, comprising 3 sets of 4 exercises can be effective in pre- and post-PHV youth. [ABSTRACT FROM AUTHOR]

We investigated whether physical fitness and body composition in 8-10-year-old Danish children are associated with sports club participation. The study included 423 schoolchildren, comprising 209 girls and 214 boys, of whom 67 and 74%, respectively, were active in sports clubs. Yo-Yo intermittent recovery level 1 for children (YYIR1C), balance, jump and coordination tests, together with dual-energy X-ray absorptiometry, were used to determine exercise capacity and body composition. Children active in sports clubs had better (p < 0.05) YYIR1C (33%, 767 ± 26 vs. 575 ± 29 m), 20-m sprint (3%, 4.33 ± 0.03 vs. 4.48 ± 0.04 seconds), coordination (6%, 68 ± 1 vs. 72 ± 1 second), and balance test performances (9%, 19.3 ± 0.5 vs. 21.2 ± 0.7 falls·min-1) and lower fat mass index (16%, 3.8 ± 0.1 vs. 4.5 ± 0.2 kg[fat]·m-2) than children not active in sports clubs. Ball game players had better (p < 0.05) YYIR1C (38%, 925 ± 39 vs. 671 ± 28 m), 20-m sprint (4%, 4.25 ± 0.03 vs. 4.42 ± 0.04 seconds), and coordination test performances (5%, 65 ± 1 vs. 69 ± 1 second), along with higher (p < 0.05) lean body mass (5%, 24.00 ± 0.22 vs. 22.83 ± 0.25 kg) and whole-body BMD (2%, 0.90 ± < 0.01 vs. 0.88 ± <0.01 g·cm-2) compared with children active in other sports. The study showed that 8--10-year-old Danish children engaged in sports-club activity, especially ball game players, have better exercise capacity and superior body composition compared with children not active in sports clubs. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine the effect of 3 different resistance training (RT) frequencies (1 strength training session per week [1W], 2 strength training sessions per week [2W], or 1 strength training session every second week [0.5W]) on jump, sprint, and repeated sprint ability (RSA) performances in professional futsal players. Thirty-five futsal players were randomized into 1 of 3 groups, the 1W group (n = 12), 2W group (n = 12), or the 0.5W group (n = 11). The players performed the same RT during 6 weeks, and only training frequency differed between the groups. Within-group analysis showed significant improvements in jump (p ≤ 0.001, effect size [ES] = 0.13-0.35), sprint (p ≤ 0.001, ES = 0.48-0.71), and RSA (p ≤ 0.01, ES = 0.22-0.63) from pretest to posttest in 1W and 2W groups. However, no significant (p > 0.05) pre-post changes were observed for the 0.5W group in any variable. In the between-groups analysis, significant better results were found in jump (p ≤ 0.01), sprint (p ≤ 0.01), and RSA performances (p ≤ 0.01) in the 1W and 2W groups in comparison with 0.5W group. Also, jump (p ≤ 0.05) and 5-m sprint (p ≤ 0.05) performances were significantly better in the 2W group in comparison with 1W group. In conclusion, the current study showed that 6 weeks of RT 1 or 2 times per week in addition to typical futsal training produced significant improvements in jump, sprint, and RSA performances. Additionally, RT once every second week may be sufficient to maintain physical fitness in professional futsal players. This information may be useful for coaches when planning training contents during congested fixture schedules or in periods where the emphasis needs to be put on other qualities and to spend as little time as possible on maintaining or increasing physical performance. [ABSTRACT FROM AUTHOR]

This study assessed if the Functional Movement Screen (FMS) can accurately predict noncontact injury in adult soccer players when normalizing noncontact injury occurrence against match exposure levels. Senior male players (n = 89) from 5 League of Ireland semiprofessional clubs participated in the study (mean age = 23.2 ± 4.4 years; mean height = 179.5 ± 6.6 cm; mean body mass = 77.5 ± 7.8 kg). Participants performed the FMS during preseason, and their injury occurrence rates and match minutes were tracked throughout 1 season. In total, 66 noncontact injuries were recorded. No significant difference was found in FMS composite scores between players receiving noncontact injuries and players not suffering a noncontact injury (p = 0.96). There was no significant difference in exposure-normalized noncontact injury incidence between those scoring 14 or below and those scoring above 14 on the FMS (0.36 vs. 0.29 non-contact injuries per player per 1,000 match minutes). Players scoring 14 or below on the FMS had an odds ratio of 0.63 (p = 0.45; 95% CI = 0.19-2.07) of receiving a noncontact injury. Despite previous research showing links between low FMS composite scores and subsequent injury, these results suggest that the FMS cannot accurately predict a male soccer player's likelihood of receiving a noncontact injury and that a lower FMS composite score does not significantly increase their noncontact injury incidence rate per 1,000 match minutes. Caution should therefore be used when using the FMS as a predictor of noncontact injury, and pain prevalence during the FMS, previous injuries, and training/match exposure levels should also be taken into account. [ABSTRACT FROM AUTHOR]

Several studies have confirmed the efficacy of flywheel paradigm training for improving or benefiting muscle volume and force. A meta-analysis of 13 studies with a total of 18 effect sizes was performed to analyse the role of various factors on the effectiveness of flywheel paradigm training. The following inclusion criteria were employed for the analysis: (a) randomized studies; (b) high validity and reliability instruments; (c) published in a high quality peer-reviewed journal; (d) healthy participants; (e) studies where the eccentric programme were described; and (f) studies where increases in muscle volume and force were measured before and after training. Increases in muscle volume and force were noted through the use of flywheel systems during short periods of training. The increase in muscle mass appears was not influenced by the existence of eccentric overload during the exercise. The increase in force was significantly higher with the existence of eccentric overload during the exercise. The responses identified in this analysis are essential and should be considered by strength and conditioning professionals regarding the most appropriate dose response trends for flywheel paradigm systems to optimize the increase in muscle volume and force. [ABSTRACT FROM AUTHOR]

We examined a novel personal fitness training program that combines personal training principles in a small-group training environment. In a typical training session, exercisers warm-up together but receive individualized training for 50 minutes with 1-5 other adults who range in age, exercise experience, and goals for participation. Study participants were 98 regularly exercising adult members of a fitness studio in the southwestern United States (64 women and 32 men), aged 19-78 years (mean, 46.52 years; SD = 14.15). Average membership time was 2 years (range, 1-75 months; mean, 23.54 months; SD = 20.10). In collaboration with the program directors, we developed a scale to assess satisfaction with key features of this unique training program. Participants completed an online survey in Fall 2015. Hypotheses were tested with a serial mediator model (model 6) using the SPSS PROCESS module. In support of the basic tenets of self-determination theory, satisfaction with small-group, individualized training supported basic psychological needs, which in turn were associated with greater autonomous exercise motivation and life satisfaction. Satisfaction with this unique training method was also associated with greater exercise self-efficacy. Autonomous exercise motivation was associated with both exercise self-efficacy and greater self-reported health and energy. Discussion focuses on why exercise programs that foster a sense of social belonging (in addition to motivation and efficacy) may be helpful for successful adherence to an exercise program. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the perceptual responses to resistance exercise with heavy loads (80% 1 repetition maximum [1RM]), light loads (20% 1RM), or light loads in combination with blood flow restriction (BFR). Despite the use of light loads, it has been suggested that the adoption of BFR resistance exercise may be limited because of increases in delayed onset muscle soreness (DOMS) and perceived exertion. Seventeen healthy untrained males participated in this balanced, randomized cross-over study. After 4 sets of elbow-flexion exercise, participants reported ratings of perceived exertion (RPE), with DOMS also recorded for 7 days after each trial. Delayed onset muscle soreness was significantly greater for low-pressure continuous BFR (until 48 hours postexercise) and high-pressure intermittent BFR (until 72 hours postexercise) than for traditional heavy-load resistance exercise and light-load resistance exercise. In addition, RPE was higher for heavy-load resistance exercise and high-pressure intermittent BFR than for low-pressure continuous BFR, with all trials greater than light-load resistance exercise. For practitioners working with untrained participants, this study provides evidence to suggest that to minimize the perception of effort and postexercise muscle soreness associated with BFR resistance exercise, continuous low-pressure application may be more preferential than intermittent high-pressure application. Importantly, these perceptual responses are relatively short-lived (~2 days) and have previously been shown to subside after a few exercise sessions. Combined with smaller initial training volumes (set x repetitions), this may limit RPE and DOMS to strengthen uptake and adherence and assist in program progression for muscle hypertrophy and gains in strength. [ABSTRACT FROM AUTHOR]

The aims of this study were to examine the movement demands of preseason practice in National Collegiate Athletic Association Division I college football players using portable global positioning system (GPS) technology and to assess perceived wellness associated with preseason practice to determine whether GPS-derived variables from the preceding day influence perceived wellness the following day. Twenty-nine players were monitored using GPS receivers (Catapult Innovations, Melbourne, Australia) during 20 preseason practices. Individual observations (n = 550) were divided into offensive and defensive position groups. Movement variables including low-, medium-, high-intensity, and sprint distance, player load, and acceleration and deceleration distance were assessed. Perceived wellness ratings (n = 469) were examined using a questionnaire which assessed fatigue, soreness, sleep quality, sleep quantity, stress, and mood. A 1-way analysis of variance for positional movement demands and multi-level regressions for wellness measures were used, followed by post hoc testing to evaluate the relational significance between categorical outcomes of perceived wellness scores and movement variables. Results demonstrated significantly (p ≤ 0.05) greater total, high-intensity, and sprint distance, along with greater acceleration and deceleration distances for the defensive back and wide receiver position groups compared with their respective offensive and defensive counterparts. Significant (p ≤ 0.05) differences in movement variables were demonstrated for individuals who responded more or less favorably on each of the 6 factors of perceived wellness. Data from this study provide novel quantification of the position- specific physical demands and perceived wellness associated with college football preseason practice. Results support the use of position-specific training and individual monitoring of college football players. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the efficacy of a novel, 16-week high-intensity cardioresistance training (HICRT) program on measures of aerobic fitness, agility, aerobic power, muscular endurance, lower-body explosive power, and self-reported activity level. The intervention group (N = 129; 63 f, 24.65 ± 5.55 years) had a baseline ...O2max of 39.83 ± 9.13. These individuals participated in 26, 70-minute exercise sessions, and 4 fitness testing sessions. Participants were matched with a nonexercise control group, paired by sex, age, and baseline ...O2max. Matched controls (N = 129, 63 f, 24.26 ± 5.59 years) had a baseline ...O2max of 39.86 ± 8.59 and completed preintervention and postintervention ...O2max testing only. The results demonstrate that participants in the fitness intervention group significantly increased their ...O2max (2.72 ± 0.31, Mdiff ± SE; p < 0.001) and reported being more physically active (0.42 ± 0.11, Mdiff ± SE; p < 0.001) after the intervention. The matched control group showed no significant pre--post intervention changes. Participants in the fitness intervention showed a significant improvement in 3 of 5 components of the fitness field tests. Specifically, significant improvements were observed for the 1-minute rower (5.32 ± 0.505, Mdiff ± SE; p < 0.001), 1-minute push-up (8.168 ± 0.709, Mdiff ± SE; p < 0.001), and 1.5-mile run tests (1.79 ± 0.169, Mdiff ± SE; p < 0.001). No significant improvements were observed for the shuttle run (p = 0.173) or standing long jump (p = 0.137). These findings demonstrate the efficacy of a novel, HICRT intervention across multiple dimensions of fitness for young- and middle-aged adults. High-intensity cardioresistance training affords flexibility for tailoring to meet desired health and fitness outcomes and makes perceivably daunting high-intensity functional training and multimodal sports training more accessible to general, traditionally nonathletic, populations. [ABSTRACT FROM AUTHOR]

Recently, an interest has developed in the potential to rinse the oral cavity with key nutrients to impact various types of exercise and presumably sporting performance. Although multiple studies examining carbohydrate mouth rinsing have been completed, conflicting evidence surrounding caffeine mouth rinsing persists, and no research has explored its ability to impact high-intensity, intermittent running performance. This study investigated the independent and synergistic ability of carbohydrate and caffeine mouth rinsing to improve intermittent running performance. The Yo-Yo Intermittent Recovery Test-Level 1 (Yo-Yo Level 1) was completed in 10 collegiate (National Collegiate Athletic Association [NCAA] Division II) male lacrosse players after a 10-second mouth rinse with a solution of either carbohydrate (CHO), caffeine (CAF), carbohydrate + caffeine (CHO + CAF), placebo (H2O), or a no rinse control (CON). No significant improvements in Yo-Yo IRT-1 performance were found (p > 0.05). Perceptual indications of effort (i.e., rating of their perceived exertion [RPE]) were significantly lower (p ≤ 0.05) in CHO and CHO + CAF when compared with CON after speed level 11. Interestingly, RPE levels were nonsignificantly lower in all but one level of the Yo-Yo Level 1 for CHO in comparison with other groups. Carbohydrate and caffeine mouth rinsing seems to exert no impact on running performance before maximal intermittent running in a group of male collegiate lacrosse players. [ABSTRACT FROM AUTHOR]

Even though dry-land S&C training is a common practice in the context of swimming, there are countless uncertainties over its effects in performance of age group swimmers. The objective was to investigate the effects of dry-land S&C programs in swimming performance of age group swimmers. A total of 21 male competitive swimmers (12.7 ± 0.7 years) were randomly assigned to the Control group (n = 7) and experimental groups GR1 and GR2 (n = 7 for each group). Control group performed a 10-week training period of swim training alone, GR1 followed a 6-week dry-land S&C program based on sets and repetitions plus a 4-week swim training program alone and GR2 followed a 6-week dry-land S&C program focused on explosiveness, plus a 4-week program of swim training alone. Results for the dry-land tests showed a time effect between week 0 and week 6 for vertical jump (p < 0.01) in both experimental groups, and for the GR2 ball throwing (p < 0.01), with moderate to strong effect sizes. The time x group analyses showed that for performance in 50 m, differences were significant, with the GR2 presenting higher improvements than their counterparts (F = 4.156; p = 0.007; ηp² = 0.316) at week 10. Concluding, the results suggest that 6 weeks of a complementary dry-land S&C training may lead to improvements in dry-land strength. Furthermore, a 4-week adaptation period was mandatory to achieve beneficial transfer for aquatic performance. Additional benefits may occur if coaches plan the dry-land S&C training focusing on explosiveness. [ABSTRACT FROM AUTHOR]

Foam rolling has been shown to increase range of motion without subsequent performance impairments of the rolled muscle, however, there are no studies examining rolling effects on antagonist muscles. The objective of this study was to determine whether foam rolling the hamstrings and/or quadriceps would affect hamstrings and quadriceps activation in men and women. Recreationally, active men (n = 10, 25±4.6 years, 180.1±4.4 cm, 86.5±15.7 kg) and women (n = 8, 21.75±3.2 years, 166.4±8.8 cm, 58.9±7.9 kg) had surface electromyographic activity analyzed in the dominant vastus lateralis (VL), vastus medialis (VM), and biceps femoris (BF) muscles on a single leg landing from a hurdle jump under 4 conditions. Conditions included rolling of the hamstrings, quadriceps, both muscle groups, and a control session. Biceps femoris activation significantly decreased after quadriceps foam rolling (F(1,16) = 7.45, p = 0.015, 28.9%). There were no significant changes in quadriceps activation after hamstrings foam rolling. This might be attributed to the significantly greater levels of perceived pain with quadriceps rolling applications (F(1,18) = 39.067, p, 0.001, 98.2%). There were no sex-based changes in activation after foam rolling for VL (F(6,30) = 1.31, p = 0.283), VM (F(6,30) = 1.203, p = 0.332), or BF (F(6,36) = 1.703, p = 0.199). Antagonist muscle activation may be altered after agonist foam rolling, however, it can be suggested that any changes in activation are likely a result of reciprocal inhibition due to increased agonist pain perception. [ABSTRACT FROM AUTHOR]

The purpose of this study was to generate normative values for the standing long jump (SLJ) test in 9- to 17.9-year olds and to investigate sex and age-group differences. The sample comprised 8,034 healthy Colombian schoolchildren [boys n = 3,488 and girls n = 4,546; mean (SD) age 12.8 (±2.3) years old]. Each participant performed two SLJ. Centile smoothed curves, percentile, and tables for the third, 10th, 25th, 50th, 75th, 90th, and 97th percentiles were calculated using Cole's Lambda-Mu-Sigma method. The 2-way analysis of variance tests and Cohen's d showed that the maximum SLJ (centimeter) was higher in boys than in girls across age groups (p, 0.01), reaching the peak at 13 years. Posthoc analyses within the sexes showed yearly increases in SLJ in all ages. In boys, the 50th percentile SLJ score ranged from 109 to 165 cm. In girls, the 50th percentile jump ranged from 96 to 120 cm. For girls, jump scores increased yearly from age 9 to 12.9 years before reaching a plateau at an age between 13 and 15.9. Our results provide, for the first time, sex- and age-specific SLJ reference values for Colombian schoolchildren aged 9-17.9 years. The normative values presented in this study provide the basis for the determination of the proposed age- and sex-specific standards for the FUPRECOL (Association for Muscular Strength with Early Manifestation of Cardiovascular Disease Risk Factors Among Colombian Children and Adolescents) Study-Physical fitness battery for children and adolescents. [ABSTRACT FROM AUTHOR]

Previous research in academy rugby league players has evaluated the development of physical qualities according to chronological age. However, no study has considered the training age, defined as the number of formalized years of strength and conditioning training, of these players. Therefore, the purpose of this study was to present and compare the annual changes in physical qualities of academy rugby league players according to training age. Sixty-one academy players undertook a fitness testing assessment, including anthropometric (height, body mass, sum of 4 skinfolds) and physical (10 and 20 m sprint, 10m momentum, vertical jump, Yo-Yo intermittent recovery test level 1 [Yo-Yo IRTL1], one-repetition maximum [1RM] squat, bench press and prone row) measures at the start of preseason on 2 consecutive annual occasions. Players were categorized into one of 3 training age groups (i.e., 0, 1, or 2 years) and were analyzed using magnitude-based inferences. Almost certain, very likely or likely annual improvements were identified for body mass, 10m momentum, Yo-Yo IRTL1, vertical jump, and all strength measures for the 3 training age groups. When training age groups were compared, 1 year showed possibly or likely lower strength increases than 0 years training age. However, the 2 years training age group demonstrated possibly or likely increased strength changes compared with 1 year. These findings suggest that training age is an important consideration for strength and conditioning practitioners but it is likely to be a combination of chronological age, biological maturity, and training experience alongside dynamic interplayer variability that influences the physical development of academy rugby league players. [ABSTRACT FROM AUTHOR]

This study investigated the reliability and validity of the load--velocity relationship to predict the free-weight back squat one repetition maximum (1RM). Seventeen strength-trained males performed three 1RM assessments on 3 separate days. All repetitions were performed to full depth with maximal concentric effort. Predicted 1RMs were calculated by entering the mean concentric velocity of the 1RM (V1RM) into an individualized linear regression equation, which was derived from the load--velocity relationship of 3 (20, 40, 60% of 1RM), 4 (20, 40, 60, 80% of 1RM), or 5 (20, 40, 60, 80, 90% of 1RM) incremental warm-up sets. The actual 1RM (140.3 ± 27.2 kg) was very stable between 3 trials (ICC = 0.99; SEM = 2.9 kg; CV = 2.1%; ES = 0.11). Predicted 1RM from 5 warm-up sets up to and including 90% of 1RM was the most reliable (ICC = 0.92; SEM = 8.6 kg; CV = 5.7%; ES = -0.02) and valid (r = 0.93; SEE = 10.6 kg; CV = 7.4%; ES = 0.71) of the predicted 1RM methods. However, all predicted 1RMs were significantly different (p ≤ 0.05; ES = 0.71--1.04) from the actual 1RM. Individual variation for the actual 1RM was small between trials ranging from -5.6 to 4.8% compared with the most accurate predictive method up to 90% of 1RM, which was more variable (-5.5 to 27.8%). Importantly, the V1RM (0.24 ± 0.06 m•s-1) was unreliable between trials (ICC = 0.42; SEM = 0.05 m•s-1; CV = 22.5%; ES = 0.14). The load--velocity relationship for the full depth free-weight back squat showed moderate reliability and validity but could not accurately predict 1RM, which was stable between trials. Thus, the load--velocity relationship 1RM prediction method used in this study cannot accurately modify sessional training loads because of large V1RM variability. [ABSTRACT FROM AUTHOR]

This study examines the influence ambient temperature has on the distances covered by players in soccer matches. For this purpose, 1,211 games from the top German professional leagues were analyzed over the course of the seasons 2011/12 and 2012/13 using an optical tracking system. Data show (a) significant differences in the total distance covered (TDC, in meters per 10 minutes) between the 1. Bundesliga (M = 1,225) and 2. Bundesliga (M = 1,201) and (b) a significant decrease in TDC from neutral (-4 to 13° C, M = 1,229) to warm (≥14° C, M = 1,217) environments. The size of the temperature effect is greater in the 1. Bundesliga (d = 0.30 vs. d = 0.16), although these players presumably have a higher level of fitness. This suggests that better players reduce their exertion level to a greater extent, thus preserving their ability to undertake the high-intensity activities when called upon. No reduction in running performance due to cold (≤5° C) temperatures was observed. [ABSTRACT FROM AUTHOR]

The purpose of this study was to review the existing literature investigating carbohydrate mouth rinsing as an ergogenic aid using the effect sizes (ES) and percentage change in performance of the respective studies as outcome measures. A trivial-small average overall ES was present for the 25 studies included in the review (0.18, 95% confidence interval [CI] = 0.10-0.27). Effect sizes for the subgroups were ≥25 minutes (0.25, 95% CI = 0.14-0.36), #180 seconds (0.06, 95% CI = 20.03 to 0.15), resistance exercise (20.09, 95% CI = 20.20 to 0.03) but the ES is still small. A subanalysis of ;1-h cycling time trial performance resulted in an overall ES of 0.20 (95% CI = 0.02-0.38), and ES for performance time and power output of 0.31 (95% CI = 20.02 to 0.64) and 0.19 (95% CI = 20.09 to 0.46), respectively. Although ES were small, the average percentage change in performance in ;1-hour trials was 2.48%, which may have implications for elite performers as this is greater than the 1.30% smallest worthwhile change recommended in the past research. [ABSTRACT FROM AUTHOR]

Musculoskeletal injuries (MSK-Is) are a significant health problem for both military and athletic populations. Research indicates that MSK-I is associated with physical fitness; however, the association between specific components of physical fitness and MSK-I in military and athletic populations has not been systematically examined. Our goal was to systematically review the literature to provide a best evidence synthesis on the relationship between components of physical fitness and MSK-I risk in military and civilian athletic populations. This first of 3 manuscripts focuses on cardiorespiratory endurance (CRE). MEDLINE, EBSCO, EMBASE, and the Defense Technical Information Center were searched for original studies published from 1970 through 2015 that examined associations between physical fitness and MSK-I. Fortynine of 4,229 citations met our inclusion criteria. Primary findings indicate that there is (a) strong evidence that poor performance on a set distance run for time is a predictor for MSK-I risk in both genders; (b) strong evidence that poor performance on timed shuttle runs is a predictor for MSK-I risk in males; (c) moderate evidence in males and limited evidence in females that poor performance on a timed step test is a predictor of MSK-I risk; and (d) limited or insufficient evidence that poor performance on the Cooper run test, maximal and submaximal aerobic graded exercise tests, and the Conconi test are predictors of MSK-I risk in males or females or both. Several measures of CRE are risk factors for training-related MSK-I in military and civilian athletic populations, indicating that CRE may be an important measure for MSK-I risk stratification. [ABSTRACT FROM AUTHOR]

Strength and conditioning (S&C) coaches offer expert guidance to help those they work with achieve their personal fitness goals. However, because of cost and availability issues, individuals are often left training without expert supervision. Recent developments in inertial measurement units (IMUs) and mobile computing platforms have allowed for the possibility of unobtrusive motion tracking systems and the provision of realtime individualized feedback regarding exercise performance. These systems could enable S&C coaches to remotely monitor sessions and help gym users record workouts. One component of these IMU systems is the ability to identify the exercises completed. In this study, IMUs were positioned on the lumbar spine, thighs, and shanks on 82 healthy participants. Participants completed 10 repetitions of the squat, lunge, single-leg squat, deadlift, and tuck jump with acceptable form. Descriptive features were extracted from the IMU signals for each repetition of each exercise, and these were used to train an exercise classifier. The exercises were detected with 99% accuracy when using signals from all 5 IMUs, 99% when using signals from the thigh and lumbar IMUs and 98% with just a single IMU on the shank. These results indicate that a single IMU can accurately distinguish between 5 common multijoint exercises. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine the effect of a neuromuscular dentistry--designed mouthguard (NMDD) on dynamic movement ability. Forty-two competitive athletes (8 women, 21.9 ± 2.9 years, 66.8 ± 18.8 kg, 1.68 ± 0.11 m; 34 men, 22.8 ± 4.8 years, 77.4 ± 12.7 kg, 1.78 ± 0.08 m) with greater than 2 years' experience in their designated sport were enrolled in the study. Participants completed the Functional Movement Screen (FMS), modified Star Excursion Balance Test (mSEBT), and a single-leg landing (SLL) task. Each subject was tested with 3 separate mouthguard conditions in random order: (a) no mouthguard (NO), (b) over-the-counter boil-and-bite mouthguard (BB; Shockdoctor Gravity, (c) and an NMDD (Pure Power Elite). Data were analyzed using a repeated-measures analysis of variance for each variable. There were no differences between mouthguard conditions in each of the 7 individual components or composite FMS score (p > 0.05). No differences were seen in the anterior, posteromedial, or posterolateral movements of the mSEBT; overall composite score; or time-to-contact measurements (p > 0.05). The BB condition (2.16 Nm⋅kg-1) exhibited higher peak knee valgus moments (pKVM) on the right leg only when compared with the NMDD condition (1.95 Nm⋅kg-1; p = 0.003) but not the NO condition (2.09 Nm⋅kg-1; p = 0.7262) during the SLL task. No differences in pKVM were seen on the left leg (p = 0.324). In conclusion, an NMDD was not effective at enhancing or diminishing measures of dynamic movement ability compared with BB or NO conditions. [ABSTRACT FROM AUTHOR]

We investigated whether cold water immersion (CWI) after intensive training sessions can enhance recovery in elite Olympic weightlifters, taking into account each athlete's individual response pattern. The entire German male Olympic weightlifting national team participated in the study (n = 7), ensuring collection of data from elite athletes only. Using a randomized cross-over design, the athletes went through 2 high-intensity training microcycles consisting of 5 training sessions that were either followed by a CWI or passive recovery. Barbell speed in a snatch pull movement, blood parameters, and subjective ratings of general fatigue and recovery were assessed throughout the study. Physical performance at 2 snatch pull intensities (85% one repetition maximum [1RM]: -0.15% vs. -0.22%, p = 0.94; 90% 1RM: -0.7% vs. +1.23%, p = 0.25) did not differ significantly (condition x time). Although questionnaires revealed a significant decline in the ratings of overall recovery (p < 0.001) and a significantly higher rating of overall stress (p = 0.03) over time, no significant differences between conditions (p = 0.14; p = 0.98) could be revealed. Similarly, neither of the analyzed blood parameters changed significantly between conditions over time (creatine kinase: p = 0.53; urea: p = 0.43; cortisol: p = 0.59; testosterone: p = 0.53; testosterone:cortisol ratio: p = 0.69). In general, CWI did not prove to be an effective tool to enhance recovery in elite Olympic weightlifters over a 3-day intensive training period. However, even though the group was rather homogeneous with regard to performance, there were considerable intersubject differences in their response to CWI. It seems that athletes are best advised on a case-by-case basis. [ABSTRACT FROM AUTHOR]

The current study examined how the impact of pitch dimensions influences physiological and running performance during 4-minute small-sided games (SSGs). Twenty-four (n = 24) hurling players were monitored with global positioning system and heart rate monitors during the in-season training period. Total distance (in meters), high-speed running distance (in meters) (≥17 km⋅h-1), very high-speed running distance (≥22 km⋅h-1) (in meters), total accelerations (n), acceleration distance (in meters), and peak and mean velocity (in kilometers per hour) were calculated. Additionally, SSGs rate of perceived exertion (RPESSG; AU), % maximum heart rate, and individualized training impulse (iTRIMP; AU) were collected. The current results show that the manipulation of SSGs pitch size has an impact on the running performance and physiological responses. The data showed that SSGs played on large pitches (SSG80 x 20 m) had greater running demands than medium (SSG60 x 20 m) or small (SSG40 x 20 m) pitches, with significantly more distance covered in all movement categories. Total distance covered at high speed was 354 ± 111 m on a large pitch, 254 ± 72 m on a medium pitch, and 198 ± 62 m on a small pitch. Large pitch dimensions resulted in greater physiological and perceptual demands on players (higher %HRmax, iTRIMP [AU], and RPESSG [AU]) compared with medium and small pitches. The current data help applied practitioners to understand further how modifying different aspects of SSGs can alter the running and physiological responses of players. Moreover, applied practitioners now have consistent information to design and optimize their training time in mixing the physical, technical, and tactical elements within specific SSGs pitch dimensions. [ABSTRACT FROM AUTHOR]

To enhance recovery from sport, cold water immersion (CWI) and contrast water therapy (CWT) have become common practice within high level team sport. Initially, athletes relied solely on anecdotal support. As there has been an increase in the volume of research into recovery including a number of general reviews, an opportunity existed to narrow the focus specifically examining the use of hydrotherapy for recovery in team sport. A Boolean logic [AND] keyword search of databases was conducted: SPORTDiscus; AMED; CINAHL; MEDLINE. Data were extracted and the standardized mean differences were calculated with 95% confidence interval (CI). The analysis of pooled data was conducted using a random-effect model, with heterogeneity assessed using /2. Twenty-three peer reviewed articles (n = 606) met the criteria. Meta-analyses results indicated CWI was beneficial for recovery at 24 hours (countermovement jump: p = 0.05, CI: -0.004 to 0.578; All-out sprint: p = 0.02, -0.056 to 0.801) following team sport. The CWI was beneficial for recovery at 72 hours (fatigue: p = 0.03, CI: 0.061-1.418) and CWT was beneficial for recovery at 48 hours (fatigue: p = 0.04, CI: 0.013-0.942) following team sport. The CWI was beneficial for neuromuscular recovery 24 hours following team sport, whereas CWT was not beneficial for recovery following team sport. In addition, when evaluating accumulated sprinting, CWI was not beneficial for recovery following team sports. In evaluating subjective measures, both CWI (72 hours) and CWT (24 hours) were beneficial for recovery of perceptions of fatigue, following team sport. However neither CWI nor CWT was beneficial for recovery, of perceptions of muscle soreness, following team sport. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare the acute physiological responses within and between resistance training (RT) and high-intensity interval training (HIIT) matched for time and with comparable effort, in a school setting. Seventeen early adolescents (12.9 ± 0.3 years) performed both RT (2-5 repetitions perceived short of failure at the end of each set) and HIIT (90% of age-predicted maximum heart rate), equated for total work set and recovery period durations comprising of 12 "sets" of 30-second work followed by 30-second recovery (total session time 1 2 minutes). Variables of interest included oxygen consumption, set and session heart rate (HR), and rate of perceived exertion, and change in salivary cortisol (SC), salivary alpha amylase, and blood lactate (BL) from presession to postsession. Analyses were conducted to determine responses within and between the 2 different protocols. For both RT and HIIT, there were very large increases pretrial to posttrial for SC and BL, and only BL increased greater in HIIT (9.1 ± 2.6 mmol⋅L-1) than RT (6.8 ± 3.3 mmol⋅L-1). Mean set HR for both RT (170 ± 9.1 b⋅min-1) and HIIT (1 79 ± 5.6 b⋅min-1) was at least 85% of HRmax. ...O2 over all 12 sets was greater for HIIT (33.8 ± 5.21 ml⋅kg-1⋅min-1) than RT (24.9 ± 3.23 ml⋅kg-1⋅min-1). Brief, repetitive, intermittent forays into high but not supramaximal intensity exercise using RT or HIIT seemed to be a potent physiological stimulus in adolescents. [ABSTRACT FROM AUTHOR]

Boxing is one of the most popular striking combat sports in the world. The aim of this review was to present data concerning performance analysis (time-motion and technical-tactical analysis) and physiological responses (i.e., blood lactate concentration [BLC], heart rate, and oxygen consumption) during novice and elite male simulated and official amateur boxing competitions in any age category. The present review shows that boxing competition is a high-intensity intermittent striking combat sport. Typically, the activity-to-rest ratio was higher in elite (18:1) than in novice (9:1) boxers and significant differences were observed between rounds (first round = 16:1, second round = 8:1, and third round = 6:1) in novice boxers. Thus, total stop-time and total stop-frequency increased over subsequent rounds in novice boxers. The technical-tactical aspects in elite and novice boxing bouts were different between rounds and dependent on the match outcome (i.e., winners vs. losers). Particularly, the current review highlights that triple-punch combinations, total combinations, block- and counter-punch combinations, total punches to the head, technical performance effectiveness, and defensive- and offensive-skills effectiveness may have contributed to win in novice and elite boxing competitions. Higher frequencies of technical movements were also observed in elite compared with novice boxers. From a physiological point of view, BLC increased significantly from postround 1 compared with postround 3 in novice boxing match. BLC was also higher in official than in simulated elite boxing matches in senior compared with junior boxers and in medium heavy-weight category compared with light- and medium-weight categories in junior boxing competition. A higher percentage of maximal heart rate (%HRmax) and maximal oxygen uptake (...O2max) were reported in round 3 compared with rounds 2 and 1 in elite boxing competition. In conclusion, these data are useful for both technical-tactical and physical conditioning sessions. Coaches and fitness trainers are encouraged to adjust their training according to these particular characteristics, specifically in terms of age, participants' level, weight categories, and combat contest type. [ABSTRACT FROM AUTHOR]

Subacromial impingement syndrome (SIS) has been reported as an etiological source of shoulder pain among weight-training (WT) participants; however, a paucity of evidence exists to describe intrinsic risk factors. The purpose of this study was to investigate specific risk-related joint and muscle adaptations among WT participants identified as having SIS based on a previously validated clinical testing cluster. Fifty-five men (mean age 27.3 years) who participated in recreational WT a minimum of 2 dw⋅k-1 were recruited, including 24 individuals with SIS and 31 without SIS serving as controls. Active range of motion (AROM), bodyweight-adjusted strength values, and strength ratios were compared between groups. Significant differences were present as WT participants with SIS had decreased internal and external rotation AROM (p ≤ 0.016) and decreased bodyweight-adjusted strength values of the external rotator and lower trapezius musculature (p ≤ 0.02) when compared with WT participants without SIS. Select strength ratios were greater in the SIS group (p ≤ 0.004) implying agonist to antagonist muscle imbalances. The impaired joint and muscle characteristics identified among WT participants with SIS are not without consequence, as they are associated with shoulder disorders in both general and athletic populations. Practical applications for these findings may reside in exercise prescription that addresses internal rotation mobility, mitigates training bias, and favors muscles responsible for stabilization, such as the external rotators and lower trapezius. Strength and conditioning professionals should consider risk-related adaptations associated with WT when prescribing upper-extremity exercises. [ABSTRACT FROM AUTHOR]

The aims of the present study were to generate normative vertical jump height and predicted peak power (Ppeak) data for 9- to 17.9-year-olds and to investigate between-sex and age group differences in these measures. This was a cross-sectional study of 7,614 healthy schoolchildren (boys n = 3,258 and girls n = 4,356, mean [SD] age 12.8 [2.3] years). Each participant performed 2 countermovement jumps; jump height was calculated using a Takei 5414 Jump- DF Digital Vertical (Takei Scientific Instruments Co., Ltd.). The highest jump was used for analysis and in the calculation of predicted Ppeak. Centile smoothed curves, percentiles, and tables for the 3rd, 10th, 25th, 50th, 75th, 90th, and 97th percentiles were calculated using Cole's LMS (L [curve Box-Cox], M [curve median], and S [curve coefficient of variation]) method. The 2-way analysis of variance tests showed that maximum jump height (in centimeters) and predicted Ppeak (in watts) were higher in boys than in girls (p < 0.01). Post hoc analyses within sexes showed yearly increases in jump height and Ppeak in all ages. In boys, the maximum jump height and predicted Ppeak 50th percentile ranged from 24.0 to 38.0 cm and from 845.5 to 3061.6 W, respectively. In girls, the 50th percentile for jump height ranged from 22.3 to 27.0 cm, and the predicted Ppeak was 710.1 2036.4 W. For girls, jump height increased yearly from 9 to 1 7.9 years old. Our results provide, for the first time, sex- and age-specific vertical jump height and predicted Ppeak reference standards for Colombian schoolchildren aged 9-17.9 years. [ABSTRACT FROM AUTHOR]

The use of energy drinks among athletes has risen greatly. Caffeine and taurine are the 2 primary performance enhancing ingredients found in energy drinks. The number of emergency department visits involving energy drinks doubled over the past 5 years. Reviews of the health complications have highlighted adverse cardiovascular events. The literature reveals that caffeine is known to moderately increase blood pressure (BP) and heart rate (HR). The purpose of this study was to determine the effect of 3 different energy drinks on cardiovascular and performance measures. Fifteen recreational runners completed 5 trials. The first trial consisted of a graded exercise protocol. The 4 remaining trials consisted of 15-minute economy trials at a treadmill speed consistent with 70% of subject's ...O2max. An hour before subjects ingested 1 of the 3 energy drinks or a placebo. HR, BP, ...O2, and rating of perceived exertion (RPE) were recorded during the 15-minute trial. Mean values for dependent measures were compared using repeated-measures analysis of variance. Fifteen-minute systolic BP readings were significantly lower in the placebo trials (156.93 ± 15.50) in relation to the 3 energy drink trials (163.87 ± 13.30, 166.47 ± 13.71, and 165.00 ± 15.23). There were no significant differences in diastolic BP and HR. There were no significant differences found in ...O2 or RPE measures. Ingestion of energy drinks demonstrated no change in ...O2 or RPE during the economy trials. The findings show no performance benefits under the conditions of this study. However, there does appear to be a significant increase in systolic BP. [ABSTRACT FROM AUTHOR]