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Purpose: The aim of this study was to examine the short and long-term effects of a simple strength training program on muscle injury prevention in soccer players. Methods: Twenty-seven U-19 elite male soccer players participated in the study. The investigation was conducted over two consecutive and similar seasons (e.g., the same staff, players, weekly training schedule), the first being the control and the second the experimental season. The strength program was carried out 2 times per week, for 10 weeks, during part of the preseason and in-season. Injury incidence and absence days were compared between both seasons, according to the injury rate ratio (IRR), with 95% CI and the Z test. Results: A lower number of total and hamstring injuries were recorded during the experimental (9 and 2, respectively) compared to the control (15 and 7, respectively) period. During the 10 weeks intervention period, the injury rate ratio (IRR) was lower in the experimental season than in the control season (IRR = 8.12; 95% CI: 1.00-66.03; effect size (ES) = 3.30, large). In addition, there was a decline in absence days per injury and in the number of absence days/1000 h (IRR = 2.44; 95% CI: 1.90-3.14; ES = 1.12) during the experimental season. Conclusion: The results of this study suggest that this simple strength-training program could reduce the muscle injury incidence during its application period in young soccer players.

Purpose: Children with autism spectrum disorder (ASD) without intellectual disability (ID) exhibit social and motor impairments and circumscribed interests/behaviors that contribute to lower physical activity (PA) levels. Despite the need for exercise interventions for these children, there is a dearth of evidence-based treatments. This study tested the feasibility of a high-intensity exercise program for children with ASD without ID, and associated changes in physical performance. Method: Fifty-eight children, ages 7-12 with ASD without ID participated. The intervention (5 weeks, 19 sessions, 60 mins ea.) was conducted during the summer. Each session was manualized (operationalized instructional procedure and curriculum) and targeted components of fitness and motor performance using skill development exercises, workouts, and game-related activities. Feasibility was assessed via fidelity (implementation accuracy), satisfaction surveys, attrition, and injuries. Physical performance was tested at baseline and posttest using measures of work production (completed rounds of an exercise circuit) and within-session activity levels (time in moderate-to-vigorous PA), and six exercise tests (sit and reach, push-ups, sit-ups, air squats, long jump, and PACER). Results: Results indicated high levels of fidelity (93.7%) and child and staff satisfaction, and no attrition or injuries, supporting the feasibility, tolerability, and safety of the protocol. Significant increases were found in work production and activity levels (ds 0.83 and 1.05, respectively) and on three exercise tests (sit ups, air squats, and long jump; ds 0.29-0.37). Conclusion: The exercise program was feasible and safe, and completion was associated with significant improvements in multiple areas of performance; a randomized controlled trial appears warranted.

Purpose: This study was aimed to investigate the relationship between athletic performance and physiological characteristics in wheelchair basketball (WB) athletes with different classification scores. Methods: Twenty-six (24 male and 2 female) WB athletes were involved into the study. The participants were divided into two functional categories (Category A:1.0-2.5 points, category B: 3.0-4.5 points) according to the IWBF rules. Shoulder internal (IR) and external rotation (ER) muscle strengths were evaluated with the ISOMED 2000® isokinetic dynamometer. Handgrip strength was evaluated with hydraulic hand dynamometer. Custom ramp protocol on treadmill was employed to measure aerobic capacity. Anaerobic capacity was evaluated with Wingate anaerobic power test in standard laboratory conditions. The athletic performance was assessed by 20 m Sprint test, Slalom Test, and Zone Shot tests. Results: Category B athletes achieved significantly better results in the measurements of shoulder IR and ER muscle strength, aerobic and anaerobic capacity, and athletic performance while the grip strength was found similar in the categories. There was a significant correlation between the athletic performance and shoulder IR and ER muscle strength, and aerobic and anaerobic capacities in two categories. There was no significant relationship between grip strength and athletic performance parameters in two categories. Conclusion: It was concluded that athletic performance in WB athletes with different classification scores is related to upper extremity muscle strength, aerobic, and anaerobic capacity. Additionally, upper limb muscle strength, athletic performance, aerobic and anaerobic capacity assessments to be made will contribute positively to the planning of individual training and exercise programs.

Accurate determinations of individuals' one-repetition maximum (1RM) are critical when evaluating the effectiveness of an exercise intervention involving progressive resistance training (RT). Traditional ("bottom-up"; BT) testing methods involve progressions from low to maximal loads and are commonly used in clinical and laboratory environments. Concerns about the reliability of BT testing in certain populations suggest a different technique may be more effective. Purpose: To compare the reliability and effectiveness of traditional 1RM testing to a novel technique (TDT) involving progressive load reductions and a starting intensity equal to 130% of exercisers' estimated 1RM. Method: 70 healthy adults (age = 45.03 ± 25.64 y) with diverse RT experience were randomized into a reliability testing trial (RTT; n = 33) or an optimal method trial (OMT; n = 37). Subjects in the RTT performed either TDT or BT on 3 occasions separated by = 72 hours, while subjects in the OMT performed each method once in random order on separate days. Results: No significant differences in percent coefficient of variation were observed between BT and TDT for either exercise used in the study (pneumatic seated chest press: Hedge's g = 0.25, p = 0.49; pneumatic recumbent leg press: Hedge's g = 0.12, p = 0.74). TDT was not found to produce significantly higher 1RM values than BT in any group. Conclusion: TDT does not appear to facilitate more reliable 1RM estimates than BT. Further research is needed to determine the stability of these findings across levels of exercisers' age, sex, and previous RT experience.

Purpose: The aim of this study was to propose field-based tests to estimate the anaerobic power of wheelchair basketball athletes. Methods: Eleven lower class wheelchair basketball players performed the Wingate test (WT) and two field-based tests (repeated sprints) of 15 (S-15) and 20 (S-20) meters. The WT provides data in Watts (W). The S-15 and S-20 are recorded in seconds and converted to W using the Running-based Anaerobic Sprint Test (RAST) equation. The participants also completed other field-based tests, such as right and left handgrip strength (HGS) tests and the medicine ball chest pass test. In addition, body mass and height were measured, and the body composition was estimated. The field-based tests and anthropometric measures were used to estimate WT peak power (PP) and mean power (MP) using multiple linear regressions. Results: The field-based tests underestimated the anaerobic power measured with the WT (in W). However, a linear regression model based on S-15 PP, right HGS, height, and body mass explained 76% (P= 0.040) of the WT PP variance. Another model based on S-15 MP and right HGS explained 72% (P= 0.006) of the WT MP variance. Both models had excellent reliability (ICC > 0.90). Conclusion: WT PP can be estimated using S-15 PP (W), right HGS, height, and body mass. The WT MP is predicted using S-15 MP (W) and right HGS. Therefore, a combination of field-based tests and anthropometric measures seem to be appropriate to determine anaerobic power of lower class wheelchair basketball athletes.

Purpose: To estimate temporal trends in broad jump performance for United States youth, a marker of muscular fitness and health. Method: Electronic databases, topical systematic reviews, and personal libraries were systematically searched for studies reporting descriptive standing broad jump data for apparently healthy United States youth (age 10-17 years). Temporal trends at the sex-age level were estimated using sample-weighted regression models associating the year of testing to mean jump performance, with national trends standardized to the year 1985 using a post-stratified population-weighting procedure. Results: Collectively, there was a small increase of 12.6 cm (95%CI: 12.5 to 12.7) or 7.9% (95%CI: 7.1 to 8.6) in 65,527 United States youth between 1911 and 1990. Increases were greater for girls (change in means [95% CI]: 17.1 cm [16.9 to 17.3]; 11.4% [10.7 to 12.2]) compared to boys (change in means [95% CI]: 8.5 cm [8.3 to 8.7]; 4.6% [3.8 to 5.4]), but did not differ between children (10-12 years) and adolescents (13-17 years). Increases in broad jump performance were not always uniform across time, with steady and progressive increases observed for boys and children, respectively, and a diminishing rate of increase observed for girls and adolescents. Conclusions: Muscular fitness is a good marker of health, so greater broad jump performance from 1911 to 1990 may reflect corresponding changes in health. Routine assessment of broad jump performance may be useful to monitor trends in health and muscular fitness of United States youth due to its practicality, scalability, and predictive utility.

Purpose: To analyze the contribution of physical measures and external load in the match-based internal load of elite soccer players. Methods: Twenty-three elite soccer players (n = 23, age 26.69 ± 3.93 years, body mass 78.04 ± 5.03 kg, height 178.04 ± 5.19 cm, body fat 10.98 ± 1.25%) from a first division soccer team of the Brazilian Championship were evaluated first with anthropometric and physical measures (flexibility and muscle power of lower limbs), and after 24 hrs they were asked to perform an incremental treadmill test (VO[subscript 2]max and ventilatory thresholds). Subsequently, athletes were monitored for 6 weeks during nine official matches of a regional championship. On match days, the external load data (e.g., player load) were collected by triaxial accelerometers with GPS systems and post 30 min after the end of the match the internal load was assessed with the Session Rating of Perceived Exertion method (Session-RPE). Results: Our main findings showed significant contributions of the Player Load (r = 0.62, p < 0.001; 42.3%) and Anaerobic Threshold (r = -0.199, p = 0.05, 17%) for the predictive model of Session-RPE. Conclusions: Physical measures and external load have a significant influence on the internal load in elite soccer players. Our findings suggest that sport scientists can use the Session-RPE as a low-cost method for prescribing and monitoring training loads, by the influence of physical measures and external load on the match-based internal load, in order to optimize athletes' performance.

Purpose: The aim of this study was to compare strength-endurance handgrip performance and muscle coactivation between judo athletes and untrained young males. Method: The sample was 38 judo athletes and 38 untrained young males, between 12 and 15 years-old. Maturational status was evaluated by age at peak height velocity. A maximal isometric handgrip test (three 5-s repetitions, with 90-s intervals) and an isometric strength-endurance handgrip test (ten 10-s all-out isometric handgrip repetitions, 20-s intervals) was conducted in dominant (D) and nondominant (ND) hands, using a dynamometer with EMG monitor to detect muscle activation. Results: ANCOVA analysis, controlling for maturational status, showed that judo athletes had higher values of maximal absolute (D = 33.6 ± 8.9 kgf vs 29.1 ± 9.0 kgf; ND = 33.8 ± 9.9 kgf vs 28.1 ± 8.1 kgf) and relative strength to body mass (D = 0.64 ± 0.12 kg/kgf vs 0.57 ± 0.13 kg/kgf; ND = 0.64 ± 0.16 kg/kgf vs 0.56 ± 0.14 kg/kgf). Moreover, judo athletes presented lower strength mean fatigue index (33.2 ± 6.9 % vs 37.9 ± 8.7 %) and muscle coactivation (48 ± 19.8 % vs 57.5 ± 22 %), only in the dominant hand, during the isometric strength-endurance handgrip test. During all repetitions of isometric endurance test there were no group or interaction between factors effects for absolute strength, relative strength and muscle coactivation. Conclusion: In summary, judo athletes present higher maximal absolute and relative strength and strength-endurance performance, concomitantly with decreased muscles co-activation (primary in dominant hand) during handgrip tests.

Purpose: The current study investigated the role of quadriceps and gastrocnemii size and "vastus lateralis" and "gastrocnemius medialis" muscle architecture in peak-power and time-to-peak-power exerted in an all-out Wingate test. Twenty-one amateur cyclists were recruited. Methods: Quadriceps and gastrocnemii anatomical cross-sectional area (ACSA), and "vastus lateralis" and "gastrocnemius medialis" pennation angle and fascicle length were measured using ultrasound. Relative peak-power (normalized per body mass) and time-to-peak-power were measured during a 30s all-out test. Results: Relative peak-power was correlated with quadriceps ACSA (r = 0.896, p < 0.001), gastrocnemii ACSA (r = 0.811, p < 0.001), "vastus lateralis" (r = 0.787, p < 0.001) and "gastrocnemius medialis" pennation angle (r = 0.638, p < 0.003). Multiple regression revealed that quadriceps and gastrocnemii ACSA accounted for 85% (R[superscript 2]= 0.85) of peak-power variance. Time-to-peak-power showed "very large" (r = -0.868, p < 0.001) and "large" correlation (r = -0.680, p = 0.001) with VL and GM fascicle length, respectively. Multiple regression analysis revealed that VL fascicle length explained 75% (R[superscript 2]= 0.75) of the time-to-peak-power variance. Conclusions: Quadriceps and gastrocnemii ACSA largely explained relative peak-power in an all-out Wingate test. "Vastus lateralis" fascicle length was the main predictor of the time-to-peak-power. Muscle architecture characteristics seem to be involved in the power generating capacity.

Purpose: The aim of the study was to evaluate the effects of motor imagery (MI) and action observation (AO) combined with a motor control exercises program for the lumbopelvic region. Method: Forty-five asymptomatic individuals were randomized into three groups: MI (n = 15), AO (n = 15) or control group (CG) (n = 15). The outcome measures included lumbopelvic motor control measured with a stabilizer pressure biofeedback, trunk muscle strength using a dynamometer and the perceived fatigue using a visual analogue scale. Participants were assessed at pre-intervention, at first week of intervention (mid) and post-intervention. Results: Regarding lumbopelvic motor control, we observed significant within-group differences between pre- and the mid and post-intervention assessment in AO group (p < 0.001, d > 0.80). MI and CG groups showed significant differences between pre- and post-intervention assessment (p < 0.05, d > 0.80). Regarding the direct comparison in the [delta]Mid-Pre differences between groups, only the AO group was superior to the CG with a large effect size (d > 0.80). Regarding trunk muscle strength, significant within-group differences between pre- and post-intervention assessments were observed in AO (p < 0.001, d = -1.25) and MI (p < 0.05, d = -1.00) groups. In relation to the perceived fatigue, statistically significant within-group differences were found in all groups (p < 0.05, d > 0.60). Conclusion: AO training caused faster changes in lumbopelvic motor control compared with the CG group. The AO strategy could be used as a guideline for teaching lumbopelvic motor control exercises.

Purpose: The study aimed to test whether improvement in fitness components, mediates the changes in Health-related Quality of Life (HRQoL) after exercise intervention in overweight and obese children. Methods and design: 170 obese and overweight children (121 exercise group and 49 control group) participated in a public exercise program based on sports practice for 6 months, 2 h per week. Anthropometry, physical fitness, and HRQoL were measured. Magnitude-based inferences and Cohen's effect size were performed to analyze the program effect. To know which physical fitness components mediated the improvement on children's HRQoL, multiple mediation analyses were performed. Results: the analysis showed a moderate effect on some fitness components and a moderate and small effect on HRQoL. The improvement of agility or cardiorespiratory fitness showed a significant indirect effect on the enhancements in some HRQoL dimensions. Conclusion: after a 6-months exercise program in overweight and obese children, all physical fitness components improved, being responsible for the improvement of the HRQoL, agility and cardiorespiratory fitness.

Purpose: Inducing a negative stereotype toward women usually leads to a decrease in women performance and an increase in men performance. These effects were observed during technical tasks. The purpose of the present study was to investigate the effect of this sex stereotype during a non-technical muscular endurance task. The perception of effort, closely related to endurance performance, was also recorded. Based on the type of task and the mere effort account, we predicted that both men and women in the negative stereotype toward women condition would perform better than participants in the two other groups. Method: Seventy-seven participants (38 women and 39 men) were randomly assigned to a negative stereotype toward women, a nullified-stereotype, or a control condition. Then, they performed a submaximal handgrip task until exhaustion at 50% of their maximal strength. Results: This study showed that performance at T2 was reduced for men and women in the nullified-stereotype and control conditions, but not in the negative stereotype toward women condition, revealing that participants in the negative stereotype toward women condition performed better than participants in the other conditions. No significant difference was observed concerning the perception of effort according to the conditions. Conclusion: As compared to technical tasks, inducing a negative stereotype toward women increased women's performance. The perception of effort could be responsible for this performance improvement. However, more research is needed to investigate the mechanisms involved. Concerning men, in line with the stereotype lift phenomenon, a performance increase was observed in this same condition.

Purpose: To determine the individual contributions of chronological age, somatic maturation, body size and composition, and training experience as indicators of performance in neuromuscular and judo-specific assessments in young athletes. Methods: Sixty-six youth judo athletes performed anthropometric measurements, neuromuscular tests--standing long jump test (SLJ), medicine ball throw test (MBT), handgrip strength test (HGS), and judo-specific tests--Special Judo Fitness test (SJFT) and Judogi Grip Isometric Strength Test (JGST[subscript ISO]). A multiple linear regression was used with the level of significance set at 5%. Results: The main results showed age-peak height velocity (PHV), body fat and training experience explained close to 20% of SJFT performance. Chronological age, age-PHV, height, body mass and body fat accounted for 42% of variance in JGST[subscript ISO]. Chronological age, body fat and training experience explained 35% of the variance in SLJ, while chronological age, body mass and body fat explained 53% of the variance in MBT. Finally, age-PHV, body mass and height explained 54% of the variance in HGS. Conclusion: Estimated age-PHV and growth variables explained moderate to large proportions of the variance in neuromuscular tests (with exception of SLJ), while both estimated age-PHV, training and growth variables were predictors of judo-specific performance.

Metabolic syndrome (MetS) is a growing epidemic related with higher values of blood pressure (BP) and autonomic dysfunction. Scientific evidence has been indicating that functional resistance training (FRT) is superior over conventional (CRT) for muscle fatigue and pain, yet its effects on autonomic modulation (AM), BP and heart rate in MetS are unclear. We theorized that FRT can be superior to CRT in MetS patients because of larger muscle activation. This study compares FRT and CRT on AM, blood pressure, heart rate and muscle strength. Thirty-eight sex and age matched individuals (40 to 60 years) were randomized for FRT or CRT, with training intensity varying gradually from 30%-100% of one maximal repetition test (1MR), 3 times/week for 30 sessions. All outcomes were evaluated at baseline and post training. AM was assessed by heart rate variability (mean RR, RMSSD, SDNN, LF, HF, TINN, RRtri, SD1 and SD2). BP (mmHg) was obtained by cuff measures. Muscle strength was assessed by 1MR. An increase in cardiac parasympathetic activity was observed in individuals allocated to FRT in comparison to CRT group (RMSSD [delta]40%; SD1 [delta]39%; and HF [subscript ms][superscript 2] [delta]80%). Moreover, just FRT was capable of reducing BP post intervention (SBP from 129.21 ± 19.02 to 118.94 ± 14.14 mmHg, p < 0.009,/d/ = 0.49; DBP from 85.26 ± 11.48 to 77.76 ± 8.93 mmHg, p < 0.01,/d/ = 0.51). Both groups had a similar increase in muscle strength and no changes between HR. Progressive FRT was more beneficial to CRT regarding AM, increasing vagal activity, and reducing blood pressure in MetS individuals.

Purpose: The purpose of this study was to identify the skills, knowledge, and experiences differentiating expert and competent strength and conditioning (S&C) coaches. Method: The participants were 87 elite-level head S&C coaches with an average of over 18 years of coaching experience. These coaches were employed by teams from the MLB, NBA, NFL, NHL, NCAA Division 1 FBS "Power Five" Conferences, United States National Teams, and the Australian Football League. This study used both a qualitative and quantitative research design through the use of the Delphi method, which incorporated three rounds of surveys. The first-round survey asked the participants to identify at least one important skill, knowledge area, and experience that should be possessed by an expert and competent S&C coach respectively. The characteristics generated from the first round were placed on a second-round survey and rated on their level of importance using a five-point Likert scale. If a characteristic received a suggestion for rephrasing, and did not reach a level of consensus, or an entirely new characteristic was suggested, then it was placed on the final-round survey to be rated again. Characteristics that reached a level of consensus were placed on the final list of characteristics. Results: A total of 46 characteristics reached a level of consensus and were placed on the final list of characteristics. Conclusion: There now exists an empirically validated list of characteristics differentiating expert and competent S&C coaches. This list can aid in the selection, evaluation, and development of S&C coaches.

Purpose: The aim of this study was to determine the changes in neuromuscular contractile properties in elite cyclists associated to the peripheral fatigue produced in a maximal incremental test in cycle ergometer. Methods: Forty-eight volunteers' well-trained male cyclists were evaluated during the competition season within a recovery microcycle. Tensiomyography was used before and after performing an incremental test until exhaustion in cycle ergometer to measure the radial muscle belly displacement of the vastus lateralis (VL), rectus femoris (RF), and biceps femoris (BF) on the dominant leg. Maximum radial muscle belly displacement (Dm), contraction time (Tc), delay time (Td), sustain time (Ts), and radial displacement velocity (Vrd) were measured. Mixed-design factorial analysis of variance was used to detect changes in the mechanical and neuromuscular characteristics after a maximal incremental exercise test. Results: The results show in the evaluated muscles a moderate-large decrease (p < 0.01, [eta]2 = 0.06-0.51) in Tc, Td, Dm, Ts, and Vrd. This decrease occurs more sharply in the BF than in RF or VL. Conclusion: An incremental effort until exhaustion produces peripheral fatigue associated with a decrease in Dm, Tc, Td, Ts, and Vrd, being more pronounced in biceps femoris than in vastus lateralis and rectus femoris. Coaches can use these changes found in the contractile properties as a reference to detect the muscle fatigue degree that certain training models pose for the cyclist.

Physical fitness is one of the key factors in healthy aging. Although physical fitness is widely recognized to decline with age, age-related decreases in the individual dimensions of physical fitness in later life are less clear. Purpose: The purpose of the present study was to describe the age-related changes in six fitness components covering a variety of motor dimensions in men and women through a 12-year longitudinal epidemiological study. Method: Participants were randomly selected community-living men (n = 1,139) and women (n = 1,128) aged 40 to 79 years at baseline who were repeatedly tested over a mean (standard deviation) follow-up period of 9.8 (3.4) years with a mean of 4.9 (2.3) examinations. The six physical fitness tests were sit-and-reach, grip strength, sit-ups, one-leg standing, reaction time and leg extension power. The effect of age on each physical fitness task was analyzed using a mixed-effects model controlling for habitual physical activity level. Results: The fixed effect of the interaction of age and time in all fitness tests was significant in men. Higher age at baseline was significantly associated with a greater decrease over time except in one-leg standing. In women, no significant interaction effect of age and time was found in grip strength or reaction time. Age-related changes in grip strength and reaction time were constant with increasing age. Conclusion: Twelve-year longitudinal data showed that the age-related decrease in physical fitness over time, especially musculoskeletal fitness in men, was pronounced, whereas in women, the decrease was less pronounced.

Purpose: To compare the effects of a single bout of eccentric cycling (ECC) and eccentric cycling with blood flow restriction (ECC[subscript BFR]) on the changes in cardio-metabolic demand and indirect markers of muscle damage in healthy men. Method: Twenty-one young men (24.0 ± 3.2 y) were randomly allocated in two groups to perform a 30-min eccentric cycling bout with or without blood flow restriction. Oxygen consumption, heart rate, rate of perceived exertion and mean arterial blood pressure were monitored during cycling. Blood lactate was measured before and after cycling. Maximal voluntary isometric knee extensor strength and muscle damage were measured before, immediately after and 1-4 days after each eccentric cycling bout. Results: Oxygen consumption, heart rate, rate of perceived exertion and mean arterial blood pressure were similar between bouts. Blood lactate concentrations increased in both groups (p < 0.01), with ECC[subscript BFR] showing 60% greater blood lactate concentration than eccentric cycling (p < 0.01). Maximal voluntary isometric knee extensor strength decreased 19-7% until 48 h and decreased 16-7% until 72 h after ECC and ECC[subscript BFR], respectively. Muscle soreness and pressure pain threshold remained elevated until 72 h after ECC and until 96 h after ECC[subscript BFR]. Conclusion: These results show that ECC[subscript BFR] induces similar cardiovascular stress, greater lactate production and longer time to recover than ECC alone. Thus, BFR can be safely implemented with eccentric cycling.

Purpose: This study compared the acute effects of two different resistance training methods on heart rate variability, blood pressure, and rating of perceived exertion in patients with liver cirrhosis. Methods: Ten patients with Child-Pugh A (seven women and three men) participated in two experimental sessions, in random order: The traditional set condition consisted of three sets of six exercises performed in a sequential manner, while the paired set condition consisted of alternating sets between two exercises (three pairs of exercises). Ten repetitions were performed for each set with 70% of a 10 repetition maximum load and with 2 min rest between sets. Blood pressure and heart rate variability were assessed pre-workout and for 60 min post-workout. The rating of perceived exertion was assessed at the end of the third set for each exercise. Results: Significant alterations in heart rate variability were observed when considering the lowest value obtained during recovery, in which the SDNN was reduced in both the traditional set and paired set conditions, as well as the root mean square of standard deviation for the traditional set condition (p < 0.05). Additionally, for the paired set condition, there was a significant reduction in the HFnu band and a significant increase in the LFnu band (p < 0.05). Effect size showed reductions in diastolic and mean blood pressure until 30 min in a small magnitude for traditional sets. Conclusion: Similar cardiovascular responses were observed between methods eliciting normal physiological responses within safe limits for patients with liver cirrhosis.

Purpose: To determine if weight training combined with pelvic floor muscle training is more efficient than pelvic floor muscle training alone for the treatment of urinary incontinence (UI) symptoms in elderly women. Method: This was a two-arm, parallel, randomized controlled trial. Twenty-six women with stress UI participated in the study. The intervention group (IG) underwent training with moderate intensity weights combined with pelvic floor muscle training, whereas the control group (CG) only underwent pelvic floor muscle training. Intervention occurred twice a week over 12 weeks. The International Consultation on Incontinence Questionnaire--Short Form was used as the main measure. Scores of zero defined the absence of symptoms. The absence of symptoms was evaluated at 4 weeks, 12 weeks, and 1 month after the end of treatment. Moreover, activities related to UI and the use and change of daily protection were investigated. Results: The rate of absence of symptoms was significantly higher in IG after 4 weeks (58.3%) compared to CG (14.8%). The relative risk was 4.1 (95% confidence interval [CI] [1.08, 16.06]). Although no intention-to-treat analysis was performed, there was no difference in the evaluations after the interventions. Conclusion: Compared to pelvic floor muscle training alone, the combination of weight training and pelvic floor muscle training provided earlier improvement of UI in elderly women.

Purpose: The purpose of this study was to determine magnitudes of differences for anthropometric and athletic performance scores between high school and elite college-level American football players. Method: Participants included high school-age (n = 3,666) athletes who participated in American football combines, as well as elite college-level (n = 5,537) athletes who participated in the National Football League (NFL) scouting combine. Combine data included position; height; weight; 10-, 20-, and 40-yard dash; pro-agility (PA); L-cone drill (LC); vertical jump (VJ); and broad jump (BJ). Athletes were separated into their respective position group, defensive back (DB), wide receiver (WR), linebacker (LB), quarterback (QB), running back (RB), tight end (TE), defensive line (DL), and offensive line (OL) for analysis of performance differences. Percent differences for each dependent variable were calculated to quantify magnitudes of differences. Results: NFL combine participants scored 3% to 25% better on all measurements, with the largest differences between weight and VJ (14%-25%). Conclusion: The largest measurement-specific differences between high school-age and elite college-level American football players were body size and power. Although it may seem intuitive that elite college-level players would perform better, these data provide a unique perspective to high school players, parents, and coaches, giving new information to use when designing measurement-specific athletic development programs. Thus, strength and conditioning professionals may benefit from emphasizing increases in muscle mass and power output in strength and conditioning programs.

Purpose: This study compared the energy system contributions and relationship between mechanical and energy system variables in upper and lower body Wingate tests (WAnT) in judo athletes. Method: Eleven male judo athletes (18 ± 1 years, 174.3 ± 5.3 cm, 72.6 ± 9.9 kg, 11.8 ± 1.7% body fat) attended two laboratory sessions to perform two WAnT (upper and lower body) and two incremental tests (upper and lower body). The energy contributions of the oxidative, glycolytic, and phosphagen (ATP-PCr) systems were estimated based on oxygen consumption (VO[subscript 2]) during WAnT, delta of lactate, and the fast phase of excess VO[subscript 2], respectively. Results: The upper and lower body presented similar results of oxidative (21 ± 4% vs 23 ± 3%) and ATP-PCr system contributions (29 ± 6% vs 32 ± 5%). The glycolytic system contribution (50 ± 5% vs 45 ± 4%) was higher in the upper body. The variance of mechanical variables in upper body was explained by glycolytic (R[superscript 2] = 0.49-0.62) and oxidative systems (R[superscript 2] = 0.44-0.49), whereas the variance of mechanical variables in lower body was explained by ATP-PCr (R[superscript 2] = 0.41-0.55) and glycolytic systems (R[superscript 2] = 0.62-0.94). Conclusions: During WAnT, the glycolytic system presented the major energy contribution, being higher in the upper body. Moreover, mechanical and energy system variables presented a distinct relationship when comparing upper and lower body WAnT.

Purpose: To compare the effects of three water-based resistance trainings on neuromuscular parameters of older women. Method: Thirty-six women were randomized to groups: simple set of 30 seconds (1 × 30 s, 66.41 ± 4.71 years, n = 12), multiple sets of 10 seconds (3 × 10 s, 66.50 ± 4.74 years, n = 11), and simple set of 10 seconds (1 × 10 s, 65.23 ± 3.93 years, n = 13). Maximal isometric strength concomitantly with neuromuscular activity during extension and flexion knee was evaluated. In the same exercises, rate of force development at different time intervals was measured. Finally, functional capacity was assessed. Results: All trainings promoted similar improvements in the rate of force development of extension (effect size RFD 50 ms: 1 × 30 s 0.49, 3 × 10 s 0.67, 1 × 10 s 0.65; ES RFD 100 ms: 1 × 30 s 0.76, 3 × 10 s 0.80, 1 × 10 s 0.63; ES RFD 250 ms: 1 × 30 s 0.31, 3 × 10 s 0.49, 1 × 10 s 0.37) and flexion knee (ES RFD 50 ms: 1 × 30 s 0.59, 3 × 10 s 0.31, 1 × 10 s 0.48; ES RFD 100 ms: 1 × 30 s 0.41, 3 × 10 s 0.44, 1 × 10 s 0.42; ES RFD 250 ms: 1 × 30 s 0.57, 3 × 10 s 0.36, 1 × 10 s 0.43; ES RFD maximal: 1 × 30 s 0.63, 3 × 10 s 0.23, 1 × 10 s 0.26), however only the 3 × 10 s group improved the performance in the 8-foot up-and-go test (ES 3 × 10 s: 0.93, 1 × 30: 0.39, 1 × 10 s: 0.23). There was a maintenance of the isometric force and neuromuscular activity, except for the activity of the rectus femoris that showed an increase after training in all groups (ES 3 × 10 s: 0.04, 1 × 30: 0.36, 1 × 10 s: 0.50). Conclusion: Water-based resistance training using simple or multiple sets promotes the same gains in rapid strength, however only multiple sets induced improvement on functional capacity.

Purpose: The aim of this study was to test the effects of chair-based exercise programs on salivary stress hormones, physical fitness, and functional autonomy of institutionalized older women. Method: In total, 47 participants (80 ± 8.04 years old) were recruited and allocated into three groups: chair-based aerobic exercises (CAE, n = 19), chair-based elastic-band strength exercises (CSE, n = 15), and a control group (CG, n = 13). A 14-week exercise intervention was done for the CAE and CSE groups, two times per week, in no consecutive days. Members of the CG did not participate in any type of exercise but kept their regular lifestyle. Fear of falling, autonomy, physical fitness, salivary cortisol, and alpha-amylase levels were assessed before and after the intervention. Results: The CAE group improved upper and lower body strength, agility--dynamic balance, and autonomy, with fear of falling decreasing significantly (p < 0.05, moderate effect size). Both exercise groups showed a trend toward an increase in salivary alpha-amylase levels (CAE = 43%, d = 0.31, and CSE = 44%, d = 0.41). Conclusion: Both exercise programs were able to improve functional autonomy, even in elders older than 80 years of age. It might be interesting to investigate the effectiveness of combining both aerobic and strength exercises in a unique protocol. The modulation effect of exercise in the hormonal responses needs to be further explored.

Purpose: Resistance training is often performed in a traditional training style using deliberate relatively longer repetition durations or in an explosive training style using maximal intended velocities and relatively shorter repetition durations. Both improve strength, "power" (impulsivity), and speed. This study compared explosive and traditional training over a 6-week intervention in 30 healthy young adult male recreational soccer players. Method: Full body supervised resistance training was performed 2 times a week using 3 sets of each exercise at 80% of one repetition maximum to momentary failure. Outcomes were Smith machine squat 1 repetition maximum, 10 meter sprint time, and countermovement jump. Results: Both groups significantly improved all outcomes based on 95% confidence intervals not crossing zero. There were no between-group differences for squat 1 RM (TRAD = 6.3[5.1 to 7.6] kg, EXP = 5.2[3.9 to 6.4] kg) or 10 meter sprint (TRAD = -0.05[-0.07 to -0.04] s, EXP = -0.05[-0.06 to -0.03] s). Explosive group had a significantly greater increase in countermovement jump compared to the traditional group (TRAD = 0.7[0.3 to 1.1] cm, EXP = 1.3[0.9 to 1.7] cm). Conclusion: Both the traditional training and explosive training performed to momentary failure produced significant improvements in strength, speed, and jump performance. Strength gains are similar independent of intended movement speed. However, speed and jump performance changes are marginal with resistance training.

Purpose: To evaluate vascular function and its relationship to cardiorespiratory fitness in professional handball athletes. Method: We examined 30 male professional handball athletes (age 27 [plus or minus] 4 y) and 10 male sedentary controls (age 26[plus or minus] 5 y) at rest. The workup included exercise testing via ergometry. To assess vascular function, a validated electronic model of the arterial tree (vasc assist 2 [Registered Trade Mark]) was used. It replicates noninvasively acquired pulse pressure waves by modulating the relevant functional parameters of compliance, resistance, inertia, pressure, and flow. The maximum oxygen uptake (VO2max) was estimated using the validated heart rate ratio method. Results: Athletes had a significantly lower systolic and diastolic central blood pressure ([mini c]BP) compared to controls (102[plus or minus]9/60[plus or minus] 9 vs. 110[plus or minus]8/74[plus or minus]9 mmHg, p[less than] 0.01), whereas aortic pulse wave velocity (PWV) (6.2[plus or minus]0.8 vs. 6.3[plus or minus] 0.5 m/s, p = 0.45) and augmentation index at a heart rate of 75 (Aix[at]75) (-4[plus or minus]12 vs. -13[plus or minus]16%, p = 0.06) were not different. Resistance index (R) (15.9[plus or minus]4.4 vs. 10.6[plus or minus]0.6, p = 0.001) and maximum power output (MPO) (3.55 [plus or minus]0.54 vs. 2.46[plus or minus]0.55 Watt/kg, p[less than] 0.001) were significantly higher in athletes compared to controls. We found no relevant correlation between MPO, resting heart rate, PWV, Aix[at]75, and cBP. A higher VO2max (p = 0.02) and a lower R (p[less than]0.01) were significant predictors of a higher MPO in athletes. Conclusion: R had an independent and strong correlation to MPO in athletes, which might help to disentangle the contribution of aerobic capacity and arterial function to physical power.

Purpose: Trampoline parks are becoming popular in many countries, providing recreational facilities for children and adults. This study investigated the effects of trampoline training on knee muscles strength and balance in young adults. Methods: Twenty-six participants (14 males, 12 females) were randomized into trampoline training (TT) and resistance training (RT) groups to undergo a 6-week supervised intervention program (2 × 30 min per week). TT group performed basic trampoline exercises while the RT group performed resistance training targeting lower extremities muscles. Peak knee extension and flexion torque, postural sway characteristics, and Y balance test (YBT) performance were evaluated before and after the intervention. A mixed model analysis of variance (group × time) was applied. Results: After training there were significant improvements in knee extension torque (mean difference[subscript post-pre] [95% CI], TT: 0.27 [0.00, 0.54] N·m/kg, RT: 0.31 [0.09,0.54] N·m/kg, p = 0.001), knee flexion torque (TT: 0.25 [0.17,0.33] N·m/kg, RT: 0.21 [0.08,0.34] N·m/kg, p < 0.001), and dynamic balance (YBT composite scores, mean difference[subscript post-pre] [95% CI], TT: 4.9 [-0.3, 10.2]%, RT: 5.2 [2.4,8.0]%, p = 0.001). No difference between groups was found. Conclusion: Trampoline training can be as effective as resistance training for improving knee muscles strength and dynamic balance in young men and women.

Purpose: This study aims to analyze changes in Maximum Inspiratory Pressure (MIP), lung function, cardiorespiratory fitness, and blood pressure, in 10 healthy active elderly women, following 7 weeks of inspiratory muscle training (IMT) combined with a multicomponent training program (MCTP). The association among these health parameters, their changes after training (deltas), and the influence of MIP at baseline (MIP[subscript pre]) are also considered. Methods: IMT involved 30 inspirations at 50% of the MIP, twice daily, 7 days a week, while MCTP was 1 hr, twice a week. MIP, lung function (FVC, FEV[subscript 1], FEV[subscript 1]/FVC, FEF[subscript 25-75%], PEF), 6MWT, and blood pressure (SBP, DBP), jointly with body composition, were assessed before and after the intervention. Results: Seven weeks were enough to improved MIP (p = 0.019; d = 1.397), 6MWT (p = 0.012; d = 0.832), SBP (p = 0.003; d = 1.035) and DBP (p = 0.024; d = 0.848). Despite the high physical fitness (VO[subscript 2] peak: M = 23.38, SD = 3.39 ml[middle dot]min[middle dot]Kg[superscript -1]), MIP[subscript pre] was low (M = 39.00, SD = 7.63 cmH[subscript 2]O) and displayed a significant negative correlation with [delta]MIP[subscript pre-post] (r = -0.821; p < 0.004), showing that women who started the intervention with lower MIP achieved higher improvements in inspiratory muscle strength after training. Conclusions: No significant changes in spirometric parameters may signal that lung function is independent of early improvements in inspiratory muscles and cardiorespiratory fitness. Absence of correlation between physical fitness and respiratory outcomes suggests that being fit does not ensure cardiorespiratory health in active elderly women, so IMT might be beneficial and should supplement the MCTP in this population.

A quick, well-timed pelvic-floor muscle contraction during physical effort is recommended for active women to prevent urine leakage. Purpose: We address two research questions: how well do future female exercise professionals contract the pelvic-floor muscles, and whether the biofeedback session is necessary to train them to contract pelvic-floor muscles? Method: Participants were 84 nulliparous future exercise professionals (age 23 ± 3 years, mean ± SD), randomly allocated into biofeedback (n = 27), usual-advice (n = 26), and control (no advice, n = 21) groups. Contraction of pelvic-floor muscles on a 4-point scale (1 = incorrect through 4 = correct) was assessed in all groups by surface electromyography (sEMG) with a vaginal probe before and after 6 weeks of intervention. Results: In pretest, almost one in five participants (17%) could not activate the pelvic floor and less than half of them (45%) presented correct technique. The technique score for the three groups was 3.1 ± 1.1 (mean ± SD). After training, both intervention groups presented better technique score by 0.6 (90% confidence limits ± 0.5) relative to the control group, and two-thirds (65%) of the intervention groups presented the correct technique. Conclusions: Future exercise professionals displayed poor skills in contracting pelvic-floor muscles. Both training interventions (with and without biofeedback) were effective for this study group.

Purpose: The purpose of this study was to investigate (a) time-dependent changes in muscle damage (MD) biomarkers, oxidative stress (OS) indices, and maximum strength performance; (b) the relationship between changes in maximum strength performance and changes in MD and OS indices; and (c) whether eccentric exercise-induced MD is related to OS. Method: Twenty-nine male volunteers (age: 22.13 ± 3.1 years) participated in the study. Participants performed 60 maximal eccentric actions of the elbow flexors at a constant velocity of 60°·s[Superscript -1]. Maximum isokinetic strength (MIS), visual analog scale soreness scores, serum creatine kinase (CK) activity, total antioxidant status, total oxidant status (TOS), protein carbonyl (PCO), and 8-hydroxydeoxyguanosine level were analyzed. Blood samples were obtained before, immediately after, and 24 h, 48 h, and 96 h after the eccentric exercise. Change in total work (%?TWk), peak torque (%?PT), and OS index were calculated. Results: CK, PCO, and TOS significantly increased over time (p < 0.05). However, no significant main effect was observed for MIS or any other investigated biomarkers (p > 0.05). MIS was not related to MD or OS indices. However, %?TWk demonstrated a moderate inverse correlation with OS indices. No significant relationship was observed between %?PT and any of the selected biomarkers. Conclusions: Our findings confirm the hypothesis that acute eccentric exercise increases MD biomarkers and OS indices. However, indices of OS damage were significantly related, particularly, to the strength loss of flexors. This finding suggests that the decline in strength performance is not the primary determinant of the magnitude of MD following voluntary eccentric contraction.

Purpose: The present study aimed to investigate whether or not eccentric-only training induced different sex-related adaptations in vastus lateralis muscle architecture and knee extensors strength. Methods: Thirteen healthy women and 13 healthy men were recruited. Vastus lateralis pennation angle, fascicle length, and muscle thickness, as well as knee extensors eccentric, isometric, and concentric peak torque and one-repetition maximum (1RM) were measured. Both women and men underwent a unilateral iso-load knee-extension eccentric-only training with 120% of the concentric 1RM, consisting of 4 sets × 10 repetitions twice a week for a total of 8 weeks. Results: Pennation angle increased in women (+ 14%, 95% CI [10, 17], effect size [ES] = 1.54) but not in men (+ 5%, 95% CI [-1, 11], ES = 0.28), while fascicle length increased in both women (+ 7%, 95% CI [4, 10], ES = 1.02) and men (+ 12%, 95% CI [8, 16], ES = 1.82) and muscle thickness increased in women (+ 13%, 95% CI [8, 18], ES = 1.11) and men (+ 11%, 95% CI [7, 15], ES = 0.89). In both women and men, eccentric (18%, 95% CI [11, 25], ES = 0.96, and 16%, 95% CI [9, 22], ES = 0.82, respectively), isometric (17%, 95% CI [11, 23], ES = 0.53, and 17%, 95% CI [10, 24], ES = 0.62), concentric (12%, 95% CI [7, 16], ES = 0.49, and 9%, 95% CI [5, 13], ES = 0.42) peak torque and 1RM (10%, 95% CI [6, 14], ES = 0.53, and 10%, 95% CI [5, 15], ES = 0.50) similarly increased after the intervention. Conclusions: This study showed that the adaptations in strength are not sex-dependent, but the increases in pennation angle only in women suggest that the changes in muscle architecture may depend on sex.

Guidelines for improving maximal concentric strength through resistance training (RT) have traditionally included large muscle-group exercises, full ranges of motion, and a load approximating 85% of the 1-repetition maximum (1RM). Supramaximal eccentric training (SME; controlled lowering of loads above the concentric 1RM) has also been shown to be effective at increasing concentric 1RM in the lower body, but concerns regarding injury risk, postexercise soreness, and null benefit over traditional methods (TRAD) may limit the practical utility of this approach. Purpose: The purpose of this study was to determine whether SME elicits greater lower-body strength improvements than TRAD. Method: Key inclusion criteria were regular exercise modalities typical of nonspecialized exercise facilities (e.g., leg press; key exclusion: isokinetic dynamometer) and at least 6 weeks of RT exposure, leading to 5 studies included in the current meta-analysis. Unbiased effect-size measures that quantify the mean difference in lower-body 1RM between SME and TRAD were extracted. Results: Supramaximal eccentric training did not appear to be more effective than TRAD at increasing lower-body 1RM (ES[overbar] = 0.33, SE= 0.26, z = 1.26, 95% CI [-0.20, 0.79], p = 0.20, I[superscript 2] = 56.78%) under a random-effects model where between-study variance was estimated using maximum likelihood estimation ([tau] 2 = 0.25). Conclusion: The selection of SME over TRAD in RT programs designed to increase lower-body 1RM does not appear warranted in all populations. Further research should clarify the merit of periodic SME in TRAD-dominant RT programs as well as whether a differential effect exists in trained individuals.

Purpose: The purpose of this study was to investigate the acute effects of water-based aerobic exercises on the performance of water-based resistance exercises by assessing kinematic parameters during protocols and neuromuscular responses after them. Method: Ten women performed 2 water-based protocols (i.e., resistance and concurrent water-based exercises) on separate days. We evaluated isometric force and electromyographic signal (sEMG) before and after protocols and analyzed kinematic parameters during a water-based resistance exercise. Results: There was no significant difference between knee extension force production and sEMG from the vastus lateralis during the maximal voluntary contraction performed before and after the protocols. However, sEMG from the rectus femoris presented a significant difference between pretest and posttest measurements in both water-based protocols with greater values in the measurement after the end of the protocol (p = 0.046). The peak angular velocity of knee extension and mean angular velocity of knee extension and flexion showed similar values among the sets, with no difference between protocols. The peak angular velocity of knee flexion presented greater values in the water-based resistance exercises compared with the water-based concurrent protocol in the last set (p < 0.001). Conclusion: The main impairment induced by the water-based concurrent exercises was the lower peak angular velocity in the knee flexors compared with water-based resistance exercises alone.

Purpose: The purpose of this study was to determine the impact of adjunctive resistance training (RT) in aerobically trained patients with coronary artery disease on systolic blood pressure (SBP), heart rate (HR), rating of perceived exertion (RPE; using the traditional 6-to-20 scale), and rate-pressure product (RPP) responses to lifting fixed submaximal workloads. Additionally, pretest and posttest RT measures of brachial artery reactivity were obtained. Method: Fifteen patients with coronary artery disease (M[subscript age] = 66.1 ± 5.1 years) who were already performing regular aerobic exercise completed an adjunctive 12-week progressive RT program. Prior to and immediately after the training period, hemodynamic responses and RPE were obtained while participants performed one set of exercises including the bicep curl (BC), shoulder press (SP), and leg press (LP) at individually determined fixed submaximal loads, using ~ 60% to 80% of estimated maximal voluntary contraction. Vascular function was assessed by flow-mediated vasodilation (FMD) testing before and after training. Results: Attenuated hemodynamic and RPE responses for all variables were observed. Meaningful changes were attained for RPP ([HR × SBP] / 100) during BC (106 ± 27 mmHg × beats/min × 10[superscript -2] to 91 ± 22 mmHg × beats/min × 10[superscript -2], d = 0.6, p < 0.05) and SP (102 ± 24 mmHg × beats/min × 10[superscript -2] to 86 ± 17 mmHg × beats/min × 10[superscript -2], d = 0.8, p < 0.05). Rating of perceived exertion decreased significantly during all exercises (d ranging from 1.8 to 3.1, p < 0.05): BC (14.3 ± 2.6 to 9.7 ± 1.6), SP (13.9 ± 1.6 to 9.2 ± 1.5), and LP (14.3 ± 1.4 to 10.3 ± 1.6). Peak group FMD responses were 12.8% and 10.3% dilation at pretraining and posttraining, respectively (p > 0.05). Five of the 15 participants showed modest improvements in their posttraining time to achieve maximum dilation from a mean of 117 s to 81 s, although this change was not statistically significant (p > 0.05). Conclusion: Among aerobically trained cardiac patients, a supplemental RT program resulted in decreased hemodynamic and RPE responses to lifting fixed submaximal workloads.

Purpose: An advanced system for the assessment of climbing-specific performance was developed and used to: (a) investigate the effect of arm fixation (AF) on construct validity evidence and reliability of climbing-specific finger-strength measurement; (b) assess reliability of finger-strength and endurance measurements; and (c) evaluate the relationship between finger flexor all-out test scores and climbing ability. Methods: To determine the effect of AF, 22 male climbers performed 2 maximal strength and all-out tests with AF (shoulder and elbow flexed at 90 degrees) and without AF (shoulder flexed at 180 degrees and elbow fully extended). To determine reliability, 9 male climbers completed 2 maximal strength tests with and without AF and an all-out and intermittent test without AF. Results: The maximal strength test without AF more strongly determined climbing ability than the test with AF (r[superscript 2] = 0.48 and r[superscript 2] = 0.42 for sport climbing; r[superscript 2] = 0.66 and r[superscript 2] = 0.42 for bouldering, respectively). Force and time variables were highly reliable; the rate of force development and fatigue index had moderate and low reliability. The maximal strength test with AF provided slightly higher reliability than without AF (intraclass correlation coefficient [ICC] = 0.94, ICC = 0.88, respectively). However, smaller maximal forces were achieved during AF (484 ± 112 N) than without AF (546 ± 132 N). All-out test average force had sufficiently high reliability (ICC = 0.92) and a relationship to sport climbing (r[superscript 2] = 0.42) and bouldering ability (r[superscript 2] = 0.58). Conclusion: Finger strength and endurance measurements provided sufficient construct validity evidence and high reliability for time and force parameters. Arm fixation provides more reliable results; however, the position without AF is recommended as it is more related to climbing ability.

Purpose: This study explored the effect of whole-body vibration (WBV) using accelerations of 2.56 "g" to 7.68 "g" on lower-body detraining. Methods: All participants (N = 20) were trained using a lower-body resistance-training program for 30 min twice per week from Week 0 to Week 6. At the end of the program, they were randomly assigned to a control group that performed no further training or a WBV group that performed a progressive static WBV program. Data for the 5-repetition-maximum (5RM) squat and extensors and flexors of the knee and ankle were collected at Weeks 0, 6, 8, 10, and 12 for all participants. Results: Two-way (condition vs. time) analysis of variance revealed that although the WBV group maintained strength in the 5RM from Week 6 through Week 8 and the control group had a lower 5RM in Week 8 from Week 6, no differences in the 5RM squat existed between the groups at Week 8. Two-way factorial multivariate analysis of variance revealed no differences between the groups at any of the time for torque of knee flexion, dorsiflexion, or plantar flexion. Conclusion: Static WBV of 2.56 "g" to 7.68 "g" did not attenuate detraining of the flexors and extensors of the knee and ankle.

Purpose: Excess postexercise oxygen consumption (EPOC) is dependent on intensity, duration, and mode of exercise. The purpose of this study was to compare the effect of both exercise mode and intensity on EPOC while controlling for caloric expenditure and duration. Method: Ten low to moderately physically active men (22 ± 2 yrs) performed 3 nonrandomized isocaloric bouts of exercise separated by 7 days. The 1st session was resistance training (RT), followed by moderate-intensity steady-state (SS) aerobic exercise, and concluding with a high-intensity intermittent (IT) aerobic session. Results: Total energy expenditure, rate of energy expenditure, and duration did not differ among trials (p>0.05). Respiratory exchange ratio was greater during the RT trial than the SS trial (p < 0.05). At 12 hr postexercise, resting metabolic rate (RMR) was higher after the RT trial (4.7 ± 0.67 mL/kg/min) and IT trial (4.6 ± 0.62 mL/kg/min) compared with their respective baseline measurements (p < 0.008) and the SS trial (4.3 ± 0.58 mL/kg/min; p < 0.008). At 21 hr postexercise, RMR was higher after the RT trial (3.7 ± 0.51 mL/kg/min) and IT trial (3.5 ± 0.39 mL/kg/min) compared with the SS trial (3.2 ± 0.38 mL/kg/min; p < 0.008). The SS trial did not influence RMR at either 12 hr or 21 hr postexercise. Conclusion: Both RT and IT aerobic work increased EPOC to a greater degree than did SS work, indicating that either mode may be more effective at increasing total daily caloric expenditure than SS aerobic exercise.

Purpose: The purpose of this study was to investigate the physiological adaptations of resistance training (RT) in prepubertal boys. Methods: Eighteen healthy boys were divided into RT (n = 9, M[subscript age] = 10.4 ± 0.5 years) and control (CTR; n = 9, M[subscript age] = 10.9 ± 0.7 years) groups. The RT group underwent a resistance training during 12 weeks, 3 times per week, performing 3 sets of 6 to 15 repetitions at intensities ranging from 60% to 80% of maximal dynamic strength (1-repetition maximum [1-RM] values). Before and after the training, the groups were assessed in their body mass and composition (dual-energy X-ray absorptiometry), isokinetic dynamometry, 1-RM, and ergoespirometry. Moreover, force per unit of muscle volume was calculated by the quotient between 1-RM and lean mass. Results: Both groups presented statistically significant (p < 0.05) increases in the 1-RM and force per unit of muscle volume in the knee extension and elbow flexion, but these strength increases were statistically significantly greater in the RT group (effect size [ES] = 2.83-9.00) than in the CTR group (ES = 0.72-1.00). Moreover, both groups statistically significantly increased in lean body mass variables (ES = 0.12-0.38). However, increases in the fat mass variables occurred only in the CTR group (ES = -0.01-0.50), whereas no changes were observed in the RT group. Furthermore, there were statistically significant increases in all bone mineral content variables (ES = 0.13-0.43), without differences between groups. No cardiorespiratory changes were observed. Conclusion: Twelve weeks of RT was effective in improving strength and force per unit of muscle volume and prevented fat mass increases in boys.

Purpose: The purpose of this study was to examine age- and sex-related variation in handgrip strength and to determine reference values for the Hungarian population. Method: A sample of 1,086 Hungary youth (aged 11-18 years old; 654 boys and 432 girls) completed a handgrip strength assessment using a handheld dynamometer. Quantile regression was used to compute separate models for boys and girls and included a linear, cubic, and quadratic term for age to account for nonlinear patterns. These terms were tested for statistical significance using the Wald statistical test with p < 0.05. Age- and sex-specific centiles were generated and the 50th percentile was used to describe the overall patterns in handgrip strength. Results: The linear, cubic, and quadratic terms for age fitted the data well for boys (p < 0.05), while both linear and quadratic terms for age were statistically significant for girls (p < 0.05). The 50th percentile values resulted in 21.4 kg, 21.7 kg, 25.0 kg, 30.0 kg, 35.4 kg, 40.0 kg, 42.6 kg, and 42.0 kg for boys aged 11 to 18 years old, respectively. The same percentile resulted in 20.0 kg, 19.5 kg, 19.6 kg, 20.3 kg, 21.6 kg, 23.5 kg, 26.1 kg, and 29.2 kg for girls aged 11 to 18 years old, respectively. Conclusions: Muscle strength as determined by handgrip has distinct age-related patterns in boys and girls. We have accounted for biological age differences and developed norm-referenced values that can be used to interpret handgrip assessment scores obtained from school-aged children in Hungary.

Purpose: The purpose of this study was to examine age and sex trends in anaerobic power assessed by a standing broad jump and to determine norm-referenced values for youth in Hungary. Method: A sample of 2,427 Hungarian youth (1,360 boys and 1,067 girls) completed the standing broad jump twice, and the highest distance score was recorded. Quantile regression was used to fit standing broad jump trends across linear and quadratic functions of age. Statistical significance was determined with bootstrap confidence intervals and the Wald test with p < 0.05. Age-by-sex specific centiles were generated and the 50th percentile was used to describe the overall patterns. Results: Standing broad jump scores increased steadily in boys from age 11 through 18 years with a discrete plateau at the end of adolescence. Girls' standing broad jump scores of those who performed above the median increased with age and plateaued later in the adolescence. Both linear and quadratic age terms were statistically significant predictors of standing broad jump trends across age (p < 0.05), but the relations varied depending on the percentile. The 50th percentile values resulted in 147.0 cm, 162.0 cm, 175.0 cm, 186.0 cm, 195.0 cm, 202.0 cm, 207.0 cm, and 210.0 cm for boys aged 11 to 18 years old, respectively, and 140.0 cm, 143.9 cm, 147.3 cm, 150.0 cm, 152.1 cm, 153.7 cm, 154.6 cm, and 155.0 cm for girls aged 11 to 18 years old, respectively. Conclusions: This study provides normative reference charts that take into account age and sex differences in standing broad jump performance. The proposed reference values can be used to interpret standing broad jump scores in Hungarian youth.

Purpose: The purpose of this study was to examine region, age, and sex profiles of physical fitness in Hungarian youth. Method: A sample of 2,602 Hungarian youth aged 10 to 18 years old completed a series of physical fitness field tests: the Progressive Aerobic Cardiorespiratory Endurance Run (PACER) fitness test, body mass index (BMI), percent body fat (%BF), waist circumference (WC), curl-ups (CU), pushups (PU), trunk extension (TE), back-saver sit-and-reach (SR), handgrip (HG), and standing broad jump. Physical fitness scores were classified using FITNESSGRAM® standards, and trends for region, age, and sex were examined using logistic regression. The outcome variable represented the likelihood that a child would meet the recommended levels of fitness for health. Results: Achievement rates varied considerably by region, age, and sex. The likelihood of achieving the Healthy Fitness Zone (HFZ) varied among Hungarian regions and on all the assessments (p < .05) with exception of the CU, PU, and HG tests (p > 0.05). The likelihood of achieving the HFZ was linearly related with age based on PACER, BMI, WC, %BF, CU, and SR scores (p < 0.05). There were statistically significant gender differences and boys were more likely to achieve the HFZ based on PACER, WC, CU, PU, TE, and SR scores (p < 0.05). Conclusions: The likelihood of achieving the recommended levels of fitness for youth varies between regions in Hungary, in most cases decreases with age, and tends to be higher in boys. This study is one of the few that provides evidence of regional, age, and sex patterns of health-related fitness using a representative sample of youth.

Purpose: This study examined the effects of strength training on alternating days and endurance training on consecutive days on running performance for 6 days. Methods: Sixteen male and 8 female moderately trained individuals were evenly assigned into concurrent-training (CCT) and strength-training (ST) groups. The CCT group undertook strength training on alternating days combined with endurance training on consecutive days for 6 days. One week later, the CCT group conducted 3 consecutive days of endurance training only to determine whether fatigue would be induced with endurance training alone (CCT-Con). Endurance training was undertaken to induce endurance-training stimulus and to measure the cost of running (CR), rating of perceived exertion (RPE), and time to exhaustion (TTE). The ST group undertook 3 strength-training sessions on alternating days. Maximal voluntary contraction (MVC), rating of muscle soreness (RMS), and rating of muscle fatigue (RMF) were collected prior to each strength and endurance session. Results: For the CCT group, small differences were primarily found in CR and RPE (ES = 0.17-0.41). However, moderate-to-large reductions were found for TTE and MVC (ES = 0.65-2.00), whereas large increases in RMS and RMF (ES = 1.23-2.49) were found prior to each strength- and endurance-training session. Small differences were found in MVC for the ST group (ES = 0.11) and during CCT-Con for the CCT group (ES = 0.15-0.31). Conclusion: Combining strength training on alternating days with endurance training on consecutive days impairs MVC and running performance at maximal effort and increases RMS and RMF over 6 days.

The purpose of this article is to bring attention to the 10 most pressing questions relevant to musculoskeletal physical fitness testing in children and adolescents. The goal is to stimulate research to answer these questions. The most pressing needs include establishing definitive links between valid, reliable, and feasible field test measures of muscular strength, endurance, power, and flexibility and health risk factors/markers in children and adolescents; determining the effects of exercise training on these relationships; and documenting the tracking of these relationships. The role of flexibility in health-related physical fitness (HRPF) needs to be carefully and specifically examined. Although body weight/composition is a separate component of health-related fitness, it is also a factor that can influence the performance of musculoskeletal test items. The role of body weight, body fat, and central adiposity and the possibility of adjustment of tests results are important research questions. Several questions relate to which field tests are best for use in schools. Finally, actual health-related criterion-referenced cutoff values need to be developed. In conclusion, more quality research is needed to firmly establish the musculoskeletal area for HRPF in youth.

Purpose: To describe those who reported meeting the "2008 Physical Activity Guidelines for Americans" ("2008 Guidelines") muscle-strengthening standard of 2 or more days per week, including all seven muscle groups, and to assess the type and location of muscle-strengthening activities performed. Method: Data from HealthStyles 2009, a cross-sectional, consumer mail-panel survey, was used for analyses ("n" = 4,271). The prevalence estimates with 95% confidence intervals of those meeting the "2008 Guidelines" standards were calculated. Pairwise "t"-tests were performed to examine differences between estimates, tests for linear trends were performed among age, education, and body mass index (BMI) groups, and differences and trends were considered statistically significant at "p" less than 0.05. Results: Overall, 6.0% of participants reported meeting "2008 Guidelines," and there were no significant differences between sex and racial/ethnic groups. A significant linear increase was noted among education groups, with respondents who reported lower levels of educational attainment having lower levels of participation compared with respondents who reported higher levels of educational attainment. A significant linear decrease was noted among each BMI group, with those classified as underweight/normal reporting higher levels of participation, compared with those classified as obese. Free weights and calisthenics were the most common types of activities; the home was the most common location. Conclusions: Few adults reported meeting current muscle-strengthening standards. Future public health efforts to increase participation should use the most frequently reported type and location of muscle-strengthening activities outlined in this study to guide interventions and communication campaigns. (Contains 1 figure and 3 tables.)

Purpose: To quantify creatine kinase (CK) activity changes across time following an acute bout of whole-body vibration (WBV) and determine the association between changes in CK activity and jumping performance. Method: Twenty-six elite young basketball players were assigned to 3 groups: 36-Hz and 46-Hz vibration groups (G36 and G46, respectively) and a control group. The study quantified CK activity and jumping performance following an acute bout of WBV at 2 vibration frequencies. Both WBV groups performed a protocol that consisted of 10 sets of 60 s of WBV while standing on a vibration plate in a quarter-squat position. CK activity, countermovement jumps (CMJ), and squat jumps (SJ) were measured immediately before and 24 hr and 48 hr after WBV. In addition, CMJ and SJ were also measured 5 min after WBV. Results: CK activity was statistically significantly increased 24 hr following WBV in G36 and G46. At 48 hr after WBV, CK activity was similar to baseline levels in G36 but remained statistically significantly above baseline levels in G46. The CMJ and SJ heights were statistically significantly decreased at 5 min following the protocol for both WBV groups. Overall, the changes in CK activity did not present a strong relationship with the changes in jump heights for any of the comparisons. Conclusions: These findings suggest that WBV protocols with such characteristics may not cause excessive muscle damage and may partly explain why many WBV training studies have failed to elicit increases in strength performance.

Purpose: This study compared the relative peak torque and normalized electromyographic (EMG) mean frequency (MNF) responses during fatiguing isokinetic muscle actions for men versus women. Method: Twenty men M[subscript age] ± SD = 22 ± 2 years) and 20 women M[subscript age] ± SD = 22 ± 1 years) performed 50 maximal concentric isokinetic muscle actions of the leg extensors at a velocity of 180°/s while surface EMG signals were detected from the vastus lateralis, rectus femoris, and vastus medialis. The dependent variables were initial, final, and average peak torque; percent decline; the estimated percentage of fast-twitch fibers for the vastus lateralis; and the linear slope coefficients and y-intercepts for normalized EMG MNF versus repetition number. The data were analyzed with independent-samples "t" tests and 2-way mixed-factorial analyses of variance. Results: The mean initial, final, and average peak torque values for men were greater than those for women. There were no mean differences for percent decline and the estimated percentage of fast-twitch fibers for the vastus lateralis. There were also no sex differences for the linear slope coefficients, but there were differences among the muscles (vastus medialis>vastus lateralis>rectus femoris). The mean y-intercept for the vastus lateralis for men was greater than that for women. Conclusions: Men demonstrated greater peak torque values than those for women, but the declines in peak torque and normalized EMG MNF were similar between the sexes. The vastus medialis was more fatigue-resistant than both the vastus lateralis and rectus femoris.

This review examines the influence of dehydration on muscular strength and endurance and on single and repeated anaerobic sprint bouts. Describing hydration effects on anaerobic performance is difficult because various exercise modes are dominated by anaerobic energy pathways, but still contain inherent physiological differences. The critical level of water deficit ([approximately] 3-4%; mode dependent) affecting anaerobic performance is larger than the deficit ([approximately] 2%) impairing endurance performance. A critical performance-duration component (greater than 30 s) may also exist. Moderate dehydration ([approximately] 3% body weight; precise threshold depends on work/recovery ratio) impairs repeated anaerobic bouts, which place an increased demand on aerobic metabolism. Interactions between dehydration level, dehydration mode, testing mode, performance duration, and work/recovery ratio during repeated bouts make the dehydration threshold influencing anaerobic performance mode dependent. (Contains 3 tables.)

We analyzed the effect of an 8-week strength training (ST) program on the rate of force development (RFD) and electromyographic activity (EMG) in older women. Seventeen women (M age = 63.4 years, SD = 4.9) without previous ST experience were randomly assigned to either a control (n = 7) or training (n = 10) group. A leg-press isometric test was used for assessment. ST (three sessions/week, three sets of 10-12 repetition maximum, five different exercises) induced significant increases (p less than 0.05) on peak RFD (48.4%) and on RFD and EMG of vastus medialis at time intervals of 0-50, 0-100, 0-150, and 0-200 ms (41.1-69.2% and 43.8-64.3%, respectively). Therefore, ST resulted in favorable changes in neuromuscular responses in older women. (Contains 1 table and 1 figure.)

In the current study, we examined the relationship between serum creatine kinase (CK) activity following upper body resistance exercise with a 1- or 3-min rest between sets. Twenty men performed two sessions, each consisting of four sets with a 10-repetition maximum load. The results demonstrated significantly greater volume for the 3-min condition (M = 4,156 kg, SD = 867, for 3 min; vs. M = 3,503 kg, SD = 759, for 1 min; p less than 0.001), with no significant differences in delta CK activity between conditions (p = 0.574). Nevertheless, there was a weak correlation between the delta CK activity and total volume of exercise completed (r = 0.55 with a 1-min rest, and r =0.45 with a 3-min rest). Therefore, the volume following upper body resistance exercise correlates weakly with serum CK levels, irrespective of rest interval length between sets. (Contains 2 tables and 2 figures.)

In this study, we compared hamstring (H) and quadriceps (Q) strength changes in men and women, as well as changes in conventional and functional H:Q ratios following an identical 12-week resistance training program. An isokinetic dynamometer was used to assess 14 male and 14 female participants before and after the intervention, and conventional and functional H:Q ratios were calculated. Hamstring strength improved similarly in men and women, but improvement in quadriceps strength was significantly greater in men, while women showed only modest improvements. For the conventional and functional H:Q ratios, women showed significantly greater improvements than men. Both men and women were able to exceed the commonly recommended 0.6 conventional and 1.0 functional H:Q ratios after the 12-week lower-body resistance training program. (Contains 6 tables and 2 figures.)