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Rey, E, Costa, PB, Corredoira, FJ, and Sal de Rellan Guerra, A. Effects of age on physical match performance in professional soccer players. J Strength Cond Res XX(X): 000-000, 2019-This study aimed to evaluate the effects of age using a large-scale analysis of match physical performance in professional soccer players. A total of 10,739 individual match observations were undertaken on outfield players competing in the first and second divisions of the Spanish soccer professional leagues during the 2017-2018 season, using a computerized tracking system (TRACAB, Chyronhego, New York, USA). The players were classified into five positions and into 5 age groups (

The language employed by an individual when discussing topics of a moral nature (of the kind typically found in, e.g., social media) is revealing not only of the text affective contents itself, but also of the individual who wrote the text in the first place. Based on these observations, this work intends to illustrate how two kinds of morality-related information may be inferred from text by presenting a number of shallow and deep learning models of moral stance and moral foundations classification. In doing so, we introduce a novel corpus of texts labelled with moral foundation scores, and a novel approach to fine-grained, human-centric moral foundations classification that is, to the best of our knowledge, among the first NLP studies of this kind.

BACKGROUND: Squats are considered one of the main exercises for the lower limbs and are used in resistance training under different contexts, including rehabilitation and sports performance. OBJECTIVE: To compare the EMG activity of different muscles in back squat and lunge exercises in trained women. METHODS: Ten healthy women experienced in resistance training performed back squat and lunge exercises on a Smith machine (total work: 70% of 1RM, 1 set, 10 repetitions and 2-s/2-s of execution speed) with an interval of 20-min between exercises. Both exercises were standardized in relation to the trunk inclination and were performed with an erect trunk parallel to the cursor of the guided bar. RESULTS: The EMG activity of the vastus medialis (VM), vastus lateralis (VL), biceps femoris (BF), and gluteus maximus (GM) were analyzed. There were no significant differences in the EMG activity of the VM, VL, and BF muscles between the back squat and lunge exercises (P> 0.05); however, GM activation was greater during the lunge exercise (effect size = 1.15; P= 0.001). CONCLUSIONS: Lunges were more effective in recruiting the GM when compared to back squats. However, both exercises can be recommended when the goal is knee extensor and flexor muscle activity.

Choe, KH, Coburn, JW, Costa, PB, and Pamukoff, DN. Hip and knee kinetics during a back-squat and deadlift. J Strength Cond Res 35(5): 1364-1371, 2021-The back-squat and deadlift are performed to improve hip and knee extensor function. The purpose of this study was to compare lower extremity joint kinetics (peak net joint moments [NJMs] and positive joint work [PJW]) between the back-squat and deadlift. Twenty-eight resistance-trained subjects (17 men: 23.7 ± 4.3 years, 1.76 ± 0.09 m, 78.11 ± 10.91 kg; 11 women: 23.0 ± 1.9 years, 1.66 ± 0.06 m, 65.36 ± 7.84 kg) were recruited. One repetition maximum (1RM) testing and biomechanical analyses occurred on separate days. Three-dimensional biomechanics of the back-squat and deadlift were recorded at 70 and 85% 1RM for each exercise. The deadlift demonstrated larger hip extensor NJM than the back-squat {3.59 (95% confidence interval [CI]: 3.30-3.88) vs. 2.98 (95% CI: 2.72-3.23) Nm·kg-1, d = 0.81, p < 0.001}. However, the back-squat had a larger knee extensor NJM compared with the deadlift (2.14 [95% CI: 1.88-2.40] vs. 1.18 [95% CI: 0.99-1.37] Nm·kg-1, d = 1.44 p < 0.001). More knee PJW was performed during the back-squat compared with the deadlift (1.85 [95% CI: 1.60-2.09] vs. 0.46 [95% CI: 0.35-0.58] J·kg-1, d = 2.10, p < 0.001). However, there was more hip PJW during the deadlift compared with the back-squat (3.22 [95% CI: 2.97-3.47] vs. 2.37 [95% CI: 2.21-2.54] J·kg-1, d = 1.30, p < 0.001). Larger hip extensor NJM and PJW during the deadlift suggest that individuals targeting their hip extensors may yield greater benefit from the deadlift compared with the back-squat. However, larger knee extensor NJM and PJW during the back-squat suggest that individuals targeting their knee extensor muscles may benefit from incorporating the back-squat compared with the deadlift.

Background: The purpose of the present study was to assess the impacts of plantar-flexors and dorsi-flexors fatigue following isokinetic contractions on postural control in nine young healthy national level judo athletes. Methods: Participants were required to stand still on a force plate with opened and closed eyes in feet together (FT) and single leg (SL) stance before (PRE) and after (POST) an isokinetic fatigue protocol. Mediolateral sway (ML sway), anteroposterior sway (AP sway), and velocity sway were calculated and used to assess the postural control. Results: Velocity sway POST was significantly (P < 0.001) higher than PRE in FT stance and SL stance. Velocity sway POST was significantly higher in the SL stance than the FT stance (P = 0.01). During eyes closed, a significant interaction postural task by fatigue for all parameters was found. All parameters increased significantly after fatigue compared to PRE. After fatigue, ML sway, AP sway, and velocity sway were significantly higher for the SL stance than the FT stance. Conclusions: Ankle muscle fatigue led to reduced postural stability during different stances in young healthy judo athletes. This effect was more accentuated when vision was removed and the base of support was reduced. Alteration of postural control depended on the difficulty of the postural stance.

The aim of this study was to assess the effects of plyometric training with an agility ladder on components of physical fitness in youth soccer players. A total of twenty male under-13 soccer players were randomly assigned to a plyometric training group with an agility ladder (n=10) or a control group (n=10). Before and after training intervention linear sprint test (5 m, 10 m, 20 m), vertical jump ability (squat jump, countermovement jump and countermovement jump with arms), agility test, and slalom dribble test were assessed. The plyometric training with agility ladder was applied two times per week over six weeks. Data were analyzed using linear mixed model. The plyometric training group showed significant improvements (p0.05). The between-group analysis showed significant differences in countermovement jump with arms (p=0.03), but no significant differences (p>0.05) were found in squat jump, countermovement jump, sprint, agility test, and slalom dribble test. In conclusion, the short-term plyometric training with agility ladder seems to be ineffective and not time-efficient to improve physical fitness in youth soccer players. However, the interpretation of these results must be understood within the sample size limitations.

The purpose of this trial was to examine the effects of self-selected exercise intensities plus either whey protein or placebo supplementation on vital signs, body composition, bone mineral density, muscle strength, and mobility in older adults. A total of 101 participants aged 55 years and older (males [n = 34] and females [n = 67]) were evaluated before and after 12 weeks of self-selected, free-weight resistance exercise plus 30 min of self-paced walking three times per week. The participants were randomized into two groups: whey protein (n = 46) or placebo (n = 55). Three-way mixed factorial analyses of variance were used to test for mean differences for each variable. The 12 weeks of self-selected, self-paced exercise intensities improved resting heart rate, fat-free mass, percent body fat, handgrip strength, bench press strength, leg press strength, and all mobility measurements (p

Apoptosis is a specific form of programmed cell death that plays an important role in tissue homeostasis and also occurs during aging. In addition, exercise training may alter apoptosis-related signaling in muscles, including the cardiac muscle. However, the effects of high-intensity interval training (HIIT) on apoptosis markers in the heart have not yet been studied. Thus, the aim of the present study was to investigate the effects of HIIT on Bcl-2 and Bax expression protein levels in young and old cardiac muscles. Four and 24-month old C57BL/6J mice were used as our young adult and old groups, respectively. Animals were randomly assigned to four groups: young control (YC), young trained (YT), old control (OC), and old trained (OT). The trained groups performed HIIT 5 sessions per week for 4 weeks. RNA extraction and synthesis of cDNA was performed, and Bax and Bcl2 heart gene levels were determined by RT-PCR analysis. Training induced significant increases in Bcl-2 gene expression in YT group comparing to the YC group (p = 0.010) and in OT group comparing to OC group (p = 0.002). Training induced non-significant decrease (p > 0.05) in Bax gene expression and in Bax/Bcl-2 ratio in YT group comparing to the YC group and in OT group comparing to OC group. Aging showed no significant effect in Bcl-2 gene expression, Bax gene expression, and Bax/Bcl-2 ratio in CY group comparing to the OC group and in YT group comparing to OT group (p > 0.05). In conclusion, 4 weeks of HIIT increased Bcl-2 level for young and old heart muscles, and no effect of aging was revealed, indicating that HIIT ameliorated anti-apoptotic signaling in the young and old heart of mice.

This study evaluated the effects of age on physical and technical game performance for different positions in professional basketball players. In this cross-sectional study, a total of 25,523 individual match observations were undertaken on players from the 2018-19 NBA season. The players were classified into four age groups (19-22 years, 23-25 years, 26-29 years, and 30-42 years). Differences in physical and technical match performance were analysed for the following variables: distance covered, average speed, minutes played, points scored and playing efficiency. The results showed that players older than 30 covered shorter distance and had lower average speed than younger players, that guards and forwards older than 26 played more minutes per game than younger ones, and that guards older than 26 scored more points and were more efficient than younger one, while centres age 23-25 scored more points per games than centres older than 30. In conclusion, physical performance declined with age, and while playing time and technical performance generally remained stable or increased, especially for guards. However, there was some evidence of decline for centres.

The aim of this study was to examine the effects of coordination training using an agility ladder compared with a control group on physical fitness and technical performance in youth soccer players. Eighteen male youth soccer players (age: 12.2 ± 0.4 years; body height: 158.3 ± 10.8 cm; body mass: 45.0 ± 8.0 kg) were randomly assigned to an agility ladder group (n = 10) or a control group (n = 8). The intervention program was carried out three times a week over six weeks. Before and after the training period, the 10 m sprint, 20 m sprint, dribbling speed test, agility test, and slalom dribbling test performances were assessed. Within-group analysis showed significant improvements (p < 0.005) in 10 m and 20 m sprint performance from the pre- to the post-test for the agility ladder group (-2.39% and -2.10%) and the control group (-2.54% and -1.44%). No significant differences (p > 0.005) were found from the pre- to the post-test in the dribbling speed test, agility test, slalom dribbling test, and skill index. In the between-group analysis, there were no differences between the agility ladder group and the control group in any variable. In conclusion, the findings of this study suggest coordination training with an agility ladder does not seem to be effective to improve physical fitness and dribbling. Therefore, this information could be beneficial to players and coaches for programming tasks during soccer training sessions.

The aim of this study was to analyse the effect of the score-line on the internal and external load in soccer small-sided games (SSGs). Thirty male semi-professional soccer players particip...

The aim of this study was to compare the effectiveness of acute of contract–relax (CR) and contract–relax–antagonist–contraction (CRAC) targeting the quadriceps, hamstrings, anterior tibialis, and calf muscles and warm-up without stretching on medio-lateral (ML) and antero-posterior (AP) dynamic balance control in healthy young men applied by a physiotherapist in comparison to a control intervention without stretching. Twenty healthy young men between the age of 18 and 25 performed three interventions in randomized days after standard warm-up: CR intervention, CRAC intervention, and control intervention. ML and AP dynamic balance control was carried out before (Pre) and immediately after (Post) each intervention. Antero-posterior sway (AP sway) and medio-lateral sway (ML sway) under vision and no vision condition were analyzed by posturography. CRAC intervention improved significantly ML dynamic balance control by decreasing ML sway (vision, p = 0.006 and no vision, p

The aim of this study was to determine the effects of 2 different repeated-sprint ability (RSA) training frequencies (2 RSA sessions per week [RSA2D] or 1 RSA session [RSA1D]) under volume-equated conditions on sprint and RSA performance in under-15 (U15) soccer players. Twenty-seven youth male soccer players (age: 12.29±0.47 years; height: 158.35±10.86 cm; weight: 45.08±8.05 kg) were randomly assigned to RSA2D (n=14) or RSA1D (n=13) groups. The players performed the same RSA training for 6 weeks, and only the training frequency differed between the groups. Before and after the training period, 5 m sprint, 10 m sprint, 20 m sprint and the RSA test were assessed. No significant time × group interactions were observed (p>0.05). Within-group analysis showed significant improvements in 20 m sprint (p=0.046, partial eta squared [ηp2 ] = 0.150, large) and RSA average time (p=0.001, ηp2 =0.438, large), fastest time (p=0.012, ηp2 =0.229, large), and total time (p=0.001, ηp2 =0.438, large) from pre-test to post-test in RSA1D and RSA2D groups. However, no significant pre-post changes (p>0.05) were found in 5 m and 10 m sprint tests. In the between-group analysis, there were no significant differences between RSA1D and RSA2D groups in any variable. In conclusion, the current findings suggest that 6 weeks of RSA training 1 or 2 times per week in addition to typical soccer training produced significant and similar improvements in sprint and RSA performances. This information could be useful for coaches when planning training sessions during congested fixtures of soccer competitions or in periods when the emphasis should be placed on other physical qualities.

PURPOSE Obesity influences gait and muscle function, which may contribute to knee osteoarthritis. This study aimed 1) to compare gait biomechanics and quadriceps function between individuals with and without obesity and 2) to examine the association between quadriceps function and gait biomechanics. METHODS Forty-eight individuals with and 48 without obesity participated and were matched on age and sex. Gait biomechanics at standardized and self-selected speeds were used to assess peak vertical ground reaction force (vGRF), vertical loading rate (vLR), internal knee extension moment (KEM), peak knee flexion angle (KFA), knee flexion excursion (KFE), and knee joint stiffness. Quadriceps function was assessed using peak isometric strength (peak torque), early (RTD100) and late (RTD200) rate of torque development (RTD), and vastus lateralis cross-sectional area (CSA) and echo intensity (EI). RESULTS When normalized to fat-free mass, individuals with obesity had lower RTD100 (P = 0.04) and RTD200 (P = 0.02) but higher vastus lateralis CSA (P < 0.01) and EI (P < 0.01) compared with normal weight controls. The group-speed interaction was significant for normalized vGRF (P < 0.01), normalized vLR (P = 0.02), normalized KEM (P = 0.03), and normalized knee joint stiffness (P = 0.02). Post hoc analyses indicate a smaller normalized vGRF and normalized KEM, and lower knee joint stiffness in individuals with obesity compared with normal weight controls at self-selected speed. There were main effects of speed for all kinematic and kinetic variables, and body mass index group for all absolute kinetic variables as well as normalized vGRF (all P < 0.001). A lower vastus lateralis EI (P = 0.04) and greater RTD100 (P < 0.01) were associated with a larger KEM in individuals with obesity. CONCLUSION Individuals with obesity have quadriceps dysfunction that is weakly associated with KEM during walking. Exercise interventions that improve quadriceps function may improve walking mechanics.

Bagley, JR, Burghardt, KJ, McManus, R, Howlett, B, Costa, PB, Coburn, JW, Arevalo, JA, Malek, MH, and Galpin, AJ. Epigenetic responses to acute resistance exercise in trained vs. sedentary men. J Strength Cond Res 34(6): 1574-1580, 2020-Acute resistance exercise (RE) alters DNA methylation, an epigenetic process that influences gene expression and regulates skeletal muscle adaptation. This aspect of cellular remodeling is poorly understood, especially in resistance-trained (RT) individuals. The study purpose was to examine DNA methylation in response to acute RE in RT and sedentary (SED) young men, specifically targeting genes responsible for metabolic, inflammatory, and hypertrophic muscle adaptations. Vastus lateralis biopsies were performed before (baseline), 30 minutes after, and 4 hours after an acute RE bout (3 × 10 repetitions at 70% 1 repetition maximum [1RM] leg press and leg extension) in 11 RT (mean ± SEM: age = 26.1 ± 1.0 years; body mass = 84.3 ± 0.2 kg; leg press 1RM = 412.6 ± 25.9 kg) and 8 SED (age = 22.9 ± 1.1 years; body mass = 75.6 ± 0.3 kg; leg press 1RM = 164.8 ± 22.5 kg) men. DNA methylation was analyzed through methylation sensitive high-resolution melting using real-time polymerase chain reaction. Separate 2 (group) × 3 (time) repeated-measures analyses of variance and analyses of covariance were performed to examine changes in DNA methylation for each target gene. Results showed that acute RE (a) hypomethylated LINE-1 (measure of global methylation) in RT but not SED, (b) hypermethylated metabolic genes (GPAM and SREBF2) in RT, while lowering SREBF2 methylation in SED, and (c) did not affect methylation of genes associated with inflammation (IL-6 and TNF-α) or hypertrophy (mTOR and AKT1). However, basal IL-6 and TNF-α were lower in SED compared with RT. These findings indicate the same RE stimulus can illicit different epigenetic responses in RT vs. SED men and provides a molecular mechanism underpinning the need for differential training stimuli based on subject training backgrounds.

Madoni, SN, Costa, PB, Coburn, JW, and Galpin, AJ. Effects of foam rolling on range of motion, peak torque, muscle activation, and the hamstrings-to-quadriceps strength ratios. J Strength Cond Res 32(7): 1821-1830, 2018-To examine the effects of foam rolling (FR) on range of motion (ROM), peak torque (PT), hamstrings-to-quadriceps (H:Q) ratios, and muscle activation. Twenty-two recreationally active women (mean age ± SD = 21.55 ± 1.82 years, 161.91 ± 6.58 cm, 61.47 ± 10.54 kg) volunteered for this study. Participants performed pre- and posttests analyzing PT and surface electromyography (EMG) of their dominant limb, completing maximal knee extension and flexion at 3 different velocities. Participants foam rolled the hamstrings muscles or sat for the control condition between the pre- and posttests. Hamstrings ROM increased in the FR condition from (mean ± SE) 123.23 ± 3.49 to 126.41 ± 3.62° (p0.001) and decreased in the control condition from 118.82 ± 4.25 to 117.95 ± 4.29° (p = 0.013). Concentric hamstrings PT and conventional H:Q ratios decreased after both conditions, with smaller decreases after FR (p ≤ 0.05). No significant changes were found for eccentric hamstrings PT, eccentric hamstrings EMG, or functional H:Q ratios (p0.05). Foam rolling resulted in greater changes in hamstrings ROM without creating a deficit in PT or muscle activation when compared with the control group. When compared with other methods of stretching, FR may be beneficial in increasing ROM without decreasing functional H:Q ratios.

Aims The aim of this study was to examine the association between muscle function, and body composition, vitamin D status, and blood glucose in post-menopausal women with type 2 diabetes (T2D). Methods Forty post-menopausal women (62.48 ± 7.67 years; 154.6 ± 5.11 cm; 73.93 ± 15.43 kg; 31.13 ± 5.82 BMI kg/m2) with a diagnosis of T2D participated in this cross-sectional study. The patients performed fasting blood sample exams, anthropometrics assessments, body composition, and clinical exams. Subjects performed physical tests including handgrip, timed up and go, 30-s chair stand, arm curl, and sit-to-stand. The correlation between the parameters of physical tests, age, body composition, vitamin D, and blood glucose was assessed by Pearson correlation. Results The results showed there were significant correlations between blood glucose and relative strength (R = −0.398, p = 0.011), arm curl test (R = −0.367 and p = 0.020), and hip flexion (R = 0.427, p = 0.006). Conclusions These findings are important because they highlight the importance of resistance training in individuals with T2D and the relationship with a fat increase during a dicrease process. Furthermore, the concentration of serum glucose might be associated with decreases in muscle strength and muscle function in older adults. Thus, T2D patients should be involved with strength training to improve the strength and the muscle hypertrophy.

Background: A new fitness trend incorporates stability exercises that challenges trunk muscles and introduces crawling as an exercise, but has yet to be investigated for muscle activity. Purpose: To compare the effects of static (STA), stationary (STN), and traveling (TRV) trunk exercises on muscle activation of the rectus abdominis, rectus femoris, external oblique, and erector spinae using surface electromyography (EMG). Methods: Seventeen recreationally active women (mean age ± SD = 22.4 ± 2.4 years, body mass 62.9 ± 6.9 kg, height 165.1 ± 5.8 cm) and twenty-three men (23.6 ±3.9 years, 83.2 ±17.1 kg, 177.1 ± 9.1 cm) volunteered to participate in this study. Subjects performed maximal voluntary contractions for normalization of each muscle’s EMG activity. They then performed the three exercises in random order for thirty seconds each with a two-minute rest in between. Results: For the rectus abdominis, STA was significantly lower than STN (P = 0.003) and TRV (P = 0.001). For the external oblique, STA was significantly lower than STN (P = 0.001) and TRV (P = 0.001) and STN was significantly greater than TRV (P = 0.009). For the erector spinae and rectus femoris, STA was significantly lower than STN (P = 0.001) and TRV (P = 0.001) Conclusions: There was greater muscle activation in all muscles tested in the stationary and traveling exercises versus the static. Strength and conditioning coaches and allied health professionals could potentially use stationary and traveling forms of trunk stabilization exercises as a viable strategy to increase muscle activation.

Women and men present different metabolic responses to exercise, yet whether this phenomenon results from differences in fiber type (FT) composition or other sex-specific factors remains unclear. Therefore, our aim was to examine the effects of sex and FT independently on AMP-activated protein kinase (AMPK), acetyl-CoA carboxylase (ACC), Tre-2/BUB2/CDC1 domain family (TBC1D)1, and TBC1D4 in response to acute exercise. Segregated pools of myosin heavy chain (MHC) I and MHC IIa fibers were prepared from vastus lateralis biopsies of young trained men and women at rest and during recovery (0 min, 45 min, 90 min, or 180 min) from high-intensity interval exercise (6 × 1.5 min at 95% maximum oxygen uptake). In resting MHC I vs. IIa fibers, AMPKα2, AMPKγ3, and TBC1D1 were higher and TBC1D4 expression was lower in both sexes, along with higher phospho (p)-TBC1D1Ser660and lower p-TBC1D4Thr642. Women expressed higher ACC than men in MHC IIa fibers and higher AMPKβ1, AMPKβ2, TBC1D1, and TBC1D4 in both FTs. Immediately after exercise, p-AMPKαThr172increased only in MHC IIa fibers, whereas p-ACCSer221increased in both FTs, with no change in p-TBC1D1Ser660or p-TBC1D4Thr642. During recovery, delayed responses were observed for p-AMPKαThr172in MHC I (45 min), p-TBC1D4Thr642in both FTs (45 min), and p-TBC1D1Ser660(180 min). FT-specific phosphorylation responses to exercise were similar between men and women. Data indicate that sex and FT independently influence expression of AMPK and its substrates. Thus failing to account for sex or FT may reduce accuracy and precision of metabolic protein measurements and conceal key findings.NEW & NOTEWORTHY This investigation is the first to compare muscle fiber type (FT)-specific analysis of proteins between the sexes, providing comprehensive data on AMP-activated protein kinase (AMPK), acetyl-CoA carboxylase (ACC), Tre-2/BUB2/CDC1 domain family (TBC1D)1, and TBC1D4 before and in the hours following high-intensity interval exercise (HIIT). Expression and phosphorylation of specific AMPK isoforms, ACC, TBC1D1, and TBC1D4 were shown to be FT dependent, sex dependent, or both, and TBC1D1 showed an unexpected delay in FT-dependent phosphorylation in the time period following HIIT.

In Natural Language Generation systems, personalization strategies - i.e, the use of information about a target author to generate text that (more) closely resembles human-produced language - have long been applied to improve results. The present work addresses one such strategy - namely, the use of Big Five personality information about the target author - applied to the case of abstractive text summarization using neural sequence-to-sequence models. Initial results suggest that having access to personality information does lead to more accurate (or human-like) text summaries, and paves the way for more robust systems of this kind.

The aim of this study was to examine changes in muscle contractile properties across a microcycle of training in professional soccer players during the in-season period. Nineteen professional soccer players were assessed with tensiomyography (TMG) on the biceps femoris and rectus femoris before and after 5 training sessions of an in-season microcycle. Training load was quantified during each training session. Significant differences were observed in training load variables across different training sessions, with the last training session prior to match day showing the lowest values for all training load variables. Significant pre- to post-session increases were observed in muscle stiffness of the rectus femoris and biceps femoris during the first four training sessions (effect size range, 0.5 to 0.9). However, no significant differences were observed in muscle contraction time and contraction velocity from pre- to post-session. In addition, repeated measures correlation analysis revealed significant relationships between absolute change in muscle stiffness of the rectus femoris and training duration, high-speed distance covered during training, and training average distance. The current study shows that players are physically taxed on their muscular stiffness by the training load. Post-session muscular stiffness assessment should be recommended to determine neuromuscular status and readiness in professional soccer players during the competitive season.

The present study compared the acute effect of different combinations of resistance training (RT) and static stretching (SS) on the heart rate (HR), rate pressure product (RPP) and oxygen saturation (SpO 2 ) of participants. This is a cross-over methodological design carried out in five visits on non-consecutive days, which always occurred at the same time of day. Twelve trained young men were randomly divided, using counterbalanced and alternate assignments, into three experimental situations: a) horizontal abduction of the shoulder, knee flexion and hip abduction before the bench press and leg extension machine, respectively (SS + RT); b) bench press and leg extension machine before horizontal abduction of shoulder, knee flexion and hip abduction, respectively (RT + SS); c) bench press and leg extension machine, exclusively (RT). Analysis of variance (ANOVA) with repeated measures showed significant differences in the SS+RT group when the variables were compared at rest (pre) and immediately after the exercises (post): HRpre vs. HRpost (p = 0.000) and RPPpre vs. RPPpost (p = 0.000). In the intergroup comparisons, significant differences were detected between the SS+RT and RT+SS experimental situations exclusively during the post period for the RPP (p = 0.041) and SpO 2 variables (p = 0.002). The combined use of SS and RT significantly changed the intragroup cardiovascular responses by increasing the HR and RPP and decreasing the SpO 2 . However, the values were lower in the intergroup comparisons when the stretching exercises were performed both before and after RT, although no significant differences were found from a cardiovascular safety point of view.

Summary Objective Muscle stretching is plenty used prior to training and competition. Considering the importance of balance control in performance, muscle stretching is expected to have positive effects on balance. However, there is a lack of studies investigating the effects of contract-relax proprioceptive neuromuscular facilitation (CR PNF) stretching on balance control. The purpose of this study was to investigate the effects of CR PNF stretching on static postural balance. Methods Fourteen subjects were tested before and after a 5-minute cycle warm-up followed by 10 minutes of CR PNF stretching (stretching condition) and the same cycle warm-up with 10-minute rest periods (control condition). The four muscle groups stretched were the quadriceps, hamstrings, anterior tibialis, and calf muscles of both legs in an alternating manner. Postural balance was assessed in a bipedal static stance before and after each condition with eyes opened (EO) and eyes closed (EC). Results No significant interactions for any postural parameters. However, there was a significant main effect of condition for sway area (P 0.05). Conclusion It appears that the stretching and control conditions impaired static balance control by increasing postural sway. CR PNF stretching was unable to compensate for the warm-up and its effects of induced alteration in postural balance.

Ultrasound muscle images have been extensively used as tools for investigating, diagnosing and monitoring thigh muscles. However, there is a lack of information examining ultrasound reliability of quadriceps and hamstrings images for research and clinical use. Objectives: To determine the reliability of muscle thickness (MT), echo intensity (EI) and cross sectional area (CSA) of quadriceps and hamstrings muscle groups. Methods: Single transverse images of the rectus femoris (RF), vastus intermedius (VI), vastus medialis (VM), vastus lateralis (VL), biceps femoris long head (BFlh), semitendinosus (ST), and semimembranosus (SM) muscles were scanned in the right and left legs of ten healthy collegiate men (age 23.4 ± 2.2 yrs, mass 71.7 ± 11.7 kg, height 1.73 ± 0.06 m) between two sessions with one day interval. Intraclass correlation coefficients (ICCs), standard error of measurement (SEM), and minimum difference to be considered “real” (MD) were measured for MT, EI, and CSA. Results: A range of 0.97-0.99, 0.83-0.88, and 0.86-0.97 (ICC); 0.72-1.38, 2.73-3.41, and 0.36-1.04 (SEM); and 2.01-3.82, 7.56-9.46, and 0.99-2.89 (MD) were found for quadriceps muscles, and 0.93-0.99, 0.74-0.90, and 0.89-0.96 (ICC); 0.73-1.94, 3.29-4.98, and 0.69-1.08 (SEM); and 2.03-5.38, 9.13-13.81, and 1.91-2.98 (MD) were found for hamstrings muscles. Conclusions: These results suggest that ultrasound imaging of both quadriceps and hamstrings muscle architecture is a reliable technique for assessing thigh musculoskeletal tissue. The anatomical sites, as well as ultrasound adjustments, images, and results utilized here may assist future researchers and clinicians as reference tools when measuring quadriceps and hamstrings musculature.

Monteiro, ER, Costa, PB, Corrêa Neto, VG, Hoogenboom, BJ, Steele, J, and da Silva Novaes, J. Posterior thigh foam rolling increases knee extension fatigue and passive shoulder range-of-motion. J Strength Cond Res 33(4): 987-994, 2019-The purpose of this study was to analyze the acute effects of different foam rolling (FR) volumes on knee extensors fatigue and shoulder passive range-of-motion (PROM). Twelve recreationally active women were recruited for participation in 2 experiments separated by 3 weeks, and the same subjects performed all procedures in each experiment. In experiment 1, subjects performed 3 sets of knee extensions using a predetermined 10 repetition maximum load to momentary concentric failure: control condition (CG) with passive rest and 2 FR conditions for the hamstrings using 2 volumes (60 and 120 seconds; FR60 and FR120, respectively). Experiment 2 consisted of 2 shoulder flexion and extension baseline PROM tests. Following baseline measures, subjects performed a single 60-second bout of FR on the hamstrings. Outcome PROM measures were measured through manual goniometry immediately (post-0), 10 minutes (post-10), 20 minutes (post-20), 30 minutes (post-30), 24 hours (post-24), and 48 hours (post-48) after the intervention to assess the effects on PROM over an extended period. Fatigue index indicated significantly greater fatigue resistance for CG when compared with FR60 (p = 0.035; [INCREMENT]% = 6.49) and FR120 (p = 0.002; [INCREMENT]% = 9.27), and there were no significant differences between FR60 and FR120 (p = 0.513; [INCREMENT]% = 2.78). Shoulder flexion PROM increased in post-0 as compared to baseline 1 (p = 0.002; d = 1.58), baseline 2 (p < 0.001; d = 1.92), and baseline higher measurement (p < 0.001; d = 1.59) and remained increased for post-10 as compared to baseline 2 (p = 0.017; d = 1.55). Shoulder extension PROM increased in post-0 as compared to baseline 1 (p < 0.001; d = 2.61), baseline 2 (p < 0.001; d = 2.83), and baseline higher measurement (p < 0.001; d = 2.59) and remained increased for post-10 as compared to baseline 1 (p < 0.001; d = 1.93), baseline 2 (p < 0.001; d = 2.16), and baseline higher measurement (p < 0.001; d = 1.91) and post-20 as compared to baseline 1 (p = 0.008; d = 1.58), baseline 2 (p = 0.001; d = 1.85), and baseline higher measurement (p = 0.011; d = 1.55). Foam rolling volumes equal to or greater than 60 seconds are detrimental to the ability to continually produce force in the lower extremity and should not be applied to the hamstrings muscle group between sets of knee extensions. PROM results indicate that FR applied to the hamstrings demonstrates an increase in both shoulder flexion and extension PROM. This work may have important clinical (rehabilitation) implications, as it demonstrates global effects of FR on functional outcomes.