Effects of gender, activity type, class location and class composition on physical activity levels experienced during physical education classes in British secondary schools: a pilot cross-sectional study.

BACKGROUND: Pupils in secondary schools do not meet the targets for physical activity levels during physical education (PE) sessions, and there is a lack of data on the vigorous physical activity domain (VPA) in PE known to be positively associated with cardio metabolic health While PE session intensity depends on a variety of factors, the large majority of studies investigating these factors have not taken into account the nested structure of this type of data set. Therefore, the aim of this study was to investigate the relationship between various factors (gender, activity type, class location and class composition) and various activity levels during PE classes in secondary schools, using a multi-level statistical approach. METHODS: Year eight (12-13 years old) adolescents (201 boys and 106 girls) from six schools were fitted with accelerometers during one PE session each, to determine the percentage (%) of the PE session time spent in sedentary (SPA), light (LPA), moderate (MPA), vigorous (VPA) and moderate-to-vigorous (MVPA) intensity levels. Two- and three-level (pupils, n = 307; classes, n = 13, schools, n = 6) mixed-effect models were used to assess the relationship between accelerometer-measured physical activity levels (% of class time spent in various activity levels) and gender, activity type, class location and composition. RESULTS: Participants engaged in MVPA and VPA for 30.7 ± 1.2% and 11.5 ± 0.8% of PE classes, respectively. Overall, no significant association between gender or class composition and PA was shown. A significant relationship between activity type and PA was observed, with Artistic classes significantly less active than Fitness classes for VPA (5.4 ± 4.5 vs. 12.5 ± 7.1%, p = 0.043, d:1.19). We also found a significant association between class location and PA, with significantly less time spent in SPA (24.8 ± 4.8% vs. 30.0 ± 3.4%, p = 0.042, d:0.77) and significantly more time spent in VPA (12.4 ± 3.7% vs. 7.6 ± 2.0%, p = 0.022, d:1.93) and MVPA (32.3 ± 6.7% vs.24.8 ± 3.8%, p = 0.024, d:1.33) in outdoors vs. indoors classes. CONCLUSIONS: The results suggest that class location and activity type could be associated with the intensity of PA in PE. It is essential to take into account the clustered nature of this type of data in similar studies if the sample size allows it.

Changes in Torque-Angle Profiles of the Hamstrings and Hamstrings-to-Quadriceps Ratio After Two Hamstring Strengthening Exercise Interventions in Female Hockey Players.

Delextrat, A, Bateman, J, Ross, C, Harman, J, Davis, L, Vanrenterghem, J, and Cohen, DD. Changes in torque-angle profiles of the hamstrings and hamstrings-to-quadriceps ratio after two hamstring strengthening exercise interventions in female hockey players. J Strength Cond Res 34(2): 396-405, 2020-The aim of this study was to compare the effects of 2 hamstring strengthening interventions (Nordic hamstrings [NHE] vs. eccentric leg curl [ELC]) on the hamstring torque-angle profiles and functional hamstrings-to-quadriceps ratio (Hecc:Qcon) in female hockey players. Female university-level players were randomly allocated to an NHE group (n = 9, 19.7 ± 1.4 years; 168.4 ± 4.4 cm; 66.2 ± 7.2 kg, 26.0 ± 4.4%), an ELC group (n = 8, 19.5 ± 1.0 years; 168.1 ± 3.4 cm; 66.7 ± 4.5 kg, 24.8 ± 3.5%), or a control (C) group (n = 8, 19.6 ± 1.4 years; 169.9 ± 7.5 cm; 70.7 ± 13.0 kg, 25.9 ± 5.2%). They performed baseline isokinetic concentric strength tests of the quadriceps (Qcon) and eccentric strength of the hamstrings (Hecc) at 120°·s, followed by a 6-week intervention with exercises (NHE or ELC) performed 3 times weekly, before post-tests. Analyses of variance with repeated measures were used to assess the effects of knee position angle (from 90° of knee flexion to 10° close to extension), group, and time on Qcon, Hecc, and Hecc:Qcon. There were no interactions between independent variables. Significant increases in Hecc and Hecc:Qcon were shown after NHE (+29.9 and +27.8%) and ELC (+30.5 and +38.3%) in the nondominant leg only. Furthermore, significant shifts in the hamstring eccentric angle of peak torque toward a longer muscle length were shown in both legs (14.3-28.6%). These findings suggest that NHE and ELC both resulted in significant improvements in peak and muscle-length-specific neuromuscular risk factors in the nondominant (ND) limb, thereby reducing interlimb peak strength asymmetries. Strength and conditioning specialists could therefore use both the NHE and ELC exercises in female hockey players.

Cognitive Performance, Quality and Quantity of Movement Reflect Psychological Symptoms in Adolescents.

The presentation of unhealthy psychological symptoms are rising sharply in adolescents. Detrimental lifestyle behaviours are proposed as both possible causes and consequences. This study set out to compare selected measures of quality and quantity of movement between adolescents with and without unhealthy psychological symptoms. Using a cross sectional design, 96 participants completed the study from a whole year group of 166, age (13.36 ± 0.48) male 50.6% from a secondary school in Oxfordshire, England as a part of a larger study (EPIC) between January and April 2018. Measures were taken of quality and quantity of movement: reaction/movement time, gait pattern & physical activity, alongside psychological symptoms. Differences in movement behaviour in relation to psychological symptom and emotional problem presentation were determined using ANOVA. In the event of a significant result for the main factor of each parameter, a Bonferroni -corrected post hoc test was conducted to show the difference between categories in each group. Results for both unhealthy psychological symptoms and emotional problems were grouped into four categories ('Close to average', 'slightly raised', 'high' and 'very high'). Early adolescents with very high unhealthy psychological symptoms had 16.79% slower reaction times (p = 0.003, ηp2 = 0.170), 13.43% smaller walk ratio (p = 0.007, ηp2 = 0.152), 7.13% faster cadence (p = 0.005, ηp2 = 0.149), 6.95% less step time (p = 0.007, ηp2 = 0.153) and 1.4% less vigorous physical activity (p = 0.04, ηp2 = 0.102) than children with close to average psychological symptoms. Early adolescents with very high emotional problems had 12.25% slower reaction times (p = 0.05, ηp2 = 0.081), 10.61% smaller walk ratio (p = 0.02, ηp2 = 0.108), 6.03% faster cadence (p = 0.01, ηp2 = 0.134), 6.07% shorter step time (p = 0.007, ηp2 = 0.141) and 1.78% less vigorous physical activity (p = 0.009, ηp2 = 0.136) than children with close to average emotional problems. Different movement quality and quantity of was present in adolescents with unhealthy psychological symptoms and emotional problems. We propose movement may be used to both monitor symptoms, and as a novel therapeutic behavioural approach. Further studies are required to confirm our findings.

Dribble Deficit: A novel method to measure dribbling speed independent of sprinting speed in basketball players.

Basketball tests assessing dribbling speed predicated on total performance times are influenced by sprinting speed. This study examines an approach termed Dribble Deficit to counter this limitation by examining the relationships between sprinting and dribbling speed during linear and change-of-direction (COD) tasks measured using total performance time and Dribble Deficit. Ten semi-professional basketball players completed linear sprints and COD sprints with and without dribbling. Dribble Deficit was calculated as the difference between the best time for each dribbling trial and corresponding non-dribbling trial for linear and COD sprints. Large to very large significant relationships (P < 0.05) were evident between linear sprint and dribble times (R = 0.64-0.77, R2 = 0.41-0.59), and between COD sprint and dribble times (R = 0.88, R2 = 0.77). Conversely, trivial-small relationships were evident between linear sprint time and linear Dribble Deficit (R = 0.01-0.15, R2 = 0.00-0.02). A non-significant, moderate, negative relationship was observed between COD sprint time and COD Dribble Deficit (R = -0.45, R2 = 0.20). These findings indicate Dribble Deficit provides a more isolated measure of dribbling speed than tests using total performance times. Basketball practitioners may use Dribble Deficit to measure dribbling speed independent of sprint speed in test batteries.

Decrements in knee extensor and flexor strength are associated with performance fatigue during simulated basketball game-play in adolescent, male players.

This study quantified lower-limb strength decrements and assessed the relationships between strength decrements and performance fatigue during simulated basketball. Ten adolescent, male basketball players completed a circuit-based, basketball simulation. Sprint and jump performance were assessed during each circuit, with knee flexion and extension peak concentric torques measured at baseline, half-time, and full-time. Decrement scores were calculated for all measures. Mean knee flexor strength decrement was significantly (P < 0.05) related to sprint fatigue in the first half (R = 0.65), with dominant knee flexor strength (R = 0.67) and dominant flexor:extensor strength ratio (R = 0.77) decrement significantly (P < 0.05) associated with sprint decrement across the entire game. Mean knee extensor strength (R = 0.71), dominant knee flexor strength (R = 0.80), non-dominant knee flexor strength (R = 0.75), mean knee flexor strength (R = 0.81), non-dominant flexor:extensor strength ratio (R = 0.71), and mean flexor:extensor strength ratio (R = 0.70) decrement measures significantly (P < 0.05) influenced jump fatigue during the entire game. Lower-limb strength decrements may exert an important influence on performance fatigue during basketball activity in adolescent, male players. Consequently, training plans should aim to mitigate lower-limb fatigue to optimise sprint and jump performance during game-play.

Effects of Three-Day Serial Sodium Bicarbonate Loading on Performance and Physiological Parameters During a Simulated Basketball Test in Female University Players.

The aim of this study was to investigate the effect of 3-day serial sodium bicarbonate ingestion on repeated sprint and jump performance. Fifteen female university basketball players (23.3 ± 3.4 years; 173.1 ± 5.8 cm; 65.8 ± 6.3 kg; 23.6 ± 4.9% body fat) ingested 0.4 g/kg body mass of sodium bicarbonate or placebo for 3 days (split in three equal daily doses), before completing a simulated basketball exercise. Sprint and circuit times, jump heights, performance decrements, and gastrointestinal side effects were recorded during the test, and blood lactate concentration was measured pre- and posttest. Sodium bicarbonate supplementation led to significant decreases in mean sprint times (1.34 ± 0.23 vs. 1.70 ± 0.41 s, p = .008, 95% confidence intervals [-0.54, -0.10 s]) and mean circuit times (30.6 ± 2.0 vs. 31.3 ± 2.0 s, p = .044) and significantly greater mean jump height (26.8 [range 25.2-34.2] vs. 26.0 [range 25.6-33.6] cm, p = .013) compared with placebo. Performance decrement was significantly less for sprints with sodium bicarbonate compared with placebo (9.9 [range 3.4-37.0]% vs. 24.7 [range 4.1-61.3]%, p = .013), but not different for jumps (13.1 ± 4.5% vs. 12.5 ± 3.1%, p = .321) between conditions. No differences in gastrointestinal side effects were noted between conditions. Significantly greater postexercise blood lactate concentrations were measured in the sodium bicarbonate condition compared with the placebo condition (8.2 ± 2.8 vs. 6.6 ± 2.4 mmol/L, p = .010). This study is the first to show that serial loading of sodium bicarbonate is effective for basketball players to improve repeated sprint and jump performance during competition, or withstand greater training load during practice sessions without any gastrointestinal side effects.

Effects of Small-Sided Games and High-Intensity Interval Training on Aerobic and Repeated Sprint Performance and Peripheral Muscle Oxygenation Changes in Elite Junior Basketball Players.

Delextrat, A, Gruet, M, and Bieuzen, F. Effects of small-sided games and high-intensity interval training on aerobic and repeated sprint performance and peripheral muscle oxygenation changes in elite junior basketball players. J Strength Cond Res 32(7): 1882-1891, 2018-The aim of the current study was to compare the effects of 6 weeks of small-sided game (SSG) and high-intensity interval training (HIIT) on aerobic fitness and muscle oxygenation during a repeated sprint (RS) sequence in elite male junior basketball players. Twenty participants (14.3 ± 0.5 years; 176.8 ± 12.5 cm; 74.5 ± 9.8 kg) performed pre- and post-tests interspersed by 6 weeks of SSG or HIIT training. Testing sessions consisted of the 30-15 intermittent fitness test and an RS sequence (2 bouts of 15 seconds). During RS, muscle oxygenation parameters (tissue saturation index [TSI, %], postsprint muscle reoxygenation rate) were measured using near-infrared spectroscopy. The results showed that both training interventions similarly improved maximal aerobic speed (VIFT, 3.4 and 4.1%, respectively, for HIIT and SSG, P < 0.05) as well as RS ability (smaller percentage decrement by 62.5 and 21.6%, respectively, for HIIT and SSG, P < 0.05). Both training interventions also resulted in a greater ΔTSI during the second sprint (47.8-114%, P < 0.05) and significant improvements in postsprint reoxygenation after both sprints (+23.0 to +107.7%). Finally, the variation in muscle reoxygenation after sprint 1 was significantly associated with improvements in aerobic (ΔVIFT, r = 0.61, P = 0.008) and anaerobic (Δ% Dec during RS, r = -0.487, P = 0.028) performances. The current study has observed that SSG and HIIT resulted in similar improvements in aerobic and anaerobic variables and a better muscle oxygenation capacity during RS. Coaches should be aware that both trainings are applicable methodologies to improve in-season aerobic and anaerobic fitness capacities in junior basketball players.

Influence of different types of compression garments on exercise-induced muscle damage markers after a soccer match.

There is not enough evidence of positive effects of compression therapy on the recovery of soccer players after matches. Therefore, the objective was to evaluate the influence of different types of compression garments in reducing exercise-induced muscle damage (EIMD) during recovery after a friendly soccer match. Eighteen semi-professional soccer players (24 ± 4.07 years, 177 ± 5 cm; 71.8 ± 6.28 kg and 22.73 ± 1.81 BMI) participated in this study. A two-stage crossover design was chosen. Participants acted as controls in one match and were assigned to an experimental group (compression stockings group, full-leg compression group, shorts group) in the other match. Participants in experimental groups played the match wearing the assigned compression garments, which were also worn in the 3 days post-match, for 7 h each day. Results showed a positive, but not significant, effect of compression garments on attenuating EIMD biomarkers response, and inflammatory and perceptual responses suggest that compression may improve physiological and psychological recovery.

No Dose-Response Effect of Carbohydrate Mouth Rinse Concentration on 5-km Running Performance in Recreational Athletes.

Clarke, ND, Thomas, JR, Kagka, M, Ramsbottom, R, and Delextrat, A. No dose-response effect of carbohydrate mouth rinse concentration on 5-km running performance in recreational athletes. J Strength Cond Res 31(3): 715-720, 2017-Oral carbohydrate rinsing has been demonstrated to provide beneficial effects on exercise performance of durations of up to 1 hour, albeit predominately in a laboratory setting. The aim of the present study was to investigate the effects of different concentrations of carbohydrate solution mouth rinse on 5-km running performance. Fifteen healthy men (n = 9; mean ± SD age; 42 ± 10 years; height, 177.6 ± 6.1 cm; body mass, 73.9 ± 8.9 kg) and women (n = 6; mean ± SD age, 43 ± 9 years; height, 166.5 ± 4.1 cm; body mass, 65.7 ± 6.8 kg) performed a 5-km running time trial on a track on 4 separate occasions. Immediately before starting the time trial and then after each 1 km, subjects rinsed 25 ml of 0, 3, 6, or 12% maltodextrin for 10 seconds. Mouth rinsing with 0, 3, 6, or 12% maltodextrin did not have a significant effect on the time to complete the time trial (0%, 26:34 ± 4:07 minutes:seconds; 3%, 27:17 ± 4:33 minutes:seconds; 6%, 27:05 ± 3:52 minutes:seconds; 12%, 26:47 ± 4.31 minutes:seconds; p = 0.071; (Equation is included in full-text article.)= 0.15), heart rate (p = 0.095; (Equation is included in full-text article.)= 0.16), rating of perceived exertion (p = 0.195; (Equation is included in full-text article.)= 0.11), blood glucose (p = 0.920; (Equation is included in full-text article.)= 0.01), and blood lactate concentration (p = 0.831; (Equation is included in full-text article.)= 0.02), with only nonsignificant trivial to small differences between concentrations. Results of this study suggest that carbohydrate mouth rinsing provides no ergogenic advantage over an acaloric placebo (0%) and that there is no dose-response relationship between carbohydrate solution concentration and 5-km track running performance.

Physiological load associated with a Zumba(®) fitness workout: a comparison pilot study between classes and a DVD.

The objectives were to compare the metabolic load elicited by Zumba(®) classes and DVD workouts and link the physiological responses to participants' psychological characteristics. Fifteen women (25.4 ± 4.3 years old; 164.9 ± 5.1 cm; 56.9 ± 5.8 kg; 23.9 ± 4.9% body fat) performed three Zumba(®) classes and three Zumba(®) DVD workouts using a repeated measure design. Energy expenditure was assessed by extrapolating oxygen cost from heart rate (HR) using regressions from a preliminary incremental running test. Differences between Zumba(®) classes and Zumba(®) DVD workouts were assessed by Student's T tests and repeated measures analysis of variance and correlations between physiological and psychological variables by the Pearson's coefficient. Results showed that Zumba(®) classes allowed greater energy expenditure compared to Zumba(®) DVD workouts (6.8 ± 0.9 vs 5.6 ± 0.9 kcal · min(-1), 95% confidence interval (CI) limits: 0.3-2.1, P = 0.016), with significant differences in the time spent with a HR above 85% of HR reserve (14.7 vs 1.7%, 95% CI: 5.6-20.4, P = 0.021). Furthermore, women with a greater autonomy score showed a smaller difference between DVD and class (r = 0.511, P = 0.048), while greater differences were shown in women with greater interpersonal skills (r = -0.563, P = 0.028). The results suggest that while both types of workouts are suitable to maintain fitness Zumba(®) classes allow greater energy expenditure.

Severely obese adolescent girls rely earlier on carbohydrates during walking than normal-weight matched girls.

The purpose of this study was to determine the substrate oxidation rate and the exercise intensity at which maximal lipid oxidation and ventilatory threshold (VT) occur in obese (BMI: 36.6 ± 6.3 kg · m(-2)) and normal-weight adolescent girls (BMI: 18.7 ± 1.6 kg · m(-2)) aged 14-18 years. Substrate oxidation rate was determined by gas exchange using an incremental field test involving walking. Body composition was assessed by bioelectrical impedance. Carbohydrate oxidation rates were significantly higher in obese than in normal-weight girls at speeds ranging from 4 to 6 km · h(-1) (P < 0.05), whereas no significant differences were observed between groups regarding lipid oxidation rates. The crossover point of substrate utilisation and the VT were significantly lower in obese than in normal-weight adolescents (P < 0.05). Maximal lipid oxidation rate was observed at 46 ± 15 and 53 ± 15 %EVO2max in obese and normal-weight adolescents, respectively. At these intensities, the Lipox(max) was significantly lower in obese than in normal-weight girls (6.7 ± 2.3 versus 8.9 ± 3.5 mg · min(-1) · kg(-1) FFM, P < 0.05, 95% CI: -3.7 to -0.7, d = -0.74). The present results have implications in designing interventions to promote lipid oxidation and energy expenditure during walking in severely obese adolescent girls.

Reactive Agility Performance in Handball; Development and Evaluation of a Sport-Specific Measurement Protocol.

There is no current study that examined sport-specific tests of reactive-agility and change-of-direction-speed (CODS) to replicate real-sport environment in handball (team-handball). This investigation evaluated the reliability and validity of two novel tests designed to assess reactive-agility and CODS of handball players. Participants were female (25.14 ± 3.71 years of age; 1.77 ± 0.09 m and 74.1 ± 6.1 kg) and male handball players (26.9 ± 4.1 years of age; 1.90 ± 0.09 m and 93.90±4.6 kg). Variables included body height, body mass, body mass index, broad jump, 5-m sprint, CODS and reactive-agility tests. Results showed satisfactory reliability for reactive-agility-test and CODS-test (ICC of 0.85-0.93, and CV of 2.4-4.8%). The reactive-agility and CODS shared less than 20% of the common variance. The calculated index of perceptual and reactive capacity (P&RC; ratio between reactive-agility- and CODS-performance) is found to be valid measure in defining true-game reactive-agility performance in handball in both genders. Therefore, the handball athletes' P&RC should be used in the evaluation of real-game reactive-agility performance. Future studies should explore other sport-specific reactive-agility tests and factors associated to such performance in sports involving agile maneuvers. Key pointsReactive agility and change-of-direction-speed should be observed as independent qualities, even when tested over the same course and similar movement templateThe reactive-agility-performance of the handball athletes involved in defensive duties is closer to their non-reactive-agility-score than in their peers who are not involved in defensive dutiesThe handball specific "true-game" reactive-agility-performance should be evaluated as the ratio between reactive-agility and corresponding CODS performance.

An elliptical trainer may render the Wingate all-out test more anaerobic.

The purpose of this study was to evaluate the contribution of the 3 main energy pathways during a 30-second elliptical all-out test (EAT) compared with the Wingate all-out test (WAT). Participants were 12 male team sport players (age, 20.3 ± 1.8 years; body mass, 74.8 ± 12.4 kg; height, 176.0 ± 9.10 cm; body fat, 12.1 ± 1.0%). Net energy outputs from the oxidative, phospholytic, and glycolytic energy systems were calculated from oxygen uptake data recorded during 30-second test, the fast component of postexercise oxygen uptake kinetics, and peak blood lactate concentration, respectively. In addition, mechanical power indices were calculated. The main results showed that compared with WAT, EAT was characterized by significantly lower absolute and relative contributions of the oxidative system (16.9 ± 2.5 J vs. 19.8 ± 4.9 J; p ≤ 0.05 and 11.2 ± 1.5% vs. 15.7 ± 3.28%; p ≤ 0.001). In addition, significantly greater absolute and relative contributions of the phospholytic system (66.1 ± 15.8 J vs. 50.7 ± 15.9 J; p ≤ 0.01 and 43.8 ± 6.62% vs. 39.1 ± 6.87%; p ≤ 0.05) and a significantly greater absolute contribution of the glycolytic system (68.6 ± 18.4 J vs. 57.4 ± 13.7 J; p ≤ 0.01) were observed in EAT compared with WAT. Finally, all power indices, except the fatigue index, were significantly greater in EAT than WAT (p ≤ 0.05). Because of the significantly lower aerobic contribution in EAT compared with WAT, elliptical trainers may be a good alternative to cycle ergometers to assess anaerobic performance in athletes involved in whole-body activities.

Including stretches to a massage routine improves recovery from official matches in basketball players.

The aim of this study was to investigate the effect of incorporating stretches into a massage recovery treatment after a competitive basketball match on perceptual and physical markers of recovery. Nine men (age: 22 ± 3 years; stature: 191.2 ± 8.5 cm; body mass: 90.9 ± 10.1 kg; and body fat: 12.4 ± 4.7%) and 8 women (age: 21 ± 3 years; stature: 176.4 ± 8.1 cm; body mass: 73.9 ± 9.7 kg; and body fat: 21.9 ± 5.5%) who are national-level basketball players received a massage, a massage and stretching, or no treatment immediately after a competitive match. The perception of overall fatigue and leg soreness was assessed immediately after the treatment and 24 hours later, whereas countermovement jump (CMJ) and repeated sprint ability (RSA) were tested 24 hours after the treatment. Compared with massage, massage and stretching induced lower perception of leg soreness immediately only in women (p ≤ 0.001; (Equation is included in full-text article.)= 0.86), whereas a longer lasting effect was observed in men, with a difference between treatments reported after 24 hours (p ≤ 0.001; (Equation is included in full-text article.)= 0.94). Furthermore, both treatments resulted in a better CMJ performance compared with the control condition in men only (p = 0.0001; (Equation is included in full-text article.)= 0.33), and massage and stretching involved a lower performance decrement during RSA compared with massage in women only (p = 0.015; (Equation is included in full-text article.)= 0.29). The results suggest that women benefit slightly more from the combination treatment than men, and therefore this type of recovery intervention should be adopted by physiotherapists working with women teams in particular.

Effects of sports massage and intermittent cold-water immersion on recovery from matches by basketball players.

The aim of this study was to compare the effects of intermittent cold-water immersion and massage on perceptual and performance markers of recovery by basketball players after competitive matches. Eight men (age 23 ± 3 years; stature 190.5 ± 8.9 cm; body mass 90.3 ± 9.6 kg; body fat 12.8 ± 4.8%) and eight women (age 22 ± 2 years; stature 179.0 ± 8.5 cm; body mass 77.6 ± 9.2 kg; body fat 22.5 ± 6.6%) basketball players participated. Massage, cold-water immersion or control were applied immediately after competitive matches, followed by assessments of perceptual measures of recovery and physical performance, countermovement jump and repeated-sprint ability 24 h after intervention. There was lower perception of fatigue overall and in the legs immediately after the massage and cold-water immersion condition (P < 0.001; η²(P) = 0.91). Furthermore, women had a lower perception of fatigue in cold-water immersion than massage at any testing time (P < 0.001; η²(P) = 0.37). Jump performance was greater after cold-water immersion than the control condition (P = 0.037, η²(P) = 0.37). There was no effect of any of the recovery interventions on repeated-sprint measures (P at best 0.067, η²(P) at best 0.68). The results suggest that both massage and cold-water immersion improve perceptual measures of recovery. Furthermore, cold-water immersion improves jump performance although neither such immersion nor massage had an effect on repeated-sprint ability. This suggests that, overall, cold-water immersion is more useful than massage in the recovery from basketball matches, especially in women.

Effects of a Football Simulated Exercise on Injury Risk Factors for Anterior Cruciate Ligament (ACL) Injury in Amateur Female Players.

Females are more at risk of Anterior Cruciate Ligament (ACL) injuries than males; however, there is limited literature on neuromuscular risk factors such as angle-specific hamstring/quadriceps functional strength ratios (Hecc/Qcon) and rate of torque development (RTD) in female footballers. The aim of this study was to investigate the effects of fatigue on these neuromuscular risk factors. Thirty-three amateur players (20.3 ± 2.0 years old, 1.67 ± 9.31 m, 63.4 ±8.1 kg, 23.6 ± 5.7% body fat) performed strength assessments of the quadriceps (concentrically, Qcon) and hamstrings (eccentrically, Hecc) on both legs on an isokinetic dynamometer, before and immediately after a football-specific exercise. Results showed significantly lower peak Hecc (-15.1 to -15.5%), peak Hecc/Qcon (-8.8 to -12.9%) and RTD (-14.0 to -17.0%) for hamstring eccentric contractions after fatigue in the dominant and non-dominant legs. Furthermore, significant decreases in Hecc/Qcon were observed at 10° only in the dominant leg (-15.5%), and at 10°, 20° and 30° in the non-dominant leg (-15.1 to -21.8%). These results suggest a reduced capacity of the hamstrings to stabilise the knee joint with fatigue. Unlike results previously shown on men, the non-dominant leg seemed more affected, highlighting the need to consider specific prevention measures in females.

The comparative effect of exercise interventions on balance in perimenopausal and early postmenopausal women: A systematic review and network meta-analysis of randomised, controlled trials.

In addition to a range of physiological and psychological symptoms, menopause causes a decrement to balance performance and risk of falls. This review aimed to determine the effects of exercise interventions on balance in perimenopausal and early postmenopausal women. Web of Science, PubMed, CINAHL, SPORTDiscus and Cochrane Central Register of Controlled Trials databases were searched. Randomised, controlled trials of exercise interventions in perimenopausal or early postmenopausal populations with an average age of 65 years or younger reporting balance measures were included. Risk of bias was assessed using Cochrane RoB 2. A random effects model network meta-analysis was performed to assess the effect of exercise on balance. Standardised mean differences with 95 % confidence intervals were used as the measure of effect. Twenty-six studies were included after screening. Network meta-analyses were conducted for 5 balance variables. Whole-body vibration (standardised mean difference: 2.25, confidence interval: 0.08; 4.43), balance (standardised mean difference: 1.84, confidence interval: 0.15; 3.53), balance + nutrition (standardised mean difference: 3.81, confidence interval: 1.57; 6.05) and resistance (standardised mean difference: 1.43, confidence interval: 0.41; 2.46) exercise improved Berg balance scale performance. Resistance + aerobic + balance exercise improved one-leg stance (standardised mean difference: 0.80, confidence interval: 0.39; 1.22) and whole-body vibration improved anterior-posterior (standardised mean difference: -0.89, confidence interval: -1.48; -0.31), medio-lateral (standardised mean difference: -0.58, confidence interval: -1.15; -0.01) postural sway and falls indices (standardised mean difference: -0.75, confidence interval: -1.45; -0.04). Exercise improved all balance measures and should be considered as an adjunct therapy in perimenopausal and postmenopausal women. Whole-body vibration was most frequently the highest ranked intervention; resistance and balance training also improved balance.

Effects of sprint versus strength training on risk factors for hamstring injury in football players.

BACKGROUND: This study aimed to compare the effects of in-season sprint training vs. Nordic hamstring exercise (NHE) training on risk factors for hamstring strain injuries (HSI). METHODS: Eighteen male university football players (20.9±2.5 years; 181±7 cm; 75.8±9.1 kg; 15.2±3.5% of body fat) were randomly allocated to a sprint group or NHE group. They completed baseline isokinetic strength and sprint mechanics assessments prior to their assigned intervention performed twice weekly for 4-weeks, before post-testing. A mixed design ANOVA with repeated measures assessed time, group and interaction effects for all risk factors. RESULTS: There were significant increases in hamstring eccentric peak torque at 60°·s-1 (+8% - 9.9%), the torque produced at 20° (+15%) and 10° (+21% - 31%), as well as a rightward shift in angle of peak torque towards knee extension (-27% - -36%) in both groups (P<0.05). We also observed a significant increase (+24.5%) in hamstring eccentric peak torque at 180°·s-1 in the strength group only and significant improvements (+29.4%) in the rate of torque development of the dominant leg at 60°·s-1 in the sprint group only (P<0.05). No significant effect was noted on sprint performance or sprint mechanics (P>0.05). CONCLUSIONS: These findings suggest that both training programs can be effective to mitigate the risk of HSI, but through different mechanisms.

The Role of Strength-Related Factors on Psychological Readiness for Return to Sport Following Anterior Cruciate Ligament (ACL) Reconstruction.

Psychological readiness following anterior cruciate ligament reconstruction (ACLR) correlates with different return to sport outcomes. However, the relationship between strength and power and psychological readiness remains unexplored. The aim of this study was to investigate the relationship between anterior cruciate ligament return to sport after injury (ACL-RSI) scores and various hamstrings and quadriceps strength and power variables. Twelve participants (20.7 ± 2.5 years old; 174.2 ± 7.5 cm; 70.2 ± 8.5 kg; 18.2 ± 8.3% of body fat) who had an ACLR nine months or more before the study completed the ACL-RSI questionnaire and isokinetic strength testing of the hamstrings and quadriceps (60°·s-1 and 180°·s-1). Based on ACL-RSI scores, they were divided into "cases" and "controls", deemed not psychologically ready and psychologically ready to return to previous sport performance (PILOS), respectively. The main findings are that quadriceps' and hamstrings' rate of torque development (RTD) and time since surgery were determinants of psychological readiness following ACLR. Furthermore, compared to controls, cases showed significantly lower quadriceps torque at angles close to full knee extension (40 deg and 30 deg from extension). They also showed lower RTD than controls, but no difference in peak torque. These results suggest that physiotherapists should facilitate athletes' return to sport (RTS) by focusing on the restoration of RTD and strength at angles close to full knee extension.

The Relationship Between Motor Competence Physical Activity Cardiorespiratory Fitness and BMI in UK Adolescents.

Purpose: This study set out to identify the extent of the relationships between subsections of the Movement Assessment Battery for Children 2nd Edition - MABC2 (manual dexterity, aiming and catching, and balance) to PA, CRF and BMI in adolescents. Methods: Height, BMI, the MABC2, a 20m shuttle run test and wrist-worn accelerometery PA levels (mins) were measured. Multivariable linear regression models, adjusting for sex, height and BMI were used to assess the relationship of the three subsections of the MABC2 with PA, CRF and BMI. Results: A total of 155 adolescents, aged 13-14 years, took part in this study (77 girls, 78 boys). Balance reported significant relationships with moderate to vigorous PA (unstandardised Beta B=0.15, 95%CI 0.02-0.28), vigorous PA (B=0.06, 95%CI 0.02-0.09) and BMI (B=-0.01, 95%CI -0.02-0.005). Balance in addition to aiming and catching skills were both significantly related to adolescent CRF (B=0.30, 95%CI 0.17-0.42 and B=0.29, 95%CI 0.14-0.45, respectively). Conclusion: This study suggests that balance is the strongest correlate skill to achieving the highest intensities of PA and healthier BMI status in adolescents. .