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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.

We aimed to (1) compare external training loads obtained in futsal players during pre-season and in-season training weeks to explore how these loads are periodized by the coaching staff; and (2) compare the external training loads using the match day minus approach during the pre-season and in-season periods to determine how the within-microcycle training load varies between these periods. A total of 432 recordings were obtained of twelve national-level male amateur players using IPS devices. These data were collected over four consecutive microcycles from the beginning to the end of the pre-season, as well as during four additional consecutive microcycles at the start of the in-season. The external load variables evaluated were: total distance covered (TD; m), relative distance covered (Drel; m/min), high-speed running (HSR; m > 18.8 km/h), sprint distance (SPR; m > 25.2 km/h), number of intense accelerations (ACC; >2.5 m/s2) and decelerations (DEC; >−2.5 m/s2). Results indicated significant week-by-week variation (p < 0.05) in all external load variables during the pre-season. During the in-season, significant variations (p < 0.05) were observed only in Drel, HSR, and ACC. In both phases, all variables were higher (p < 0.05) two days before the match. In conclusion, it is important to consistently quantify the external loads of futsal players to ensure appropriate variation in loading and tapering within the microcycle, as well as during the pre-season and in-season periods. [ABSTRACT FROM AUTHOR]

Purpose: To determine whether daily perceived recovery is explained from a multifactorial single-session classification of recovery (ie, faster vs slower) or other circumstantial factors (ie, previous training load, self-reported sleep, or phase of the microcycle). Methods: Nineteen elite male futsal players were initially allocated to a recovery-classification group (faster recovery, slower physiological, or slower perceptual) based on previous research using a multifactorial cluster-analysis technique. During 4 ensuing weeks of preseason, training loads were monitored via player load, training impulse, and session rating of perceived exertion. Before each day's training, players reported their perception of recovery (Total Quality of Recovery scale [TQR]) and the number of hours and perceived quality of sleep the night prior. A hierarchical linear mixed model was used to analyze the effect of the different recovery profiles, training load, sleep, and phase of the microcycle (ie, start, middle, end) on daily TQR. Results: The recovery classification of players (P =.20), training load (training impulse, P =.32; player load, P =.23; session rating of perceived exertion, P =.46), and self-reported hours slept the night before (P =.45) did not significantly influence TQR. However, perceived sleep quality (P <.01) and phase of the microcycle (P <.01) were significantly associated with TQR (r2 =.41). Conclusions: Neither recovery classification nor prior training load influenced perceived recovery during the preseason. However, higher TQR was evident with better self-reported sleep quality, whereas lower values were associated with phases of the training week. [ABSTRACT FROM AUTHOR]

Literature lacks evidence about the physiological recovery of tennis players between points. This study aimed to: (i) verify the heart rate (HR) and oxygen uptake (V̇O2) recovery variance in young tennis players from the end of a tennis drill until the 25-s mark and onwards (65-s limit), performed at several intensities, and (ii) test the curve fitting that better characterizes the players' HR and V̇O2 recovery, from the end of the drill until the 65-s mark. The sample was composed of 13 male tennis players (age: 16.80 ± 1.61 years) recruited from a National Tennis Association. Players were instructed to perform a drill test ("two-line drill wide mode") based on an intensity increment protocol. Three levels of intensity were used based on the reserve HR and V̇O2. A significance level effect was observed on the HRreserve and V̇O2reserve (P <.001). At all three levels of intensity, the first 25 s were enough to significantly (P <.001) recover the HRreserve and V̇O2reserve. The same significance trend (P <.001) was maintained until the 65 s but with a lower magnitude over time. Overall, the HR and V̇O2 curve fitting indicated a cubic relationship at the three levels of intensity (except the V̇O2 at the first level). Considering the specific test performed, players significantly elicited their physiological profile for every additional 10 s (after the 25-s rule) in the three levels of intensity performed. Despite this being a drill test and not a competitive point, coaches, players, and tennis organizations should be aware of these findings. [ABSTRACT FROM AUTHOR]

This study examined the intra-session reliability of sprint performance on a non-motorized treadmill amongst healthy, active male and female adults. One hundred and twenty participants (males n = 77; females n = 45) completed two familiarization sessions, followed by a third session that consisted of three trials (T1, T2, T3) of maximal sprints (4-s), interspersed by three minutes of recovery. Combining males and females exhibited moderate-to-excellent test-retest reliability (intra-class correlation coefficient, ICC), minimal measurement error (coefficient of variation, CV) and trivial differences between trials (effect size, ES) for speed, power, total work and acceleration (ICC = 0.82-0.98, CV = 1.31-8.45%, ES = 0.01-0.22). The measurement error was improved between comparisons of T1 vs. T2 (CV = 1.62-8.45%, ES = 0.12-0.22) to T2 vs. T3 (CV = 1.31-6.56%, ES = 0.01-0.07) and better for females (CV = 1.26-7.94%, ES = 0.001-0.26) than males (CV = 1.33-8.53%, ES = 0.06-0.31). The current study demonstrated moderate-to-excellent reliability and good-moderate measurement error during a 4-s sprint on a non-motorized treadmill. However, sex had a substantial impact with females exhibiting better values. Practitioners should employ at least two separate trials within a session, in addition to multiple familiarization sessions, to achieve reliable non-motorized treadmill sprint performances. [ABSTRACT FROM AUTHOR]

The present study aimed to select the most critical external workload variables that explain sports performance in the Mexican male professional soccer League (Liga BBVA-Bancomer) and analyse the effect of match period and match outcome in workload demands. 480 professional soccer players that belonged to 16 Liga BBVA-Bancomerteams were registered during the 2018–2019 opening and closing tournament by inertial measurement units. The statistical analysis was composed of: (1) principal component analysis (PCA) to select the most critical performance indicators, and (2) mixed analysis of variance to explore match outcome and match period effects. Through PCA analysis, eight variables were selected and distributed in three components that represented the 59.47% (opening tournament) and 58.85% (closing tournament) of total variance with three different PC´s as: high-intensity actions (RelDist, ExplDist, Speed18-21 km/h and Speed21-24 km/h), speed changes (Acc and Dec) and actions at maximum capacity (AccMax and SpeedMax). Differences in tournaments and match periods were found in almost all variables, finding the highest external workload in draw matches when match outcome was considered a factor. PCA analysis seems to be a helpful method to discriminate the most representative variables of performance. [ABSTRACT FROM AUTHOR]

This study aimed to identify the most important variables of male and female beach handball workload demands and compare them by sex. A total of 92 elite Brazilian beach handball players (54 male: age 22.1 ± 2.6 years, height 1.8 ± 0.5 m, weight 77.6 ± 13.4 kg; and 38 female: age 24.4 ± 5.5 years, height 1.7 ± 0.5 m, weight 67.5 ± 6.5 kg) were analyzed in 24 official matches during a four-day congested tournament. From 250 variables measured by the inertial measurement unit, fourteen were extracted for analysis using Principal Component Analysis as selection criteria. Five Principal Components (PC) were extracted that explained 81.2--82.8% of total variance (overview of workload demands during beach handball). Specifically, 36.2--39.3% was explained by PC1 (DistanceExpl, Distance, Distance4--7 km/h, and Acc), 15--18% by PC2 (AccMax, Acc3--4 m/s, Dec4--3 m/s), 10.7--12.9% by PC3 (JumpsAvg Take-Off, JumpsAvg Landing and PLRT), 8--9.4% by PC4 (Distance >18.1 km/h, SpeedMax), and 6.7--7.7% by PC5 (HRAvg and Step Balance). Sex-related differences were found in the PC distribution of variables, as well as in selected variables (HRAvg, Dec4--3 m/s, Acc3--4 m/s, JumpsAvg Take-Off, JumpsAvg Landing, AccMax, Distance, Distance4--7 km/h, Acc, SpeedMax) with higher values in male players (p < .05). In conclusion, the sex-related PC distribution and workload demands in beach handball should consider for training design and injury prevention programs. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the existence of faster vs slower recovery profiles in futsal and factors distinguishing them. Methods: 22 male futsal players were evaluated in countennovement jump, 10-m sprint, creatine kinase, total quality of recovery (TQR), and Brunei Mood Scale (fatigue and vigor) before and immediately and 3, 24, and 48 h posttraining. Hierarchical cluster analysis allocated players to different recovery profiles using the area under the curve (AUC) of the percentage differences from baseline. One-way ANOVA compared the time course of each variable and players' characteristics between clusters. Results: Three clusters were identified and labeled faster recovery (FR), slower physiological recovery (SLphy), and slower perceptual recovery (SLperc)- FR presented better AUC in 10-m sprint than SLphy (P = .001) and SLperc (P = .008), as well as better TQR SLphy {P = .018) and SLperc (P = .026). SLperc showed better AUC in countermovement jump than SLphy (P = .014) but presented worse fatigue AUC than SLphy (P = .014) and FR (P = .008). AUC of creatine kinase was worse in SLphy than in FR (P = .001) and SLperc {P < .001). The SLphy players were younger than SLperc players (P = .027), whereas FR were slower 10-m sprinters than SLphy players (P = .003) and SLperc (P = .013) and tended to have higher maximal oxygen consumption than SLphy (effect size = 1.13). Conclusion: Different posttraining recovery profiles exist in futsal players, possibly influenced by their physical abilities and age/experience. [ABSTRACT FROM AUTHOR]

Flatt, AA, Hornikel, B, Nakamura, FY, and Esco, MR. Effect of competitive status and experience on heart rate variability profiles in collegiate sprint-swimmers. J Strength Cond Res 36(10): 2898–2904, 2022—Interindividual differences in training history may be a determinant of heart rate variability (HRV) profiles in collegiate sprint-swimmers and may account for differences observed between elite and subelite athletes. We therefore compared HRV profiles among national-level and conference-level sprint-swimmers while accounting for individual swim-training history. Twenty-eight short-distance swimmers (18 men and 10 women) recorded postwaking HRV throughout a 4-week standardized training period. The 4-week mean (M) and coefficient of variation (CV, a marker of daily fluctuation) were calculated for resting heart rate (RHR) and the natural logarithm of the root mean square of successive differences (LnRMSSD). Swimmers were categorized as national-level (n = 12) or conference-level (n = 16) competitors. Years of competitive experience was documented for each individual to index training history. p < 0.05 was considered statistically significant. No sex-related differences were observed for any variables (p > 0.05). LnRMSSDM (effect size [ES] = 0.95), LnRMSSDCV (ES = −1.18), RHRCV (ES = −1.05), and competitive experience (ES = 1.23) differed between status groups (p < 0.05). Accounting for multicollinearity between competitive experience and LnRMSSD variables (p < 0.05), competitive experience remained associated with LnRMSSDM (r = 0.44, p = 0.02). With competitive experience included as a covariate, differences in LnRMSSDM between status groups disappeared (p > 0.05, ES = 0.31). National-level swimmers exhibit higher and more stable LnRMSSD than that of their conference-level teammates throughout standardized training. Differences in trend characteristics were attributed to training age. This information may assist practitioners with interpreting interindividual differences in HRV profiles throughout training periods among a mixed roster of athletes. [ABSTRACT FROM AUTHOR]

This study aimed to determine if the OMNI scale with cycle ergometer pictorial format can be used to estimate perceived exertion threshold ([PET.sub.OMNI]) and nonexhaustive PET ([PET.sub.OMNI5-8]) and to compare and to correlate these PET estimates with [PET.sub.Borg], [PET.sub.Borg14-17], and critical power (CP). During different days, 13 men performed 4 different high-intensity constant-loads work bouts until exhaustion on a cycle ergometer using the Borg scale, whereas the OMNI scale was used during the other 4 work bouts using previous constant loads. The PET for both scales was determined by plotting the increasing rates of perceived exertion against power outputs, PET being the intersection point of the regression line. In addition, a hyperbolic relationship between power and time to exhaustion was used to determine CP. The [PET.sub.OMNI] (183 [+ or -] 36 W) was similar to [PET.sub.Borg] (178 [+ or -] 46 W), and they were also significantly correlated (r = 0.77). The [PET.sub.OMNI5-8] (175 [+ or -] 36 W) was similar to [PET.sub.Borg14-17] (181 [+ or -] 38 W); however, they were not significantly correlated (r = 0.36). All the PET estimates were similar to [CP.sub.OMNI] (167 [+ or -] 36 W) and [CP.sub.Borg] (169 [+ or -] 40 W) and also significantly correlated (r = 0.79-0.94), excepting [PET.sub.OMNI5-8] (r = 0.46). In conclusion, OMNI cycling scale can be used to estimate PET and CP with high accuracy. However, the nonexhaustive PET derived from the 5-8 range in the OMNI scale did not provide a valid estimate of maximal sustainable power output because of the absence of correlation with [PET.sub.Borg14-17] and with CP. Therefore, professionals and practitioners can assess the subjects' aerobic fitness through the PET estimation using the OMNI scale during exhaustive tests. KEY WORDS rating of perceived exertion, Borg scale, critical power, cycle ergometer

The aim of this study was to investigate the effects of preferred and nonpreferred music on exercise distance, Heart Rate (HR), and Rating of Perceived Exertion (RPE) during continuous cycling exercise performed at high intensity. Fifteen participants performed five test sessions. During two sessions, they cycled with fixed workload on ergometer to determine the Critical Power (CP) intensity. Then, they performed three more sessions cycling at CP intensity: listening to Preferred Music, listening to Nonpreferred Music, and No Music. The HR responses in the exercise sessions did not differ among all conditions. However, the RPE was higher for Nonpreferred Music than in the other conditions. The performance under Preferred Music (9.8 [+ or -] 4.6km) was greater than under Nonpreferred Music (7.1 [+ or -] 3.5km) conditions. Therefore, listening to Preferred Music during continuous cycling exercise at high intensity can increase the exercise distance, and individuals listening to Nonpreferred Music can perceive more discomfort caused by the exercise. DOI 10.2466/PMS.110.1.257-264

This study tested the concurrent and construct validity of a newly developed OMNI-Kayak Scale, testing 8 male kayakers who performed a flatwater load-incremented 'shuttle' test over a 500-m course and 3 estimation-production trials over a 1,000-m course. Velocity; blood lactate concentration, heart rate, and rating of perceived exertion (RPE), using the OMNI-Kayak RPE Scale and the Borg 6-20 Scale were recorded. OMNI-Kayak Scale RPE was highly correlated with velocity, the Borg 6-20 Scale RPE, blood lactate, and heart rate for both load-incremented test (rs = .87-.96), and estimation trials (rs = .75-.90). There were no significant differences among velocities, heart rate and blood lactate concentration between estimation and production trials. The OMNI-Kayak RPE Scale showed concurrent and construct validity in assessing perception of effort in flatwater kayaking and is a valid tool for self-regulation of exercise intensity.

The purpose of this study was to evaluate a novel procedure, based on the perceived exertion threshold (PET) concept, involving non-exhaustive tests ([PET.sub.14-17]) to estimate critical power (CP), as well as to examine the reproducibility of these indices. Twenty young men performed 2 trials (Trial 1 and Trial 2) of 4 exhaustive predictive tests to estimate CP, PET, and [PET.sub.14 17]. The slope coefficients of the regression lines corresponding to the ratings of perceived exertion (RPE) versus time relationship (y axis) obtained during the predictive tests were plotted against the power outputs (x axis) to estimate PET. PET was calculated as the intersection point of the regression line in the power axis. The 14-1 7 RPE range of each predictive test was modeled using the same mathematical procedures used to estimate [PET.sub.14 17]. CP was derived from the power-time hyperbolic equation. Analysis of variance revealed no significant differences among CP (189-194 W), PET (190-191 W) and [PET.sub.14 17], (191-195 W). The correlations between CP and PET (r = 0.87), CP and [PET.sub.14 17] (r = 0.89), and PET and [PET.sub.14 17] (r = 0.88) were all strong. Additionally, the bias [+ or -] limits of agreement when plotting CP and PET was -2.16 [+ or -] 31.60 W, and -5.70 [+ or -] 31.21 W when comparing CP and [PET.sub.14 17]. Relatively high reproducibility levels of CP (ICC = 0.96), PET (ICC = 0.85) and [PET.sub.14 17] (ICC = 0.83) were recorded in the test-retest fashion. It can be concluded that the [PET.sub.14 17] can be utilized with relatively high accuracy and reproducibility to estimate CP without causing exhaustion in the subjects. KEY WORDS critical power, rating of perceived exertion, cycle ergometer

Older women participated in a 12-week high-speed resistance training program under two supervisor-to-subject ratio methods (i.e., high versus low supervision) to assess its effects on muscle strength, power, functional performance, and quality of life assessed before (T1) and after (T2) intervention. Women were divided into either the control group (CG, n = 15), high supervision group (HSG, n = 30), or low supervision group (LSG, n = 28). The training program included exercises requiring high-speed concentric muscle actions. No differences were observed among groups at T1. Between T1 and T2, the HSG showed a higher (p < .05) improvement in muscle strength (ES = 0.36–1.26), power (ES = 0.5–0.88), functional performance (ES = 0.52–0.78), and quality of life (ES = 0.44–0.82) compared with LSG and CG. High-speed resistance training under closer supervision is more effective for improving muscle strength, power, functional performance, and quality of life in older women. [ABSTRACT FROM AUTHOR]

Furthermore, in the present study, the sprint test was better linked to traditional COD tests (i.e., 505) than to the On-Court COD test, suggesting than the inclusion of specific lower-limb movements along with badminton mock shots makes the On-Court COD test a very specific COD measurement. Keywords: racket sports; specific movement; neuromuscular performance; testing EN racket sports specific movement neuromuscular performance testing 155 164 10 04/29/22 20220415 NES 220415 Introduction As an intermittent sport, badminton is characterized by repetitive short periods of exercise (i.e., 1-9 s) and recovery (i.e., low intensity activities such as standing and walking for 6-15s) interspersed with longer breaks in play (i.e., "time outs" of 120s between games) ([33]). The excellent reliability of the On-Court COD test agrees with previous research revealing that certain specific badminton COD tests are highly reproducible ([6]; [32]), supporting its use in badminton fitness testing batteries. [Extracted from the article]