Effects of HMB on Endurance Performance in a Healthy Population: A Systematic Review and Meta-Analysis.

ABSTRACT: Fernández-Landa, J, Todorovic, N, Santibañez-Gutierrez, A, Ostojic, SM, Calleja-González, J, Sekulic, D, and Mielgo-Ayuso, J. Effects of HMB on endurance performance in a healthy population: a systematic review and meta-analysis. J Strength Cond Res 38(4): e202-e210, 2024-ß-hydroxy-ß-methylbutyrate (HMB) has been used extensively as a dietary supplement for athletes and physically active people. However, the ergogenic effect of HMB supplementation on endurance performance is still unclear. Therefore, this systematic review and meta-analysis (SRMA) aimed to assess HMB supplementation on endurance performance and V̇O 2 max . This SRMA followed PRISMA guidelines. Three electronic databases were searched (PubMed/Medline, Web of Science [WOS], and Scopus) from inception until April 3, 2023. In this SRMA, human experimental trials, controlled with a placebo group, assessing the effect of HMB supplementation on endurance performance in a healthy population were included. The quality of the studies was assessed by the Physiotherapy Evidence Database (PEDro) scale. The study protocol was registered in the Prospective Register of Systematic Review (PROSPERO): CRD42022341790. Eleven studies involving 279 participants met the inclusion criteria. The results displayed a significant improvement on endurance performance (pooled standardized mean difference [SMD] = 0.58 [0.28-0.87]) and V̇O 2 max (pooled SMD = 0.58 [0.21-0.95]) after HMB ingestion. Moreover, after the exclusion of the studies not evenly distributed around the base of the funnel plot, the results continued to be significantly positive in endurance performance (pooled SMD = 0.38 [0.22-0.53]) and V̇O 2 max (pooled SMD = 0.25 [0.09-0.42]). In conclusion, HMB (3 g·d -1 ) ingestion during 2-12 weeks significantly improves endurance performance and V̇O 2 max .

Physical Exercise-Induced DNA Methylation in Disease-Related Genes in Healthy Adults-A Systematic Review With Bioinformatic Analysis.

ABSTRACT: Vasileva, F, Hristovski, R, Font-Lladó, R, Georgiev, G, Sacot, A, López-Ros, V, Calleja-González, J, Barretina-Ginesta, J, López-Bermejo, A, and Prats-Puig, A. Physical exercise-induced DNA methylation in disease-related genes in healthy adults-A systematic review with bioinformatic analysis. J Strength Cond Res 38(2): 384-393, 2024-This study aimed to systematically review the existing literature regarding physical exercise (PE) and DNA methylation (DNAm) in healthy adults. Specific goals were to (a) identify differently methylated genes (DMGs) after PE intervention, their imprinting status, chromosome and genomic location, function, and related diseases; and (b) to screen for core genes and identify methylation changes of the core genes that can be modified by PE intervention. Our search identified 2,869 articles from which 8 were finally included. We identified 1851 DMGs ( p < 0.05) after PE intervention, although 45 of them were imprinted. Aerobic exercise (AE) seems to induce more DNA hypermethylation rather than hypomethylation, whereas anaerobic exercise (AN) seems to induce more DNA hypomethylation rather than hypermethylation. Aerobic exercise induced highest % of methylation changes on chromosome 6, whereas AN and mixed type (MT) on chromosome 1. Mixed type induced higher % of methylation changes close to transcription start site in comparison to AE and AN. After PE intervention, DMGs were mainly involved in fat metabolism, cell growth, and neuronal differentiation, whereas diseases regulated by those genes were mainly chronic diseases (metabolic, cardiovascular, neurodegenerative). Finally, 19 core genes were identified among DMGs, all related to protein metabolism. In conclusion, our findings may shed some light on the mechanisms explaining PE-induced health benefits such as the potential role that PE-induced DNAm may have in disease prevention and disease treatment.

Pupillometry as a new window to player fatigue? A glimpse inside the eyes of a Euro Cup Women's Basketball team.

A rapidly emerging area of interest in high-pressure environments is that of pupillometry, where handheld quantitative infrared pupillometers (HQIPs) are able to track psycho-physiological fatigue in a fast, objective, valid, reliable, and non-invasive manner. However, the application of HQIPs in the context of athlete monitoring is yet to be determined. Therefore, the main aim of this pilot study was to examine the potential usefulness of a HQIP to monitor game-induced fatigue inside a professional female basketball setting by determining its (1) test-retest repeatability, (2) relationship with other biomarkers of game-induced fatigue, and (3) time-course from rested to fatigued states. A non-ophthalmologic practitioner performed a standardized Pupil Light Reflex (PLR) test using a medically graded HQIP among 9 professional female basketball players (2020-2021 Euro Cup) at baseline, 24-h pre-game (GD-1), 24-h post-game (GD+1) and 48-h post-game (GD+2). This was repeated over four subsequent games, equalling a total of 351 observations per eye. Two out of seven pupillometrics displayed good ICCs (0.95-0.99) (MinD and MaxD). Strong significant relationships were found between MaxD, MinD, and all registered biomarkers of game-induced fatigue (r = 0.69-0.82, p < 0.05), as well as between CV, MCV, and cognitive, lower-extremity muscle, and physiological fatigue markers (r = 0.74-0.76, p < 0.05). Three pupillometrics were able to detect a significant difference between rested and fatigued states. In particular, PC (right) (F = 5.173, η2 = 0.115 p = 0.028) and MCV (right) (F = 3.976, η2 = 0.090 p = 0.049) significantly decreased from baseline to GD+2, and LAT (left) (F = 4.023, η2 = 0.109 p = 0.009) significantly increased from GD-1 to GD+2. HQIPs have opened a new window of opportunity for monitoring game-induced fatigue in professional female basketball players. However, future research initiatives across larger and heterogenous samples, and longer investigation periods, are required to expand upon these preliminary findings.

Quality of lean body mass and jump capacity in high performance young basketball players lean body mass and jump capacity.

The lean body mass (LBM) components have been suggested as important predictors of anaerobic performance, which is highly involved in basketball. We explored with descriptive cross-sectional design the relationship between anaerobic performance and full molecular and cellular body composition profile in young male basketball players. Twenty-one players (age = 16.8 ± 1.6 years; body mass = 76.3 ± 15.7 kg, height = 189.3 ± 12.6 cm) were recruited, 11 elite and 10 local level. Participants were evaluated on multicomponent body composition [LBM, appendicular lean soft tissue (ALST), bone mineral content (BMC), total body water (TBW), intracellular water (ICW) and extracellular water (ECW)] and field-based anaerobic performance (vertical jump, linear sprint, and handgrip strength). The stepwise regression analyses adjusted for confounders showed significant relationships of whole-body and regional body composition components with handgrip and jump performance (P ≤ 0.03). Prediction models combining body composition variables assessed by bioimpedance analysis (BIA) and double-energy X-ray absorptiometry (DXA) revealed that lean mass and hydration ratios (ICW/ECW and ECW/TBW) were strongly associated with jump performance (CMJ and CMJ25kg), independently of the competition level (P < 0.01). The novel finding in this study was that water quality (ICW/ECW) and water distribution (ECW/TBW, ICW) of total and regional LBM were the main predictors of vertical jump capacity in young basketball players.

Monitoring Internal Load in Women's Basketball via Subjective and Device-Based Methods: A Systematic Review.

The monitoring of internal load in basketball can be used to understand the effects and potential physiological adaptations caused by external load. The main aim of this systematic review was to identify the methods and variables used to quantify internal load in female basketball. The studies included different populations and events: youth athletes, elite, and amateur players. Subjective methods included using the rating of perceived exertion (RPE) method, and sensor-based methods included monitoring the cardiac response to exercise, using heart rate (HR) as the primary metric. The results showed that the HRAvg exhibited a wider range of values during training than during competition, and different metrics were used to evaluate internal load, such as HRMax, HRmin, %HRMax, total time and % of time spent in different HR zones (2-8 zones), Banister's TRIMP, and summated HR zones. RPE and HR metrics were the most commonly used methods. However, the use of multiple metrics with little standardization resulted in significant heterogeneity among studies, limiting meaningful comparisons. The review provides a reference for current research on female basketball. Future research could address this limitation by adopting more consistent measurement protocols standardizing the use of metrics.

Performance indicators and functional adaptive windows in competitive cyclists: effect of one-year strength and conditioning training programme.

Changes and relationships between cycling performance indicators following a one-year strength and conditioning training have not been totally clarified. The aims of this study are to investigate (i) the effect of a combined one-year strength and conditioning training programme on performance indicators and the possible relationships between these indicators, and (ii) the existence of possible endurance-functional-adaptive windows (EFAWs) linked to changes in muscular strength and body composition markers. Functional and lactate threshold power (FTP and LTP), maximal strength (1RM) and body composition (body mass index [BMI], body cell mass [BCM] and phase angle [PA]) were measured at the beginning and the end of a one-year strength and conditioning training programme of thirty cyclists. Correlations, differences, and predictive analysis were performed among parameters. Significant differences were found between pre- and post-conditioning programme results for FTP, LTP, 1RM (p < 0.0001) and BCM (p = 0.038). When expressed as power output (W), FTP and LTP were significantly correlated with 1RM (r = 0.36, p = 0.005 and r = 0.37, p = 0.004, respectively), body mass (r = 0.30 and p = 0.02), BCM (r = 0.68, p < 0.001) and PA (r = 0.42 and 0.39, respectively and p < 0.001). When expressed as W·kg-¹, these power thresholds were strongly correlated with body mass (r = -0.56 and -0.61, respectively) and BMI (r = -0.57 and -0.61 respectively) with p < 0.001. Predictive polynomial regressions revealed possible endurance and strength adaptation zones. The present findings indicated beneficial impacts of one-year strength and conditioning training on cycling performance indicators, confirmed the correlation between performance indicators, and suggested the existence of different EFAWs. Strategies aiming to improve performance should consider cyclist characteristics and performance goals to achieve EFAWs and thereby enhance cycling performance.

Differences in Change of Direction Speed and Deficit Between Male and Female National Rugby Sevens Players.

ABSTRACT: Freitas, TT, Alcaraz, PE, Calleja-González, J, Arruda, AFS, Guerriero, A, Kobal, R, Reis, VP, Pereira, LA, and Loturco, I. Differences in change of direction speed and deficit between male and female national rugby sevens players. J Strength Cond Res 35(11): 3170-3176, 2021-The aims of this study were to assess the change of direction (COD) deficit in different tasks and to investigate the differences in COD ability and COD deficit between male and female rugby sevens players. Thirty-six elite rugby players from the Brazilian National senior sevens teams (18 males and 18 females) completed the following physical assessments: squat and countermovement jumps; drop jump from a 45-cm height; horizontal single and triple jumps; 40-m linear sprint; Pro-agility, L-drill, and Zig-zag COD tests; and 1 repetition maximum test in the squat exercise. The differences between male and female performances were determined using magnitude-based inferences, an independent t test, and effect sizes (ES). Pearson's product-moment correlations were performed to determine the relationships among the different COD velocities and COD deficits. Men demonstrated likely to almost certainly significantly higher performances than women in all speed-power assessments and COD tasks (ES ranging from 0.61 to 2.09; p < 0.05), with the exception of the Zig-zag drill (ES = 0.24; p > 0.05). Furthermore, males displayed significantly greater COD deficits in all tests and higher sprint momentum (ES ranging from 0.78 to 2.95; p < 0.05). Large significant relationships among COD velocities (r ranging from 0.71 to 0.88; p < 0.05) and almost perfect significant correlations among all COD deficits (r ranging from 0.90 to 0.95; p < 0.05) were obtained in both sexes. The present results indicate that male rugby players are less efficient at changing direction, relative to their maximum sprint velocity. In addition, the correlations between the different COD deficits and COD speeds suggest that elite rugby players demonstrate similar ability to change direction, independently of the angle of directional change. From a practical perspective, this implies that a more comprehensive training strategy including eccentric exercises, acceleration-deceleration drills, and directional change technique is warranted to improve the COD ability (and reduce the COD deficit) of faster and more powerful rugby sevens players.

Effects of the COVID-19 Lockdown on Neuromuscular Performance and Body Composition in Elite Futsal Players.

ABSTRACT: Spyrou, K, Alcaraz, PE, Marín-Cascales, E, Herrero-Carrasco, R, Cohen, DD, Calleja-Gonzalez, J, Pereira, LA, Loturco, I, and Freitas, TT. Effects of the COVID-19 lockdown on neuromuscular performance and body composition in elite futsal players. J Strength Cond Res 35(8): 2309-2315, 2021-Recent world events (i.e., COVID-19 pandemic) led to an unparalleled situation in sports. Players were forced to stay at home for a prolonged period and not allowed to use their team's training facilities or even exercise outdoors. The main aim of this study was to examine the effects of the COVID-19 lockdown on neuromuscular performance and body composition in futsal players. Ten elite male players performed a 10-m sprint, horizontal and vertical jump, and body composition measurements before and after the quarantine (i.e., 70 days). Pre-post confinement differences in horizontal jump distance, countermovement jump variables, sprinting time, and body composition were analyzed by a paired sample t-test and effect sizes (ESs). A large and significant decline was observed in sprint ability (p = 0.004; ES = 1.31). Small and nonsignificant differences were found in horizontal jump performance (p = 0.243; ES = -0.39). Nonsignificant differences were observed in countermovement jump (CMJ) height (p = 0.076; ES = -0.63) but moderate-to-large significant declines were found in CMJ eccentric deceleration impulse, rate of force development, peak power, velocity, and landing peak force (p ≤ 0.05; ES = -0.52 - 1.23). Finally, trivial and nonsignificant differences were obtained on body composition parameters. In summary, sprint performance and specific CMJ kinetic variables were significantly affected by long-term reduced training, whereas vertical jump height and horizontal jump distance and body composition were not. Practitioners are advised to implement efficient sprint-oriented and eccentric-oriented training strategies to optimize return to competition after prolonged detraining periods.

Minimal Stabilization Time for Ultra-short Heart Rate Variability Measurements in Professional Soccer.

The main aims of this study were: 1) to compare 1-minute RMSSD measurements using different stabilization times between them and also with the criterion; and 2) to determine the agreement between every 1-minute RMSSD measurement with the criterion in professional soccer players. Seven hundred eighteen HRV measurements from professional soccer players were taken. HRV was calculated from 5 to 10 minutes (criterion) and from 1-minute windows with different pre-stabilization times. Friedman and post-hoc tests were applied to compare 1-minute and criterion measurements. Effect size was considered to describe magnitude of change. To determine agreement, Spearman's correlation was applied, and Bland-Altman analysis was also done between each ultra-short HRV time window and the 5-minute HRV criterion period. The 1-minute HRV without any pre-stabilization time was the only one different from all the other 1-minute measurements that included 1 or more minutes of pre-stabilization (p<0.001). One-minute HRV measurements with 1 or more minutes of pre-stabilisation were highly correlated with those for the criterion period. One-minute HRV without pre-stabilization showed the lowest correlation and the highest bias from the criterion. It is concluded that 1-minute HRV measurements with a prior 1-minute or longer pre-stabilization time are valid to measure HRV in professional male soccer players.

Relationship Between Bench Press Strength and Punch Performance in Male Professional Boxers.

López-Laval, I, Sitko, S, Muñiz-Pardos, B, Cirer-Sastre, R, and Calleja-González, J. Relationship between bench press strength and punch performance in male professional boxers. J Strength Cond Res 34(2): 308-312, 2020-This study investigated the relationship between punching performance and the velocity at which different loads were lifted during the bench press (BP) exercise in 12 professional boxers (age = 22.6 ± 4 years; height = 177.7 ± 5 cm; body mass 70.6 ± 6.43 kg; years of boxing experience = 6.5 ± 3.5 years; weight class = from light to super welterweight). To determine the maximal punching velocity (PVmax) during both rear arm (RA) and lead arm (LA) punching, an accelerometer (Crossbow; Willow Technologies, Sussex, United Kingdom) was placed inside the boxing glove while executing 3 jabs at a maximal velocity with each arm. Upper-body strength was assessed through the direct 1-repetition maximum (1RM) BP test, and the maximum velocity at different percentages of 1RM was obtained with a linear encoder. The main finding was that RA PVmax was correlated with the BP velocity at all submaximal intensities (p < 0.05). Nevertheless, LA PVmax did not correlate with BP velocity at any intensity. When the correlated BP submaximal intensities were introduced in linear regression models, the velocity at 80% 1RM was the only predictor of RA PVmax (r = 0.75; p < 0.01) in professional boxers. Additional body mass adjustment to the regression model significantly affected the predictive value (r = 0.65; p < 0.005). Results encourage coaches and trainers to use BP exercise with high loads (i.e., 80% of 1RM) because this could be a reliable predictor of performance during the specific boxing action. Future research is needed to determine exercises and intensities that could explain LA PVmax because significant associations were not found.

Short-term optimal load training vs a modified complex training in semi-professional basketball players.

This study investigated the effects on neuromuscular performance of a 6-week Optimal Load Training (OLT) and a novel modified Complex Training (MCT) (complex pairs: the same exercise using a moderate and an OL) in basketball players, in-season. Eighteen male athletes were randomly assigned to one of the protocols. Anthropometric measurements were taken to evaluate body composition. Lower- and upper-body maximum dynamic strength, countermovement jump (CMJ), standing long jump (SLJ), 10-m sprint and change of direction (COD) were also assessed. Moderate-to-large strength gains (presented as percentage change ± 90% confidence limits) were obtained for half-squat (OLT: 10.8 ± 5.3%; MCT: 17.2 ± 11.6%) and hip thrust (OLT: 23.5 ± 17.7%; MCT: 28.2 ± 19.0%). OLT athletes achieved likely small improvements in sprint (1.6 ± 1.6%) and COD (3.0 ± 3.2%). Players in the MCT attained likely moderate improvements in COD (3.0 ± 2.0%) and possibly small in SLJ (2.5 ± 4.6%). No protocol relevantly affected CMJ or body composition. An ANCOVA test revealed unclear between-group differences. In conclusion, both protocols increased basketball players' strength without the use of heavy loads (> 85% 1RM) and without impairing sprint, CMJ and SLJ performance. These findings suggest that basketball strength and conditioning professionals may use either method to counteract strength losses during the season.

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.

Accuracy of a Basketball Indoor Tracking System Based on Standard Bluetooth Low Energy Channels (NBN23®).

The present study aims to identify the accuracy of the NBN23® system, an indoor tracking system based on radio-frequency and standard Bluetooth Low Energy channels. Twelve capture tags were attached to a custom cart with fixed distances of 0.5, 1.0, 1.5, and 1.8 m. The cart was pushed along a predetermined course following the lines of a standard dimensions Basketball court. The course was performed at low speed (<10.0 km/h), medium speed (>10.0 km/h and <20.0 km/h) and high speed (>20.0 km/h). Root mean square error (RMSE) and percentage of variance accounted for (%VAF) were used as accuracy measures. The obtained data showed acceptable accuracy results for both RMSE and %VAF, despite the expected degree of error in position measurement at higher speeds. The RMSE for all the distances and velocities presented an average absolute error of 0.30 ± 0.13 cm with 90.61 ± 8.34 of %VAF, in line with most available systems, and considered acceptable for indoor sports. The processing of data with filter correction seemed to reduce the noise and promote a lower relative error, increasing the %VAF for each measured distance. Research using positional-derived variables in Basketball is still very scarce; thus, this independent test of the NBN23® tracking system provides accuracy details and opens up opportunities to develop new performance indicators that help to optimize training adaptations and performance.

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.

Evaluation of Basketball-Specific Agility: Applicability of Preplanned and Nonplanned Agility Performances for Differentiating Playing Positions and Playing Levels.

Sekulic, D, Pehar, M, Krolo, A, Spasic, M, Uljevic, O, Calleja-González, J, and Sattler, T. Evaluation of basketball-specific agility: applicability of preplanned and nonplanned agility performances for differentiating playing positions and playing levels. J Strength Cond Res 31(8): 2278-2288, 2017-The importance of agility in basketball is well known, but there is an evident lack of studies examining basketball-specific agility performances in high-level players. The aim of this study was to determine the reliability and discriminative validity of 1 standard agility test (test of preplanned agility [change-of-direction speed] over T course, T-TEST), and 4 newly developed basketball-specific agility tests, in defining playing positions and performance levels in basketball. The study comprised 110 high-level male basketball players (height: 194.92 ± 8.09 cm; body mass: 89.33 ± 10.91 kg; age: 21.58 ± 3.92 years). The variables included playing position (Guard, Forward, Center), performance level (first division vs. second division), anthropometrics (body height, body mass, and percentage of body fat), T-TEST, nonplanned basketball agility test performed on dominant (BBAGILdom) and nondominant sides (BBAGILnond), and a preplanned (change-of-direction speed) basketball agility test performed on dominant (BBCODSdom) and nondominant sides (BBCODSnond). The reliability of agility tests was high (intraclass correlation coefficient of 0.81-0.95). Forwards were most successful in the T-TEST (F test: 13.57; p = 0.01). Guards outperformed Centers in BBCODSdom, BBCODSndom, BBAGILdom, and BBAGILnond (F test: 5.06, p = 0.01; 6.57, 0.01; 6.26, 0.01; 3.37, 0.04, respectively). First division Guards achieved better results than second division Guards in BBCODSdom (t: 2.55; p = 0.02; moderate effect size differences), BBAGILdom, and BBAGILnond (t: 3.04 and 3.06, respectively; both p = 0.01 and moderate effect size differences). First division Centers outperformed second division Centers in BBAGILdom (t: 2.50; p = 0.02; moderate effect size differences). The developed basketball-specific agility tests are applicable when defining position-specific agility. Both preplanned and nonplanned agilities are important qualities in differentiating between Guards of 2 performance levels. The results confirmed the importance of testing basketball-specific nonplanned agility when evaluating the performance level of Centers.

Acute Effects of Two Different Resistance Circuit Training Protocols on Performance and Perceived Exertion in Semiprofessional Basketball Players.

This study aimed to investigate the acute effects of two different resistance circuit training protocols on basketball players' physical and technical performance and rating of perceived exertion (RPE). In a repeated-measures, crossover experimental design, 9 semiprofessional basketball players performed a Power Circuit Training (PCT; 45% 1RM) and a High-Resistance Circuit Training (HRC; 6RM), on consecutive weeks. Vertical and horizontal jump performance, 3-points shooting accuracy, repeated-sprint ability (RSA), agility, and upper body power output were measured before and after training. The RPE was assessed 20 minutes after resistance training. One-way repeated-measures analysis of variance showed performance decrements in vertical jump height and peak power, horizontal jump distance, 3-points percentage, bench-press power output, RSA total and ideal time, and agility T-Test at total time following HRC, but not PCT (p ≤ 0.05). The RPE was higher in HRC compared with PCT. The results of this study indicated that HRC was perceived as being harder and produced higher fatigue levels, which in turn lowered acute performance. However, low-to-moderate intensity loads did not negatively affect performance. Thus, completing a PCT session may be the most appropriate option before a practice or game as it avoids acute-resistance-training-induced performance decrements. However, if the objective of the basketball session is to develop or perfect technical skills during fatiguing conditions, HRC may be the more suitable option.

Using testosterone and cortisol as biomarker for training individualization in elite basketball: a 4-year follow-up study.

The purpose of this study was to determine the responses of testosterone and cortisol, with special reference to playing positions, playing time (PT), and phase of the season. We performed a follow-up study during 4 consecutive seasons to investigate the effects of PT, positional role, and phase of the season on anabolic-catabolic biomarkers (plasma total testosterone -TT- and cortisol -C-) on 20 professional male basketball players (27.0 ± 4.2 years; 24.4 ± 1.2 kg·m). First blood samples were collected right after the off-season period and considered as baseline. Samples were taken periodically every 4-6 weeks, always after a 24- to 36-hour break after the last game played. Statistical procedures were nonparametric mainly. Hormonal status was playing position-dependent, power forward (PF) showed the lowest TT values (median ± interquartile range [IQR]; PF: 18.1 ± 4.9; nmol·L), and small forwards showed the highest ones of cortisol (0.55 ± 0.118 µmol·L). Players who played between 13 and 25 minutes per game showed the highest values of TT (22.8 ± 6.9 nmol·L) and TT/C (47.1 ± 21.2). March and April showed the most catabolic or stressed hormonal state (low TT/C values and high ones of cortisol) and that is necessary to take into account according to PT (>25-minute per game) and specific playing position. Monitoring plasma TT and cortisol is recommended to prevent excessive stress caused by professional basketball season requirements.

Compression stockings do not improve muscular performance during a half-ironman triathlon race.

PURPOSE: This study aimed at investigating the effectiveness of compression stockings to prevent muscular damage and preserve muscular performance during a half-ironman triathlon. METHODS: Thirty-six experienced triathletes volunteered for this study. Participants were matched for age, anthropometric data and training status and placed into the experimental group (N = 19; using ankle-to-knee graduated compression stockings) or control group (N = 17; using regular socks). Participants competed in a half-ironman triathlon celebrated at 29 ± 3 °C and 73 ± 8% of relative humidity. Race time was measured by means of chip timing. Pre- and post-race, maximal height and leg muscle power were measured during a countermovement jump. At the same time, blood myoglobin and creatine kinase concentrations were determined and the triathletes were asked for perceived exertion and muscle soreness using validated scales. RESULTS: Total race time was not different between groups (315 ± 45 for the control group and 310 ± 32 min for the experimental group; P = 0.46). After the race, jump height (-8.5 ± 3.0 versus -9.2 ± 5.3%; P = 0.47) and leg muscle power reductions (-13 ± 10 versus -15 ± 10 %; P = 0.72) were similar between groups. Post-race myoglobin (718 ± 119 versus 591 ± 100 µg/mL; P = 0.42) and creatine kinase concentrations (604 ± 137 versus 525 ± 69 U/L; P = 0.60) were not different between groups. Perceived muscle soreness (5.3 ± 2.1 versus 6.0 ± 2.0 arbitrary units; P = 0.42) and the rating of perceived effort (17 ± 2 versus 17 ± 2 arbitrary units; P = 0.58) were not different between groups after the race. CONCLUSION: Wearing compression stockings did not represent any advantage for maintaining muscle function or reducing blood markers of muscle damage during a triathlon event.

Relationship between physiological parameters and performance during a half-ironman triathlon in the heat.

Triathlon is a popular outdoor endurance sport performed under a variety of environmental conditions. The aim of this study was to assess physiological variables before and after a half-ironman triathlon in the heat and to analyse their relationship with performance. Thirty-four well-trained triathletes completed a half-ironman triathlon in a mean dry temperature of 29 ± 3ºC. Before and within 1 min after the end of the race, body mass, core temperature, maximal jump height and venous blood samples were obtained. Mean race time was 315 ± 40 min, with swimming (11 ± 1%), cycling (49 ± 2%) and running (40 ± 3%) representing different amounts of the total race time. At the end of the competition, body mass changed by -3.8 ± 1.6% and the change in body mass correlated positively with race time (r = 0.64; P < 0.001). Core temperature increased from 37.5 ± 0.6ºC to 38.8 ± 0.7ºC (P < 0.001) and post-race core temperature correlated negatively with race time (r = -0.47; P = 0.007). Race time correlated positively with the decrease in jump height (r = 0.38; P = 0.043), post-race serum creatine kinase (r = 0.55; P = 0.001) and myoglobin concentrations (r = 0.39; P = 0.022). In a half-ironman triathlon in the heat, greater reductions in body mass and higher post-competition core temperatures were present in faster triathletes. In contrast, slower triathletes presented higher levels of muscle damage and decreased muscle performance.

The biological age of 14-year-old boys and success in adult soccer: do early maturers predominate in the top-level game?

Talent identification and development in soccer is often biased by maturation-related differences of young athletes. However, there is no information available about success rates for youth maturing at different tempos to achieve success in elite adult soccer. The purposes of this study were to determine the prevalence of different maturational groups among boys playing soccer, and to track them for competence in adult performance. A prospective cohort study design was used to follow 55, 14-year-old boys playing in Serbian youth soccer Division I over eight years. At the age of 14, biological age using skeletal age rates was determined, and participants were categorized as early maturers (EaM), normal maturers (NoM), and late maturers (LaM). Game competence for adult soccer at age 22 was described as elite if an individual played for clubs competing in top-five international soccer leagues (La Liga, Premier League, Bundesliga, Serie A, and Ligue 1), and/or has become a member of an adult National team. Among boys in our study group, 43.8% were categorized as EaM, 35.4% as NoM, and 20.8% as LaM (P = 0.11). A significant difference in biological age was found among maturational groups at age 14, with EaM > NoM > LaM (P > 0.0001). When assessed for adult soccer competence, 33.3% of participants (16 out of 48 players) succeed in achieving elite level. Elite soccer competence acquired 60.1% players from the group of LaM, 38.1% from NoM, and 11.8% from EaM (P > 0.0001). Our comparative analysis suggests that soccer excludes early maturing boys and favors late maturing boys as level of performance increases.