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Background: Monitoring training load and competition load is crucial for evaluating and improving athlete performance. This study proposes an applied approach to characterize and classify the training task specificity in relation to competition in a top-level rink hockey team, considering external and internal load from training tasks and competition.Hypothesis: Training tasks and game demands have significant dose-response differences, and exercises can be classified successfully based on their physiological and biomechanical demands.Study Design: Cross-sectional study.Level of Evidence: Level 5.Methods: Ten elite-level male rink hockey players participated in this study. Players were monitored on 6 different task categories during 8 training sessions and 2 official games. A linear mixed model with random intercepts was used to compare training tasks and competition load, accounting for individual repeated measures. A 2-step cluster analysis was performed to classify the training tasks and games based on physiological and biomechanical load, employing log-likelihood as the distance measure and Schwartz’s Bayesian criterion.Results: Average heartrate, maximum heartrate, and high-speed skating (18.1-30 km/h) were the best physiological load predictors, while the most effective biomechanical load predictors were impacts [8-10] g(n), decelerations [-10 to -3]m/s²(n), and accelerations [3-10]m/s²(n). Different physiological and biomechanical responses were verified between training tasks and match demands. A 4-quadrant efforts assessment for each task category revealed that training tasks used by the team in the analysis presented lower biomechanical and physiological load demands than competition.Conclusion: Training tasks failed to adequately replicate the specific demands of competition, especially regarding high mechanical stress, such as the absence of high-intensity impacts and decelerations.Clinical Relevance: This method of classification of training tasks may allow coaches to understand further the specificity and contribution of each task to competition demands, consequently improving the capacity of load management and the preparedness and readiness of players for competition.

ABSTRACTThis study aimed to describe the current practices in futsal regarding a variety of topics related to performance and injury risk mitigation. Thirty-seven coaches from Spain and Portugal completed a questionnaire consisting of 28 closed questions organized in four categories: a) background information; b) training load (TL) monitoring and assessment of players’ physical qualities; c) strength training (ST) practices; and d) recovery (REC) methods. The results showed that coaches varied in experience (1–8 years) and age (from 20 years to >50 years). Overall, 97.3% of the participants declared monitoring TL, with rating of perceived exertion, heart rate monitors, and wearable technology being used by 86.5%, 40.5%, and 37.8%, respectively. Neuromuscular and strength testing are the most common practices to evaluate performance and fatigue during the season. ST is a significant component of futsal, being performed 3 times/week during the pre- and in-season. ST is prescribed via %1RM – XRM (59.5%), velocity-based training (21.7%), repetitions in reserve (18.9%), until failure (10.8%), and circuit training (2.7%). ‘Better Monitoring’, ‘More Individualized’, ‘Better Facilities’, ‘More Staff’, and ‘More Time’ were the main aspects to improve ST. Multiple post-match REC strategies are used, with durations ranging from 0–15 to 16–30 min independently of game location.

Spyrou, K, Alcaraz, PE, Marín-Cascales, E, Herrero-Carrasco, R, Cohen, DD, and Freitas, TT. Neuromuscular performance changes in elite futsal players over a competitive season. J Strength Cond Res37(5): 1111–1116, 2023—A professional futsal season imposes a great amount of physiological and mechanical stress on players. The main aim of this study was to examine the changes in neuromuscular performance qualities across the season. Ten professional male players performed a 10-m sprint, standing long jumps (SLJs), and countermovement jumps (CMJs) during the competitive season (i.e., every ∼5 weeks from September to January). A one-way repeated measures ANOVA with post hoc pairwise comparisons and effect sizes (ESs) were used to analyze potential differences among these assessments. A significant and large decline was found in concentric peak power (p= 0.040; ES = 1.24). A nonsignificant and moderate decrease was observed in sprint ability (p= 0.155; ES = 1.03), CMJ height (p= 0.175; ES = 1.00), and SLJ distance (p= 0.164; ES = 1.03). Regarding other CMJ kinetic variables, nonsignificant and moderate changes were found. In summary, considering the neuromuscular performance tests and variables assessed, only concentric peak power in CMJ decreased significantly across the season; however, nonsignificant decrements were observed in sprinting time, SLJ, CMJ height, and other kinetic metrics. CMJ variables during the jump-land cycle should be incorporated alongside more traditional measures (e.g., jump height) to monitor performance during the season.

Freitas, TT, Pereira, LA, Alcaraz, PE, Cadore, EL, Grazioli, R, Azevedo, PHSM, Jeffreys, I, and Loturco, I. Interrelationships between multiple speed tests in youth soccer: Are players equally efficient at performing different sprint and COD tasks? J Strength Cond Res37(4): 848–853, 2023—We investigated the relationships between linear and multidirectional sprint tests in elite young soccer players, using different speed measurements and their associated deficits. Twenty-three under-17 and 17 under-16 soccer players performed, on the same day, 17-m linear sprint (with 10-m split times), curve sprints for “good” and “weak” sides (CSGS and CSWS, respectively), and zigzag and 505 change of direction (COD) tests. The Pearson’s product moment test was used to determine the relationships among the tested variables. Significance level was set at p< 0.05. Large and very large significant correlations were observed between CSGS and CSWS and 10-m (r= 0.73 and r= 0.53, respectively; p< 0.0001) and 17-m sprint velocity (r= 0.84 and r= 0.74, respectively; p< 0.0001). Moderate and significant associations were identified between zigzag and 17-m sprint performances (r= 0.40; p= 0.02). No significant relationships were found between 505 performance and 17-m sprint velocity and between the different COD tasks (p> 0.05). Significant correlations were observed between sprint performance at 10- and 17-m and both CS and COD deficits (rvalues ranging from 0.37 to 0.54; p< 0.05). In general, higher linear sprinting velocities were associated with superior performances in smoother multidirectional tasks (i.e., CS and zigzag tests) but not in more aggressive COD maneuvers (i.e., 505). Faster athletes in linear actions presented greater CS and COD deficits. No associations were detected between the different COD measurements, supporting the notion that the technical and mechanical demands of COD actions are angle and velocity dependent. From a practical perspective, comprehensive speed testing batteries (i.e., incorporating linear sprints, CS, and different COD assessments) should be administered to young soccer players, to better understand their ability to change direction and sprint over multiple trajectories.

Ferioli, D, Conte, D, Rucco, D, Alcaraz, PE, Vaquera, A, Romagnoli, M, and Rampinini, E. Physical demands of elite male and female 3×3 international basketball matches. J Strength Cond Res37(4): e289–e296, 2023—This study aimed to (1) characterize the physical demands of 3 × 3 basketball games during live playing time and ball possession and (2) assess the differences in physical demands between male and female players. Following an observational design, video footage from 27 games of the International Basketball Federation 3 × 3 World Cup 2019 were analyzed from 104 international 3 × 3 basketball players (n= 52 male and n= 52 female players) resulting in a total of 216 (104 male and 112 female) individual game samples. Manual frame-by-frame time-motion analyses determined the relative frequency (n·min−1) and duration (%) for several physical demands at different intensities, according to sex, during the live playing time and in ball possession phases. Linear mixed models for repeated measures and effect size (ES) analyses revealed smallnon-significant differences in the intermittent profile of 3 × 3 basketball games according to sex (total movements per minute, male = 39.3 (38.6–40.1); female = 40.2 (39.5–41.0), estimated marginal means with 95% confidence intervals). Female competitions had significantly greater number of low-intensity activities (LIA, smallES) and high-intensity activities (HIA, smallES) performed per minute over longer games (smallES), whereas male players had more recovery activities (smallES). During ball possession, male players spent a larger amount of time performing LIA (smallES) than female players, who displayed both the greatest number of HIA and the highest percentage of playing time performed at high intensity (smallES). Overall, these findings suggest that basketball coaches should design sex-specific training sessions based on the specific match demands.

Supplemental Digital Content is Available in the Text.Martínez-Serrano, A, Freitas, TT, Franquesa, X, Enrich, E, Mallol, M, and Alcaraz, PE. Does external load reflect acute neuromuscular fatigue and rating of perceived exertion in elite young soccer players? J Strength Cond Res37(3): e1–e7, 2023—This study aimed to analyze the acute and residual effects of increased high-speed running (HSR) demands during an in-season training microcycle in young elite soccer players on localized neuromuscular fatigue (NMF) of the knee extensors (KE), posterior chain muscles, and rating of perceived exertion (RPE). Thirty-four elite young soccer players (age = 17.1 ± 0.8 years) were assessed in 2 consecutive days at different time points (baseline, POST-activation gym-based session, POST–small-sided game [SSG], POST-training 1 [TR1], POST-6H, POST-24H, POST-preventive gym-based session, and POST-training 2 [TR2]). Neuromuscular fatigue of the KE and posterior chain muscles was measured with a maximum voluntary isometric contraction (MVIC). External (total distance, number of accelerations or decelerations, and HSR distance) and internal (RPE) load was assessed during the SSG, TR1, and TR2 sessions. Players were divided through a median split, into “HIGH” or “LOW” group according to the training demands. The alpha level was set at p≤ 0.05. A 2-way mixed effects model ANOVA showed a significant decreased in 90:20 MVIC after TR1 in the “HIGH” HSR group (p= 0.037; effect size [ES] = 0.45). No significant differences in RPE were found after TR1 (p= 0.637; ES = 0.58) and TR2 (p= 0.109; ES = 0.62) when comparing the “HIGH” HSR group with the “LOW” HSR group. Assessing player's force production capabilities can be an effective strategy to detect NMF when HSR demands are acutely increased. Special caution should be taken when prescribing the training load of the training session based solely on RPE, as NMF might be present.

Sprinting is a key component for many individual and team sports. Therefore, to enhance sprint performance, various training methods are widely used by coaches and practitioners, including maximum sprint speed and resisted sprint training. Resisted sprinting with sled towing is a method that has recently received considerable attention from the sport science community. However, to date, no consensus exists regarding its acute and chronic effects in team sport athletes. This narrative review aimed to (a) review and analyze the mechanics of sprinting under unresisted and resisted conditions with a specific focus on team sport disciplines; (b) provide a thorough and applied discussion on the importance of considering acute and chronic effects of sled loading on technique, electromyographic activity, and force production, as well as on the role of muscle architecture and neural factors in sled training; (c) analyze the effects of increasing sled loads during acceleration and maximum velocity phases on contact and flight phases, while concomitantly examining kinetic, kinematic, and neuromuscular aspects, because all these factors affect each other and cannot be properly understood in isolation.

Freitas, TT, Pereira, LA, Alcaraz, PE, Azevedo, PHSM, Bishop, C, and Loturco, I. Percentage-based change of direction deficit: a new approach to standardize time- and velocity-derived calculations. J Strength Cond Res36(12): 3521–3526, 2022—Change of direction (COD) efforts are crucial in team sports, and an extensive body of research has been devoted to investigating this complex and multifaceted skill. Most studies have assessed players' ability to change direction by reporting completion time or average velocity in different COD tasks. However, it has been argued that these variables may not accurately portray an athlete's true capability to quickly change direction. In this context, new metrics such as the COD Deficit (CODD) have been proposed to provide complementary information on the efficiency to change direction. The current literature presents 2 different CODD computations: time-derived and velocity-derived calculations. Despite both being consistent and representing the same phenomenon, the decision of using one or the other may produce different outcomes, thus influencing coaches' decisions and training strategies. To overcome this issue, we propose a new approach to the computation of the CODD, based on the difference in percentage between linear sprint and COD abilities, in an attempt to standardize the estimation of this variable and simplify the evaluation of COD performance.

Supplemental Digital Content is Available in the Text.Zabaloy, S, Carlos-Vivas, J, Freitas, TT, Pareja-Blanco, F, Loturco, I, Comyns, T, Gálvez-González, J, and Alcaraz, PE. Muscle activity, leg stiffness and kinematics during unresisted and resisted sprinting conditions. J Strength Cond Res36(7): 1839–1846, 2022—This study aimed to compare muscle activity, leg stiffness, and kinematics (contact and flight time [FT], stride length and frequency, and trunk angle [TA]) of unloaded sprinting to resisted sprint (RST) using different loads. Twelve male rugby players (age: 23.5 ± 5.1 years; height: 1.79 ± 0.04 m; body mass 82.5 ± 13.1 kg) performed 30-m sprints using different loading conditions (0, 10, 30 and 50% of velocity loss—Vloss—from the maximum velocity reached under unloaded condition). Muscle activity from 4 muscles (biceps femoris long head, rectus femoris [RF], gluteus medius and gastrocnemius), leg stiffness (Kleg), and kinematics were measured during the acceleration and maximum velocity (Vmax) phases of each sprint. Heavier loads led to significantly lower biceps femoris long head activation and higher rectus femoris activity (p< 0.01–0.05). Significant reductions in Klegwere observed as loading increased (p< 0.001–0.05). Kinematic variables showed substantial changes with higher loads during the acceleration and Vmax phase. In conclusion, the heavier the sled load, the higher the disruptions in muscle activity, Kleg, and kinematics. When coaches and practitioners intend to conduct resisted sprint training sessions without provoking great disruptions in sprint technique, very-heavy sled loads (greater than 30% Vloss) should be avoided. However, heavy sled loads may allow athletes to keep specific positions of the early acceleration phase for longer time intervals (i.e., first 2–3 strides during unresisted sprints).

Pareja-Blanco, F, Pereira, LA, Freitas, TT, Alcaraz, PE, Reis, VP, Guerriero, A, Arruda, AFS, Zabaloy, S, De Villarreal, ES, and Loturco, I. Acute effects of progressive sled loading on resisted sprint performance and kinematics. J Strength Cond Res36(6): 1524–1531, 2022—We examined the effects of 5 loading conditions (0, 20, 40, 60, and 80% of body-mass [BM]) on resisted sprint performance and kinematics in male rugby players over different distances. Ten players from the Brazilian National Team (20.1 ± 3.3 years; 88.7 ± 18.8 kg; 178.3 ± 6.2 cm) performed 20-m sprints under the 5 loading conditions. Sprint times in 5, 10, and 20 m were recorded. Stride length (SL), and hip, knee, and ankle angles were measured using an eight-sensor motion analysis system. The kinematic parameters were calculated over the different distances. Heavier loads led to significantly greater velocity loss (p< 0.001–0.05). Significant reductions in SL were also observed when comparing 0% BM and all resisted sprints in all assessed distances (p< 0.001–0.05, effect size [ES]: 1.35–4.99). Very heavy (80% BM) sled load provoked significantly greater decreases in SL than the rest of loading conditions (p< 0.01–0.05). Important kinematic alterations were observed for all loading conditions and sprint distances when compared with 0% BM (ES: 0.76–1.79, for hip-angle; 0.20–1.40, for knee-angle; and 0.73–1.88, for ankle-angle). Moreover, 80% BM induced significantly higher hip flexion, lower knee flexion, and higher ankle dorsiflexion than 20% BM condition at 5–10 and 10–20 m distances (p< 0.05). Lighter sled loads (<40% BM) seem to be more adequate to improve speed ability without provoking drastic changes in the unloaded sprinting technique, whereas heavier loads may be more suitable for optimizing horizontal force production and thus, acceleration performance.

•Heart rate variability can serve as a monitoring tool for cardiac autonomic stress recovery after acute resistance exercise.•Cardiac sympathetic modulation predominates following an acute resistance exercise session.•Training volume (number of sets, intensity) and rest between sets are important moderating factors on heart rate variability parameters following an acute resistance training session.

Zabaloy, S, Giráldez, J, Fink, B, Alcaraz, PE, Pereira, LA, Freitas, TT, and Loturco, I. Strength deficit in elite young rugby players: Differences between playing positions and associations with sprint and jump performance. J Strength Cond Res36(4): 920–926, 2022—The aims of this study were twofold: to compare the strength-related performance between young forwards and backs rugby players and to examine the correlations between strength deficit (SDef), strength parameters, and sprint and jump performance. Fifty-seven male rugby players (mean ± SD: age, 17.4 ± 1.3 years) performed anthropometric and body composition assessments, vertical jumps, 30-m sprint, and squat (SQ) and bench press (BP) 1-repetition maximum tests (1RM SQ and BP). The differences in the tested variables between positions were analyzed through an independent t-test. A Pearson’s correlation coefficient was used to assess the relationships among the variables. Significant differences were observed for anthropometric and body composition measures and jump and sprint performance between positions (p< 0.05; effect size [ES]: 0.60–1.34), except for 5-m velocity (p= 0.080; ES: 0.57). Backs demonstrated higher relative 1RM than forwards in both exercises (p= 0.009 and p= 0.008; ES = 0.88 and 0.91, for SQ and BP, respectively). In addition, backs demonstrated lower SDef from 70 to 90% 1RM (p< 0.048) but small-to-moderate nonsignificant lower SDef against lighter loads compared with forwards (50–60% 1RM). Overall, SDef across all loads (r: −0.378 to −0.529) and 1RM SQ (r: 0.504 to −0.590) were significantly related to sprint performance. Therefore, young rugby players who present lower magnitudes of SDef and superior 1RM SQ performance tend to be faster in linear sprints.

ABSTRACTObjectiveRecognizing the high stakes associated with winning and losing in the National Basketball Association (NBA), a deep understanding of the underlying mechanisms of NBA game-play performance would provide substantial benefit to all stakeholders involved with preparing NBA players and teams for competitive success. To the best of the authors’ knowledge, this systematic review presents the first attempt to systematically amalgamate and appraise the scientific literature published in the XXI Century, following a constraints-led approach (CLA). In particular, two underpinning factors of NBA game-play performance were investigated: (1) NBA player constraints (internal variables) and (2) NBA contextual constraints (external variables).MethodsDatabases included PubMed (MEDLINE), Web of Science (WOS), ResearchGate, SPORTDiscus, SCOPUS, Google Scholar, and the World Association of Basketball Coaches’ database (WABC). This review followed the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) model and the Population, Intervention, Comparison and Outcomes (PICOS) guidelines.ResultsUltimately, 43 articles met the inclusion criteria (n = 43). Promisingly, the vast majority of studies were published in recent years (>2016; n = 28; 65.1%). Topics related to ‘contextual constraints’ (n = 25; 58.1%) received more attention than topics related to ‘player constraints’ (n = 18; 41.9%). Even though the importance of longitudinal-interventional approaches to applied sports science is well-documented, descriptive-observational research emerged as the most popular method of choice (n = 27; 62.8%); interventional studies were absent; and near all researchers merely utilized secondary data sources (n = 37; 86.0%).ConclusionsTaking into account the total body of evidence (2001–2020), NBA practitioners may use this systematic review as a baseline reference to enrich their current knowledge about the nature, demands, and dynamics of the modern-day NBA ecosystem. Finally, adoption of an ‘Applied Science Research Framework’ is encouraged, fostering clearly outlined project incentives; standardizing taxonomies; sequencing follow-up studies; embracing holistic and cross-disciplinary viewpoints; and integrating longitudinal-interventional projects to increase the reproducibility of their findings.

Freitas, TT, Pereira, LA, Alcaraz, PE, Comyns, TM, Azevedo, PHSM, and Loturco, I. Change-of-direction ability, linear sprint speed, and sprint momentum in elite female athletes: differences between three different team sports. J Strength Cond Res36(1): 262–267, 2022—The aim of this study was to compare the performance of elite female players from 3 different sports in linear sprint and change-of-direction (COD) tests and examine their efficiency for changing direction through the calculation of the COD deficit (i.e., the difference in velocity between a linear sprint and a COD task of equal distance). One hundred fifty-four elite players (rugby, n= 40, national team members; soccer, n= 57 and handball n= 57, first division players from the respective Brazilian National Championships) were assessed in the 20-m linear sprint and Zigzag COD tests. A one-way analysis of variance with a Tukey post hoc was used to detect between-sport differences. Female rugby sevens players achieved faster sprint velocities than handball (20‐m: 6.21 ± 0.24 m·s−1; 6.07 ± 0.27 m·s−1, respectively; p< 0.05) and soccer players (5‐m: 4.71 ± 0.26 m·s−1vs. 4.51 ± 0.20 m·s−1; and 20‐m: 6.08 ± 0.19 m·s−1; p< 0.05) and exhibited the greatest COD deficits (2.95 ± 0.25 m·s−1; 2.69 ± 0.19 m·s−1; 2.82 ± 0.17 m·s−1, for rugby, handball, and soccer, respectively; p< 0.05). Handball players outperformed all other athletes in the Zigzag test (3.38 ± 0.15 m·s−1; 3.26 ± 0.10 m·s−1; 3.26 ± 0.10 m·s−1, for handball, rugby, and soccer, respectively; p< 0.05) but presented the lowest COD deficits (p< 0.05). Furthermore, soccer players displayed inferior sprint momentum when compared with the other sports (p< 0.05). Linear sprint and COD ability differ significantly among elite female athletes from different team sports, with handball players exhibiting a greater COD speed and efficiency to change direction, with respect to their maximum sprint velocity. The between-sport differences observed suggests that specific training and game demands may affect both sprint and COD performance.

•Football (soccer) practice is associated with the risk of injuries.•Injury prevention can be addressed from a biomechanical, psychosocial, psychological and physical exercise perspective.•Effective injury prevention programs that focus on physical exercise interventions are presented in this review.

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 Res35(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 ttest, 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 likelyto almost certainlysignificantly 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). Largesignificant relationships among COD velocities (rranging from 0.71 to 0.88; p< 0.05) and almost perfectsignificant correlations among all COD deficits (rranging 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.

Ramos-Campo, DJ, Martínez-Guardado, I, Rubio-Arias, JA, Freitas, TT, Othalawa, S, Andreu, L, Timón, R, and Alcaraz, PE. Muscle architecture and neuromuscular changes after high-resistance circuit training in hypoxia. J Strength Cond Res35(11): 3035–3040, 2021—This study aimed to analyze the effect of 8 weeks of high-resistance circuit (HRC) training in hypoxia on muscle architecture, strength, and neuromuscular variables. Twenty-eight resistance-trained subjects were assigned to a hypoxia (FiO2= 15%; HG: n= 15; age: 24.6 ± 6.8 years; height: 177.4 ± 5.9 cm; and mass: 74.9 ± 11.5 kg) or normoxia group (FiO2= 20.9%; NG: n= 13; age: 23.2 ± 5.2 years; height: 173.4 ± 6.2 cm; and mass: 69.4 ± 7.4 kg). Each training session consisted of 2 blocks of 3 exercises (block 1: bench press, leg extension, and front lat pulldown; block 2: deadlift, elbow flexion, and ankle extension). Each exercise was performed with a 6 repetition maximum load. Subjects exercised twice weekly and, before and after the training program, vastus lateralis muscle thickness and pennation angle, knee extensors electromyographic activity, maximum voluntary contraction (MVC), and rate of force development (RFD) and H-Reflex (Hmax), M-wave of the soleus muscle were assessed. Both training groups showed similar improvements in muscle thickness (effect size [ES] = HG: 0.23; NG: 0.41), pennation angle (ES = HG: 0.86; NG: 0.15), MVC (ES HG: 0.63; NG: 0.61), Hmax (ES = HG: 0.96; NG: 0.40), RFD at 200 milliseconds (ES = HG: 0.31; NG: 0.61) and peak RFD (ES = HG: 0.21; NG: 0.66). No significant between-group differences were found. In conclusion, similar morphological and neuromuscular adaptations can be achieved after 8 weeks of HRC training under hypoxic or normoxic conditions.

The aim of this study was to determine if heart rate variability (HRV) during incremental test could be used to estimate ventilatory threshold (VT) in professional basketball players, with sufficient precision to be used in their training. Furthermore, the second aim was to analyse the association between HRV and 3 methods of VT determination by gas analysis.

Recently, a pandemic disease (i.e., COVID-19) arose complicated conditions for players, clubs, and sports competitions. Most European countries postponed or canceled their respective leagues as players were forced into a long-term lockdown. This case study presents and compares the absolute and relative non-contact lower-limb injury rates and characteristics before and after the lockdown from a Finalist of the UEFA Futsal Champion League.

BackgroundLower limb posterior chain isometric peak force (IPF) measured in the supine position was found to be sensitive to match induced fatigue in footballers (McCall et al. 2015). However, hamstrings fatigue following simulated football may be greatest close to full knee extension (Cohen et al. 2014), and the majority of hamstring strains occur in an extended position (Mendiguchia et al. 2012).ObjectiveTo evaluate the effects of a simulated match on IPF in a novel test and a supine position test immediately post, and at +48 h, and +72 h post-match.DesignA within-subject, repeated-measures design was used to investigate the short-term effects of fatigue following a simulated football match-protocol –the BEASTmod904(Akubat et al. 2014).Participants17 semi-professional players (age 21.2±2.4 yrs, body mass 73.8±8.9 kg) competing in a Spanish Third-Division team volunteered to participate in the study, which was implemented after the end of their competitive season.InterventionsIPF was measured using a portable force platform immediately before (PRE) and after (POST) the BEASTmod90protocol, and at +48 h and +72 h post match. Two tests were used: (i) Standing with tested leg at 90° hip and 20° knee flexion (90:20); (ii) Supine with tested leg at 90° knee and hip flexion (S90).Main Outcome MeasurementsFatigue after a simulated football match-protocol. We hypothesized that the 90:20 would show greater levels of fatigue than the S90.ResultsIPF significantly declined PRE versus POST match in the 90:20 in both legs (p<0.001), and in the S90 in the non-dominant (p<0.001) and dominant leg (p<0.01). IPF was significantly lower at +48 h compared to PRE in the 90:20 in both legs (p<0.01, p≤0.05), but not in the S90. At +72 h, IPF was not significantly different from PRE in either test.ConclusionsThese findings suggest potential angle-specific differences in posterior chain fatigue following a simulated match, and that the 90:20 may be more sensitive to post competition residual posterior chain fatigue.