To examining the relationship between hip adductor strength and groin injury incidence during the competitive season of professional football teams. Prospective Cohort study. Controlled laboratory environment. Seventy-one players volunteered to participate. In the pre-season, maximal hip adductor strength was measured by means of the isometric adductor squeeze test. Hip adductor strength, normalized by body mass, was compared between players who suffered a groin injury (n = 18) vs uninjured players (n = 53). Risk ratios (RR) were used to evaluate the likelihood of players to suffer this type of injury. Most of the reported groin injuries occurred during competitive matches (5.5 per 1000 match hours). Maximal isometric hip adductor strength was lower in the groin-injured group compared with their uninjured counterparts (429.8 ± 100 vs 564 ± 58.7 N, d = -1.58 and 5.40 ± 1.27 vs 7.71 ± 0.89 N/kg, d = -1.88, respectively). Results revealed that values of maximal isometric adductor strength lower than 465.33 N increased the probability to suffer a groin injury by 72%. Furthermore, values of force relative to body mass lower than 6.971 N/kg increased the probability to suffer a groin injury by 83%. The assessment of Hip adductor strength, in addition to other measurements, might help practitioners to determine the probability of suffering an overuse groin injuries in elite football players.

The aim of this study was to investigate the acute (a football match) and chronic (a whole season) effects of competition on ankle dorsiflexion ROM in professional football players. Forty football players participated in this study. Ankle dorsiflexion ROM was recorded to examine acute (pre‐match, immediately post‐match and 48 h post‐match) and chronic (pre‐season, mid‐season and post‐season) effects of competitive football. In addition, it was found that players had restricted mobility measures on ankle dorsiflexion as >2 cm change between baseline measures (pre‐match and pre‐season). The training load of all played matches was estimated using a global positioning system (GPS) and RPE. Pre‐season ankle dorsiflexion ROM was greater compared to mid‐season (8.1% in the dominant, and 9.6% in the non‐dominant leg) and post‐season (13.8% in the dominant, and 12.5% in the non‐dominant leg). In addition, around 30% of all players showed restricted ankle dorsiflexion ROM values in post‐season compared with pre‐season. Related to acute effects, ankle dorsiflexion ROM increased after a match (5.8%) in the dominant ankle, and this value decreased (2.65%) 48 h post‐match when post‐match measurements in both dominant and non‐dominant ankles were compared. The progressive decrease in ankle dorsiflexion ROM throughout a season can be an indicator of increased risk of injury and may be reinforce the need of prevention actions such as stretching exercises and eccentric strength training in professional football players. In addition, these findings suggest to implement specific recovery strategies aiming at minimizing alteration in ankle dorsiflexion ROM 48 h post‐match.

Previous investigations have found that several genes may be associated with the interindividual variability to the ergogenic response to caffeine. The aim of this study is to analyze the influence of the genetic variations in CYP1A2 (−163C > A, rs762551; characterized such as “fast” (AA genotype) and “slow” caffeine metabolizers (C-carriers)) and ADORA2A (1976T > C; rs5751876; characterized by “high” (TT genotype) or “low” sensitivity to caffeine (C-carriers)) on the ergogenic response to acute caffeine intake in professional handball players. Thirty-one professional handball players (sixteen men and fifteen women; daily caffeine intake = 60 ± 25 mg·d⁻¹) ingested 3 mg·kg⁻¹·body mass (bm) of caffeine or placebo 60 min before undergoing a battery of performance tests consisting of a countermovement jump (CMJ), a sprint test, an agility test, an isometric handgrip test, and several ball throws. Afterwards, the handball players performed a simulated handball match (2 × 20 min) while movements were recorded using inertial units. Saliva samples were analyzed to determine the genotype of each player for the −163C > A polymorphism in the CYP1A2 gene (rs762551) and for the 1976T > C polymorphism in the ADORA2A gene (rs5751876). In the CYP1A2, C-allele carriers (54.8%) were compared to AA homozygotes (45.2%). In the ADORA2A, C-allele carriers (80.6%) were compared to TT homozygotes (19.4%). There was only a genotype x treatment interaction for the ball throwing from 7 m (p = 0.037) indicating that the ergogenic effect of caffeine on this test was higher in CYP1A2 AA homozygotes than in C-allele carriers. In the remaining variables, there were no genotype x treatment interactions for CYP1A2 or for ADORA2A. As a whole group, caffeine increased CMJ height, performance in the sprint velocity test, and ball throwing velocity from 9 m (2.8–4.3%, p = 0.001–0.022, effect size = 0.17–0.31). Thus, pre-exercise caffeine supplementation at a dose of 3 mg·kg⁻¹·bm can be considered as an ergogenic strategy to enhance some neuromuscular aspects of handball performance in professional handball players with low daily caffeine consumption. However, the ergogenic response to acute caffeine intake was not modulated by CYP1A2 or ADORA2A genotypes.

Sports supplements are commonly used by elite athletes with the main goal of enhancing sport performance. Supplements use might be substantially different depending on the sport discipline, sex, and competitive level. To date, data about prevalence and the most-commonly used supplements in handball are scarce. Thus, the aim of this investigation was to determine the patterns of supplements use by handball players of both sexes and with different competitive levels: One hundred and eighty-seven handball players (112 men and 75 women) of different competitive levels (106 professional and 81 amateur) completed a validated self-administered questionnaire about supplements use. Supplements were classified according to the categorization of the Australian Institute of Sport (AIS). Overall, 59.9% of the handball players (n = 112) declared the use of at least one supplement and there were no significant differences between men and women (58.9% vs. 61.3%, p = 0.762) nor between professional vs. amateur handball players (67.1% vs. 53.8%, p = 0.074). The most prevalent supplements were sports drinks (42.2%), followed by energy bars (35.3%) and caffeine-containing products (31.6%). However, a greater consumption of group A supplements (those with strong scientific evidence; p = 0.029) and group B supplements (those with emerging scientific support, p = 0.012) was observed in male compared to female handball players. Supplements categorized as medical supplements were more commonly consumed in professional vs. amateur players (0.48 ± 0.80 vs. 0.21 ± 0.44, supplements p < 0.006). Additionally, a higher consumption of group B supplements was observed in professional compared to amateur players (0.58 ± 0.88 vs. 0.33 ± 0.72 supplements, p = 0.015). Handball players revealed a moderate use of supplements while sex and competitive level slighted changed the pattern of supplements use. A high portion of handball players use supplements as fuel during exercise and reported the use of caffeine-containing supplements to enhance performance.

Shoulder pain has been associated with glenohumeral internal rotation deficit (GIRD) and a reduction in external rotation (ER) strength; however, in tennis players, there is scarce evidence regarding the impact of a single match on shoulder range of motion (ROM), strength and serve speed. The aim of this study was to determine the acute effect of a single tennis match on shoulder rotation ROM, isometric strength and serve speed. Twenty-six professional tennis players participated in the study (20.4±4.4 years; 10.5±3.2 years tennis expertise; 20.5±5.4 h/week training). Passive shoulder external (ER-ROM) and internal rotation ROM (IR-ROM), ER and IR isometric strength were measured before and after a single tennis match (80.3±21.3 min) in both shoulder´s. Moreover, the total arc of motion (TAM) and ER/IR strength ratio were calculated. Video analysis was used to assess the number of serves and groundstrokes, while a radar gun was utilized to measure maximal ball speed. In the dominant shoulder, compared to pre-match levels, IR-ROM was significantly reduced (-1.3%; p = 0.042), while ER-ROM (5.3%; p = 0.037) and TAM (3.1%; p = 0.050) were significantly increased. In the non-dominant shoulder, ER-ROM (3.7%; p = 0.006) was increased. Furthermore, in the dominant shoulder, the isometric ER strength was significantly reduced after the match (-4.8%; p = 0.012), whereas serve speed was not significantly reduced after match (-1.16%; p = 0.197). A single tennis match leads to significant reductions in shoulder ROM (e.g., IR of the dominant shoulder) and isometric strength (e.g., ER of the dominant shoulder). This study reveals the importance of recovery strategies prescription aiming at minimize post-match alteration in the shoulders.