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The nurturing of young players in youth academies is seen as an important step on the way to becoming a full professional in the sport of soccer. This longitudinal multi-study investigation, spanning 2009 to 2021, analysed the career paths of Spanish academy soccer players. It consisted of three studies investigating players' transition from academy to professional status and the identification of technical skills and psychological traits which could distinguish future professionals from amateurs. The sample involved 198 male academy soccer players (aged 13.5–17.9) from two Madrid-based professional clubs. Study 1 assessed the outcomes of these players a decade after their academy-level evaluations. Studies 2 and 3 focused on the subgroup of 85 players whose playing status could be verified a decade later. Results showed that 12 players (6.1%) progressed to full-time professional soccer. Of these 12, just 7 reached Spain's highest professional league within 10 years of their final academy tests. Significant differences favouring professional players were observed in the trait of 'self-confidence', 'ball reception', 'dribbling forward with the ball' and coaches' global technical assessments. In conclusion, the chances of academy soccer players achieving professional status are low. Accordingly, providing more developmental opportunities before deselection is crucial to maximise player potential. Coaches could prioritise players' self-confidence and ball control to increase the conversion rate of academy players to professional status. Furthermore, recruitment of players who are already strong in these attributes could also improve the productivity of talent development pipelines. [ABSTRACT FROM AUTHOR]

The effects of an eight-week off-season strength training program upon lower-body strength, power, eccentric capacity, front foot contact (FFC) kinetics, and ball release speed (BRS) in pace bowlers were investigated. Ten elite-academy pace bowlers completed the intervention, and pre- and post-testing. Pre- and post-testing included: double (DLDL) and single leg (SLDL) drop landings; isometric mid-thigh pull (IMTP); countermovement jump; and pace bowling performance (two-over bowling spell measuring BRS and FFC kinetics). Changes from pre- to post-testing were assessed with paired sample t tests (p≤ 0.01), effects sizes and statistical parametrical mapping. Post-testing revealed a significant decrease in peak normalised vertical force during DLDL and SLDL with large effects and a significant, moderate effect increase in IMTP. There was no significant changes in BRS. Concomitantly, neither discrete scalar (p= 0.15-0.58) nor vector field analysis kinetics during FFC indicated significant changes. No significant alterations in FFC kinetics may explain the lack of improvement in BRS (pre = 31.55 ± 1.44 m/s; post = 31.79 ± 1.33 m/s). This study indicated an eight-week strength training program can improve strength and eccentric capacity in pace bowlers, and these changes when developed in the absence of skills training neither improved nor decreased pace bowling performance. [ABSTRACT FROM AUTHOR]

This study compared the acute hypoalgesic and neurophysiological responses to low‐load resistance exercise with and without blood flow restriction (BFR), and free‐flow, high‐load exercise. Participants performed four experimental conditions where they completed baseline measures of pain pressure threshold (PPT), maximum voluntary force (MVF) with peripheral nerve stimulation to determine central and peripheral fatigue. Corticospinal excitability (CSE), corticospinal inhibition and short interval intracortical inhibition (SICI) were estimated with transcranial magnetic stimulation. Participants then performed low‐load leg press exercise at 30% of one‐repetition maximum (LL); low‐load leg press with BFR at 40% (BFR40) or 80% (BFR80) of limb occlusion pressure; or high‐load leg press of four sets of 10 repetitions at 70% one‐repetition maximum (HL). Measurements were repeated at 5, 45 min and 24 h post‐exercise. There were no differences in CSE or SICI between conditions (all P > 0.05); however, corticospinal inhibition was reduced to a greater extent (11%–14%) in all low‐load conditions compared to HL (P < 0.005). PPTs were 12%–16% greater at 5 min post‐exercise in BFR40, BFR80 and HL compared to LL (P ≤ 0.016). Neuromuscular fatigue displayed no clear difference in the magnitude or time course between conditions (all P > 0.05). In summary, low‐load BFR resistance exercise does not induce different acute neurophysiological responses to low‐load, free‐flow exercise but it does promote a greater degree of hypoalgesia and reduces corticospinal inhibition more than high‐load exercise, making it a useful rehabilitation tool. The changes in neurophysiology following exercise were not related to changes in PPT. What is the central question of this study?Does low‐load, blood flow restricted, resistance exercise promote greater hypoalgesic and neurophysiological changes in the 24 h period post‐exercise, in comparison to high‐load resistance exercise?What is the main finding and its importance?Blood flow restriction exercise augments hypoalgesia compared to free‐flow, low‐load exercise and induces similar hypoalgesia to high‐load exercise, but does not result in any different alterations to corticospinal excitability or inhibition. However, corticospinal inhibition was reduced to a greater extent with low‐load exercise, compared to high‐load exercise. Therefore, low‐load BFR resistance exercise is a suitable method for exercise rehabilitation. [ABSTRACT FROM AUTHOR]

Purpose: To examine the effect of fast- versus slow-speed eccentric-muscle-action resistance training on lower-body strength, vertical jump height, sprint speed, and change-of-direction performance in elite soccer players during a competitive season. Methods: Twenty-two elite soccer players, from a single team, were randomly assigned to groups that undertook either 1- (fast speed) or 4-second (slow speed) eccentric resistance training during the in-season period. A 5-week program was conducted during an elite top-division European League soccer season. Performance measures including predicted 1-repetition-maximum back squat, countermovement jump, 20-m sprint, and change of direction were tested before and after the intervention period. Total match and training running distance and muscle soreness were also recorded during each week of the intervention. Results: An analysis of covariance showed significant group effects (P =.01) for countermovement jump with a greater jump height in the 1-second fast-speed group postintervention (95% CI, 1.1–6.9 cm). Despite an overall increase in 1-repetition maximum pretraining to posttraining (95% CI, 10.0–15.3 kg, effect size 0.69), there were no significant differences (P >.05) between groups after the intervention. Similarly, there were no differences between groups for change of direction, 20-m sprint, or muscle soreness. Conclusion: Faster eccentric muscle actions may be superior for increasing movements in elite soccer players in-season. [ABSTRACT FROM AUTHOR]

Cold-water immersion (CWI) has been reported to reduce tissue metabolism postimmersion, but physiological data are lacking regarding the muscle metabolic response to its application. Near-infrared spectroscopy (NIRS) is a noninvasive optical technique that can inform muscle hemodynamics and tissue metabolism. To investigate the effects of CWI at 2 water temperatures (10°C and 15°C) on NIRS-calculated measurements of muscle oxygen consumption (mVO2). Crossover study. University sports rehabilitation center. A total of 11 male National Collegiate Athletic Association Division II long-distance runners (age = 23.4 ± 3.4 years, height = 1.8 ± 0.1 m, mass = 68.8 ± 10.7 kg, mean adipose tissue thickness = 6.7 ± 2.7 mm). Cold-water immersion at 10°C and 15°C for 20 minutes. We calculated mVO2 preimmersion and postimmersion at water temperatures of 10°C and 15°C. Changes in tissue oxyhemoglobin (O2Hb), deoxyhemoglobin (HHb), total hemoglobin (tHb), hemoglobin difference (Hbdiff), and tissue saturation index (TSI %) were measured during the 20-minute immersion at both temperatures. We observed a decrease in mVO2 after immersion at both 10°C and 15°C (F1,9 = 27.7801, P =.001). During the 20-minute immersion at both temperatures, we noted a main effect of time for O2Hb (F3,27 = 14.227, P =.001), HHb (F3,27 = 5.749, P =.009), tHb (F3,27 = 24.786, P =.001), and Hbdiff (F3,27 = 3.894, P =.020), in which values decreased over the course of immersion. Post hoc pairwise comparisons showed that these changes occurred within the final 5 minutes of immersion for tHb and O2Hb. A 20-minute CWI at 10°C and 15°C led to a reduction in mVO2. This was greater after immersion at 10°C. The reduction in mVO2 suggests a decrease in muscle metabolic activity (ie, O2 use after CWI). Calculating mVO2 via the NIRS-occlusion technique may offer further insight into muscle metabolic responses beyond what is attainable from observing the NIRS primary signals. [ABSTRACT FROM AUTHOR]

This study investigated whether anthropometric and physical abilities explained variance in match collision performance among international female rugby union players. Physical performance and anthropometric data for fifty-one international female rugby union players, and collision actions categorised as "effort" or "performance" variables, from 20 international matches, were analysed using partial least squares regression. Among forwards, variance in carries/min was explained (R2 =.22) by a combination of; body mass, skinfolds, acceleration momentum and negative associations with mean aerobic speed and single-leg isometric squat relative force (SLISO/kgBM). Variance in collision dominance among forwards was explained (R2 =.21) by lower skinfolds and higher acceleration momentum, while tackles/min (R2 =.19) were explained by greater jumping power and single-leg isometric squat (SLISO). Among backs, variance in tackles/min (R2 =.54) was explained by greater bench press, SLISO and SLISO/kgBM. Variance in collision dominance among backs was explained (R2 =.23) by negative and positive associations with body mass and SLISO/kgBM, respectively. These findings suggest the development of physical characteristics, such as body mass and composition, strength and power contribute towards successful collision actions among international female rugby union players. The contribution of different physical characteristics towards collision events is dependent on position, and whether the collision event is categorised by "performance" or "effort". It is suggested that physical training programmes should reflect this level of specificity. Highlights Among elite female rugby union forwards, acceleration momentum, body mass and skinfolds are positively associated with winning collisions and carrying the ball into contact more frequently, whilst tackle frequency is positively associated with relative leg strength and power output. Among elite female backs, the ability to win collisions is positively associated with relative leg power output, and negatively associated with body mass. Tackle frequency is associated with maximum upper- and lower-body strength in this group. Physical characteristics account for some of the variability in collision performance, but interpretation of these findings should consider that factors such as technique during collision events may account for a larger proportion of total variance. Sports science practitioners can improve collision performance, to varying degrees, by enhancing specific gross physical characteristics, according to a player's position and the tactical role they are expected to fulfil. [ABSTRACT FROM AUTHOR]