Screening Youth Soccer Players by Means of Cognitive Function and Agility Testing.

Talent identification in sports is a heavily debated topic. Previous studies have separately explored either executive functions or gross motor skills to predict the success of top-level soccer players or, more generally, to characterize elite performance in soccer. However, at mid-childhood, the possibility to scope sport-specific requirements remains elusive. We aimed in this study to investigate a valid and simple method of testing for a unique combination of cognitive and speed abilities for identifying promising soccer players at mid-childhood. We measured cognitive functions by means of a Stroop smartphone application and agility with a T-Drill Ball-success test, in two groups of (a) elite- (n = 31) and (b) low-division (n = 37) Italian 7-year-old male soccer players. We administered the tests in a randomized order to both groups. We found better inhibitory control, cognitive flexibility and soccer-specific agility in high-division versus low-division players (p < .001). Inhibitory response and agility were positively associated with the augmented quality of the performance from low-division players to high-division players (r = .55; p = .0001). These results suggest that, even at an early age, cognitive control together with soccer-specific skills is associated with better performance.

Influence of ball possession and playing position on the physical demands encountered during professional basketball games.

Understanding the game demands encountered in basketball provides useful insight for developing specific, individualized and team-based training sessions. This study quantified and compared the game activity demands encountered by basketball players of different playing positions: i) strictly when in possession of the ball and ii) overall during live playing time (irrespective of ball possession). The activity demands encountered by 44 (22 guards, 14 forwards, 8 centres) adult, professional, male basketball players were assessed across 10 official games. Time-motion analysis was used to determine the frequency and proportion (%) of playing time performing recovery (REC), low- (LIA), moderate- (MIA), and high- (HIA) intensity activities. Linear mixed models were constructed to examine differences in dependent variables between playing positions, accounting for repeated measures. Guards, forwards, and centres spent 11.9±5.9%, 3.5±1.3%, and 2.9±1.1% of live playing time in possession of the ball, respectively. Guards performed more activities at all intensities (total movements, REC, LIA, MIA, and HIA) than forwards (P < 0.05) and centres (P < 0.05) when in possession of the ball. The proportion of time spent performing HIA in possession of the ball was greater for forwards (P = 0.001) and centres (P = 0.001) than guards. During live playing time overall across games, centres performed more HIA per minute (P = 0.049) and spent a greater proportion of time performing HIA (P = 0.047) than guards. Activities performed when in possession of the ball and during live playing time across basketball games are affected by playing position. These data highlight the need to develop position-specific training drills, particularly with ball possession.

Effects of Two High-intensity Interval Training Concepts in Recreational Runners.

This study investigated the effects induced by 8 weeks of two high-intensity interval training (HIIT) protocols, 10-20-30 and 30-30 concepts, characterized by significantly different training volume and intensity, on physiological parameters, running performance, body composition and psychophysiological stress of recreational divided into two groups: the 10-20-30 group performed two 10-20-30 sessions/wk and one continuous training (CT)/wk, whilst the 30-30 group performed two 30-30 sessions/wk and one CT session/wk. VO2max, 1 km time, maximal aerobic speed (MAS), and body composition were evaluated before and after intervention. Internal load was measured through rating of perceived exertion (RPE). Both groups significantly improved running performance (1 km time: p=0.04; MAS: p=0.000001), aerobic fitness (VO2max: p=0.000002) and body composition (lean mass (kg) p=0.0001; fat mass (%) p=0.00005). RPE resulted significantly lower in the 10-20-30 group than in 30-30 group (10-20-30: 13.36±0.28; 30-30:15.55±0.21; p=0.0002). Thus, the 10-20-30 group improved physiological parameters, performance and body composition, similar to 30-30 with significantly lower RPE values. These results suggest that in recreational runners the 10-20-30 training is effective in improving aerobic fitness and performance, with a lower subjective perception of effort, thus enhancing individual compliance and adherence to the prescribed training program.

Correction: Six minute walk distance and reference values in healthy Italian children: A cross-sectional study.

[This corrects the article DOI: 10.1371/journal.pone.0205792.].

Rates of insufficiency and deficiency of vitamin D levels in elite professional male and female skiers: A chronobiologic approach.

Vitamin D is essential for the maintenance and promotion of musculoskeletal health, for the functioning of the immune, cardiovascular and reproductive systems, and its main action is to keep calcium and phosphate plasmatic physiological concentrations at intestinal, renal and bony level. Vitamin D affects several parameters related to physical performance too and a particularly high percentage of vitamin D insufficiency and deficiency in professional athletes has been observed. Several variables are able to impair the synthesis of 25(OH)D in athletes, specifically both genetic and environmental factors, but the most probable explanation for the deficient/insufficient vitamin D levels is the insufficient ultraviolet B light (UVB) exposure during winter. To confirm this, the existence of a circannual rhythm of vitamin D in professional soccer players, highlighting a peak in summer and lowest values in winter regardless the period of the season, has been documented. Nonetheless, from what we are aware of, no other study adopted a chronobiologic approach to better understand and describe the circannual variations of serum 25(OH)D in other sport disciplines. Therefore, we studied serum vitamin D in a cohort of top-level professional skiers, during a period of three consecutive competitive seasons (2015, 2016 and 2017), in order to evaluate, with a rhythmometric approach, the vitamin D behavior along the year. The study population was composed by 152 professional Italian alpine skiers of FISI (Winter Sport Italian Federation), 63 females and 89 males (mean age: 24.1 ± 3.2 years) and a total of 298 blood drawings were carried out to determine plasma 25(OH)D. Vitamin D data were compared between genders and then processed with the population mean cosinor tests to evaluate the presence of a circannual rhythm, both for female and male athletes. In total, 77 skiers (50.7%) showed, at least once during the three competitive seasons, an insufficient level of 25(OH)D and other 45 subjects (29.6%) showed a deficient status; no differences were observed between genders (mean for females: 26.9 ± 8.1 ng/mL; mean for males: 27.4 ± 7.6 ng/mL). In addition, the rhythmometric analysis highlighted the existence of a significant circannual rhythm for both female and male professional skiers; the acrophases (Φ) occurred in July and both MESOR (M) and amplitude (A) were comparable between the two groups. Our data indicate that, despite the physical effort spent, vitamin D follows a classical season-associated rhythm with a peak in summer and a nadir in winter. Moreover, the percentage of insufficiency and deficiency is in line with that of the general population. In conclusion, our findings reinforce the hypothesis that there is no direct effect of physical activity on vitamin D metabolism and that the factors involved in the determination of vitamin D levels in the general population are valid also for athletes.

Elite Female Basketball Players' Body-Weight Neuromuscular Training and Performance on the Y-Balance Test.

CONTEXT: Neuromuscular training enhances unconscious motor responses by stimulating both the afferent signals and central mechanisms responsible for dynamic joint control. Dynamic joint-control training is a vital component of injury-prevention programs. OBJECTIVE: To investigate the effects of body-weight neuromuscular training on Y-Balance Test (YBT) performance and postural control in female basketball players. DESIGN: Randomized controlled clinical trial. SETTING: Basketball practice sessions. PATIENTS OR OTHER PARTICIPANTS: A total of 28 healthy elite female basketball players were randomly assigned to an experimental (n = 14) or a control group (n = 14). INTERVENTION(S): Before their regular practice sessions, the experimental group warmed up with body-weight neuromuscular exercises and the control group with standard tactical-technical exercises twice weekly for 8 weeks. MAIN OUTCOME MEASURE(S): Anterior-, posteromedial-, and posterolateral-reach and composite YBT scores were measured before and after 8 weeks of training. RESULTS: Improvement over baseline scores was noted in the posteromedial (right = 86.5 ± 4.5 cm versus 89.6 ± 2.2 cm, +3.5%, P = .049; left = 85.5 ± 4.3 cm versus 90.2 ± 2.7 cm, +5.5%, P = .038)- and posterolateral (right = 90.7 ± 3.6 cm versus 94.0 ± 2.7 cm, +3.6%, P = .016; left = 90.9 ± 3.5 cm versus 94.2 ± 2.6 cm, +3.6%, P = .011)-reach directions and in the composite YBT scores (right = 88.6% ± 3.2% versus 94.0% ± 1.8%, +5.4%, P = .0004; left = 89.2% ± 3.2% versus 94.5% ± 3.0%, +5.8%, P = .001) of the experimental group. No differences in anterior reach were detected in either group. Differences were noted in postintervention scores for posteromedial reach (right = 89.6 ± 2.2 cm versus 84.3 ± 4.4 cm, +4.1%, P = .005; left = 94.2 ± 2.6 cm versus 84.8 ± 4.4 cm, +10%, P = .003) and composite scores (right = 94.0% ± 1.8% versus 87.3% ± 2.0%, +7.1%, P = .003; left = 94.8% ± 3.0% versus 87.9% ± 3.4%, +7.3%, P < .0001) between the experimental and control groups. CONCLUSIONS: Body-weight neuromuscular training improved postural control and lower limb stability in female basketball players as assessed with the YBT. Incorporating neuromuscular training into the workout routines for basketball players may enhance joint awareness and reduce the risk of lower extremity injury.