Effects of four different times of day on various aspects of maximal short-term physical performance in young soccer players.
Level 2 - randomized trial
Randomized crossover trial testing four time-of-day conditions
PubMed 41142303 · doi:10.7717/peerj.20065
What was done
Nineteen male adolescent soccer players (mean age: 14.58 ± 0.7 years) participated in a randomized trial evaluating performance across four times of day (08:00, 11:00, 15:00, and 18:00 h), separated by at least 48 hours of recovery between sessions. Measured outcomes included oral temperature (OT), medicine ball throw (MBT), 5-meter sprint (5m-T), 20-meter sprint (20m-T), Illinois Agility Test (IAT), and Illinois Agility Test with Ball (IAT-B).
What was found
Oral temperature increased significantly from 08:00 to 18:00 (p < 0.001). Physical performance metrics (MBT, 5m-T, 20m-T, IAT, and IAT-B) improved significantly at 11:00, 15:00, and 18:00 relative to 08:00 (all p < 0.05), with 18:00 consistently yielding the highest performance levels. Performance did not differ significantly between 11:00 and 15:00 (all p > 0.05). Specific numerical values, standard deviations, and effect sizes for the performance tests were not reported in the abstract.
Why it matters
This study indicates that diurnal variations in physical capacity observed in adults also affect adolescent athletes, suggesting that high-intensity training and performance monitoring should account for time-of-day effects.
Limits
The sample size is small (n = 19) and limited exclusively to adolescent males. The abstract does not report baseline chronotype, sleep patterns, dietary standardization, or precise numerical values and effect sizes for the performance outcomes. Aerobic capacity and match performance were not tested.
Cited by
- supports Mental and physical performance peaks approximately 3 hours and 11 hours after waking, driven by diurnal variations in body temperature and circulation.