Table 1. Baseline characteristics of adolescent soccer players participating in the study (n = 19).
Values are presented as mean ± standard deviation (SD), along with minimum and maximum values where applicable. Variables include age, body mass, height, body mass index (BMI), Morningness–Eveningness Questionnaire (MEQ) score, Pittsburgh Sleep Quality Index (PSQI) score, average sleep duration, years of sports experience, frequency of weekly training sessions, usual time of day (TOD) for training, and average duration of training sessions. MEQ scores range from 16 to 86; PSQI scores range from 0 to 21.
| Minimum | Maximum | Mean | |
|---|---|---|---|
| Age (years) | 13 | 15 | 14.58 ± 0.77 |
| Body mass (kg) | 40.7 | 80.2 | 57 ± 12.8 |
| Height (m) | 1.58 | 1.83 | 1.71 ± 0.09 |
| BMI (kg/m 2 ) | 16.1 | 25.6 | 19.2 ± 2.7 |
|
MEQ score (au)
(ranging from 16–86) |
43 | 56 | 50.47 ± 4.09 |
|
PSQI score (au)
(ranging from 0 to 21) |
1 | 6 | 2.89 ± 1.45 |
| Sleep duration (h) | 7 | 10 | 8.21 ± 0.98 |
| Experience (years) | 2 | 6 | 3 ± 1.41 |
| Training sessions frequency/week | 2 | 5 | 3.11 ± 0.74 |
| Usual Training TOD (h) | 17:00 | 17:00 | 17:00±0 |
| Usual training session duration (min) | 75 | 75 | 75±0 |
Notes.
MEQ, morningness-eveningness questionnaire of Horne & Ostberg (1976); TOD, Time of day. The minimum, maximum, mean, and standard deviation values of the participants’ characteristics are shown in the table.