Table 1.
Characteristics of the participants
| All athletes
(n=48) |
Indoor athletes
(n=21) |
Outdoor athletes
(n=27) |
P Value | |
| Age, y | 19.8±0.9 | 20.0±1.0
(19–21) |
19.7±0.8
(19–21) |
NS♰ |
| Height, cm | 171.5±4.8 | 172±4.8
(163–181) |
171±4.8
(163–186) |
NS♰ |
| Body weight, kg | 62.8±7.4 | 64.7±5.9
(57.1–80.2) |
61.3±8.2
(52.6–91.9) |
NS♰ |
| BMI, kg/m2 | 21.3±2.5 | 21.9±2.2
(19.2–29.3) |
20.8±2.6
(17.0–29.7) |
NS♰ |
| Body fat percentage, % | 10.8±3.7 | 12.2±3.2
(6.6–20.2) |
9.7±3.7
(3.0–22.6) |
<0.05♰ |
| Muscle mass, kg | 52.9±4.6 | 53.8±3.7
(48.3–62.3) |
52.2±5.1
(45.9–67.4) |
NS♰ |
| Bone mass, kg | 2.9±0.2 | 2.9±0.2
(2.7–3.4) |
2.9±0.3
(2.5–3.7) |
NS♰ |
| Practice time with sunlight exposure, h/wk | 10.1±8.0 | 1.3±1.5
(0–2.0) |
17.0±2.0
(11.0–21.0) |
<0.001♰ |
| Time of sleeping, h/dy | 6.2±1.0 | 6.4±0.8
(5–8) |
6.1±1.2
(3–9) |
NS♰ |
| Past history of stress fracture | 6/48 | 3/21
(14.3%) |
3/27
(11.1%) |
NS* |
| Past history of other fracture | 21/48 | 7/21
(33.3%) |
14/27
(51.9%) |
NS* |
| No history of fracture | 21/48 | 11/21
(52.4%) |
10/27
(37.0%) |
NS* |
The values are given as means±standard deviation.
♰ Stundent’s t-test.
* Chi-squared test.
NS: not significant