Table 1.
Biological maturation characteristics and anthropometric pre-post changes of the subjects.
| Variable | Test | HIIT-EM (n = 12) | Effect size | HIIT-NM (n = 17) | Effect size | P-value HIIT-EM vs. HIIT-NM baseline | P-value HIIT-EM vs. HIIT-NM pre-post |
|---|---|---|---|---|---|---|---|
| Gender (♀ / ♂) | 7 / 4 | 9 / 8 | |||||
| Age (y) | Pre | 11.0 ± 1.0 | 12.0 ± 1.0 | 0.067 | |||
| Genital maturation | Pre | 1.9 ± 1.0 | 2.9 ± 0.9 | <0.01 | |||
| Pubic hair maturation | Pre | 3.0 ± 1.0 | 3.0 ± 1.0 | 0.229 | |||
| Height (cm) | Pre | 145.0 ± 0.11 | 153.0 ± 0.06 | <0.01 | <0.01 | ||
| Post | 146.3 ± 0.06 | 154.6 ± 0.09 | |||||
| ANTHROPOMETRIC | |||||||
| Body mass index (kg/m2) | Pre | 26.2 ± 5.6 | 0.02 (−0.07, 0.10) | 27.1 ± 4.7 | −0.08 (−0.14, −0.02) | 0.633 | 0.023 |
| Post | 26.3 ± 5.4 | 26.7 ± 4.2 | |||||
| P-value | 0.322 | 0.065 | |||||
| Δ% | 0.3 | −1.4 | |||||
| Waist circumference (cm) | Pre | 86.8 ± 14.0 | −0.01 (−0.31, 0.04) | 88.0 ± 9.8 | −0.22 (−0.35, −0.10)$ | 0.801 | 0.345 |
| Post | 84.6 ± 13.2 | 85.7 ± 9.1 | |||||
| P-value | 0.144 | 0.139 | |||||
| Δ% | −2.5 | −2.6 | |||||
| Supra-iliac skinfold (mm) | Pre | 42.5 ± 10.8 | −0.44 (−0.60, −0.29)$ | 41.1 ± 6.7 | −1.24 (−1.55, −0.92)‡ | 0.661 | 0.056 |
| Post | 35.7 ± 9.0 | 33.3 ± 5.8 | |||||
| P-value | <0.01 | <0.01 | |||||
| Δ% | −16.0 | −18.9 | |||||
Data presented as mean and ± SD. Delta changes (Δ%) is presented in percentage. Groups are described as HIIT-EM, high intensity interval training earlier matures; HIIT-NM, high intensity interval training normal matures. Variables are described as ♀ = girls; ♂ = boys. Bold values indicate significant differences at level P ≤ 0.05.
$
Small standardized effect at level P ≤ 0.05.
‡
Large standardized effect at level P ≤ 0.05.