Table 1.
Heart rate, exercise performance, core body temperature, skin temperature, heat gradient, subjective parameters and body weight in both environmental conditions (mean ± SD; median (25–75 percentiles)).
| Outcome parameters | Cool | Hot | P-value | Effect Size [95% CI] |
|---|---|---|---|---|
| Heart Rate (bpm) | ||||
| Heart rate | 162 ± 3 | 164 ± 4 | 0.055 | 0.90 [–0.20, 2.00] |
| Performance (km) | ||||
| Covered distance | 24.9 ± 14.2 | 23.1 ± 12.9 | 0.013 | 1.32 [0.16, 2.48] |
| Core Body Temperature (°C)* | ||||
| Change during warming up | 0.5 ± 0.3 | 0.4 ± 0.1 | 0.61 | 0.22 [–0.91, 1.36] |
| Peak class-specific test | 38.5 ± 0.1 | 39.2 ± 0.2 | 0.001 | 3.13 [1.44, 4.82] |
| Change during class-specific test | 1.0 ± 0.2 | 1.6 ± 0.3 | 0.002 | 2.50 [0.99, 4.01] |
| Change during recovery | −0.6 ± 0.2 | −0.2 ± 0.3 | 0.014 | 1.52 [0.24, 2.81] |
| Skin Temperature (°C)* | ||||
| Change during warming up | 0.5 ± 0.8 | 0.8 ± 0.6 | 0.69 | 0.17 [–0.96, 1.31] |
| Peak class-specific test | 31.2 ± 1.2 | 36.7 ± 0.3 | <0.001 | 6.28 [3.53, 9.04] |
| Change during class-specific test | 0.5 ± 1.0 | 0.9 ± 0.3 | 0.36 | 0.41 [–0.73, 1.55] |
| Change during recovery | 0.7 ± 1.2 | −0.4 ± 0.3 | 0.11 | 0.78 [–0.39, 1.95] |
| Heat Gradient (°C)* | ||||
| Change during warming up | −0.2 ± 0.7 | −0.3 ± 0.5 | 0.85 | 0.09 [–1.15, 1.33] |
| Change during class-specific test | 0.5 ± 1.0 | 0.5 ± 0.3 | 0.89 | 0.07 [–1.17, 1.31] |
| Change during recovery | −1.1 ± 1.4 | 0.2 ± 0.5 | 0.13 | 0.86 [–0.43, 2.16] |
| Subjective Parameters (au) | ||||
| Rate of perceived exertion | 14.2 ± 0.6 | 13.9 ± 1.2 | 0.59 | 0.21 [–0.84, 1.26] |
| Thermal comfort | 2.7 ± 0.3 | 1.8 ± 0.4 | 0.001 | 2.26 [0.92, 3.61] |
| Thermal sensation | 1.7 (0.2–1.8) | 2.7 (2.7–2.9) | 0.018** | – |
| Body Weight (%) | ||||
| ∆ Body weight | −0.7 ± 0.4 | −1.1 ± 0.2 | <0.001 | 2.85 [1.36, 4.34] |
bpm = beats per minute, AU: arbitrary units. P-values refer to Paired-Sample T-Tests, while effect sizes (ES) are indicate by Cohen’s d (negligible effect = 0–0.19, small effect = 0.20–0.49, moderate effect = 0.50–0.79, large effect ≥0.80).
*TC of 470 Helm – Women and TSK of Finn – Men are not included due to complications while measuring. Thereby, heat gradient of both athletes are also not included.
**P-value refers to a Wilcoxon Signed-Rank Test, while effect size is not indicated.