Table 3.
Sub analysis of the effect of POL compared to other TIDs according to intervention duration and to athlete level
| Intervention groups | VO2max/peak | Time trial | Time to exhaustion | V/P at VT2/LT2 | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| N | SMD (95% CI) | I2 | Z (p) | N | SMD (95% CI) | I2 | Z (p) | N | SMD (95% CI) | I2 | Z (p) | N | SMD (95% CI) | I2 | Z (p) | |
| POL vs. ALL (< 12 weeks) | 163 | 0.40 (0.08; 0.71) | 0% | 2.49 (0.01)* | 146 | 0.00 (– 0.32; 0.33) | 0% | 0.03 (0.98) | – | – | – | – | 164 | 0.07 (– 0.24; 0.38) | 0% | 0.46 (0.65) |
| POL vs. ALL (≥ 12 weeks) | 121 | 0.04 (– 0.32; 0.40) | 0% | 0.22 (0.83) | 87 | – 0.14 (– 0.56; 0.29) | 0% | – 0.63 (0.53) | 44 | 0.09 (– 0.51; 0.68) | 0% | 0.28 (0.78) | 89 | – 0.02 (– 0.44; 0.40) | 0% | – 0.09 (0.93) |
| POL vs. ALL (Highly Trained) | 118 | 0.46 (0.10; 0.82) | 0% | 2.51 (0.01)* | 54 | – 0.04 (– 0.58; 0.50) | 0% | – 0.14 (0.89) | – | – | – | – | 74 | – 0.06 (– 0.52; 0.40) | 0% | – 0.27 (0.79) |
| POL vs. ALL (Trained) | 159 | 0.08 (– 0.23; 0.39) | 0% | 0.50 (0.62) | 167 | – 0.00 (– 0.31; 0.30) | 0% | – 0.03 (0.98) | 66 | 0.30 (– 0.20; 0.79) | 0% | 1.18 (0.24) | 179 | 0.08 (– 0.21; 0.38) | 0% | 0.55 (0.58) |
| POL vs. ALL (TT < 12 min) | 129 | – | – | – | 116 | – 0.00 (– 0.37; 0.37) | 0% | – 0.01 (1.00) | – | – | – | – | – | – | – | – |
| POL vs. ALL (TT ≥ 12 min) | 159 | – | – | – | 105 | – 0.03 (– 0.41; 0.36) | 0% | – 0.13 (0.89) | – | – | – | – | – | – | – | – |
ALL other training intensity distribution, POL polarized training, TT time trial, TTE time to exhaustion, V/P at VT2/LT2 velocity or power at second ventilatory or lactate threshold, VO2max/peak maximal/peak oxygen uptake, SMD standardized mean difference, I2 (p) heterogeneity and p-value, Z (p) test for overall effect and p-value
*Statistical significance: p < 0.05