Table 1.
Average metabolic rate and step parameters during treadmill running in Vaporfly shoes with VFintact and VFcut carbon-fiber plates (mean ± SD).
| Variable | VFintact | VFcut | Within-subject change (%) | p |
|---|---|---|---|---|
| Metabolic power (W/kg) | 14.09 ± 0.80 | 14.17 ± 0.74 | 0.55 ± 1.77 | 0.306 |
| Peak vertical GRF (BW) | 2.64 ± 0.20 | 2.64 ± 0.19 | 0.22 ± 0.77 | 0.371 |
| Braking impulse (BW·s) | –0.02 ± 0.00 | –0.02 ± 0.00 | –0.20 ± 1.65 | 0.607 |
| Propulsive impulse (BW·s) | 0.02 ± 0.00 | 0.02 ± 0.00 | –0.22 ± 1.65 | 0.589 |
| Contact time (s) | 0.213 ± 0.014* | 0.211 ± 0.014* | –1.19 ± 1.10* | <0.001 |
| Step frequency (steps/s) | 3.00 ± 0.12 | 3.00 ± 0.12 | 0.02 ± 0.82 | 0.909 |
Note: Average within-subject changes are reported as a percentage difference (VFcut – VFintact)/VFintact × 100%.
Abbreviations: BW = body weight; VFcut = cut Nike Vaporfly 4%; VFintact = intact Nike Vaporfly 4%; W = watt.
⁎
p < 0.001, statistical difference between shoe conditions.