Table 1. Pre-exercise muscle function and performance data during the 40% and 80% protocols.
All participants completed the VOL–1 workload without stopping. 3 out of 10 participants completed the second 30s contraction at 80% without stopping (VOL–1 to VOL–2). 6 out of 10 participants completed the second 60s contraction at 40% (VOL–1 to VOL–2) without stopping.
| 40% Protocol | 80% Protocol | |
|---|---|---|
| MVT (Nm) | 280.1 ± 48.3 | 258.9 ± 53.0 |
| VA (%) | 90.1 ± 7.7 | 90.8 ± 9.9 |
| VL M-wave (mV) | 12.3 ± 5.3 | 12.1 ± 5.6 |
| VM M-wave (mV) | 18.2 ± 2.0 | 18.6 ± 4.2 |
| VL EMG/M (%) | 14.0 ± 5.1 | 10.0 ± 3.4 |
| VM EMG/M (%) | 12.6 ± 5.0 | 10.3 ± 3.3 |
| VL V/M (%) | 21.1 ± 14.4 | 22.9 ± 8.7 |
| VM V/M (%) | 28.7 ± 17.3 | 21.6 ± 15.1 |
| Q.pot.tw.max | 62.8 ± 6.6 | 59.7 ± 10.6 |
| Time to reach VOL–2 (s) | 211.4 ± 38.9 | 207 ± 56.8 |
| Time to exhaustion, final contraction (s) | 46.1 ± 10.1*** | 10.8 ± 3.5 |
***is p<0.001 between protocols.
MVT, maximal voluntary torque; VA, voluntary activation; VL, vastus lateralis; VM, vastus medialis; M-wave, muscle compound action potential; EMG, electromyogram; V/M, V-wave amplitude normalized to M-wave; Q.pot.tw.max, quadriceps potentiated twitch maximum. Data are mean ± SD.