Table 2.
Isokinetic muscle strength and endurance before and after long-duration spaceflight with standard of care exercise or Sprint exercise prescription.
| CON | SPRINT | |||||||
|---|---|---|---|---|---|---|---|---|
| Preflight | R + 5 | R + 14 | R + 30 | Preflight | R + 5 | R + 14 | R + 30 | |
| Knee ext, 60° s−1 | 208 ± 11 | 194 ± 11* | 191 ± 11* | 195 ± 11* | 191 ± 15 | 177 ± 15* | 186 ± 11* | 188 ± 15* |
| Knee flex, 60° s−1 | 113 ± 6 | 102 ± 6*** | 103 ± 6*,** | 107 ± 6*,** | 100 ± 7 | 100 ± 7* | 102 ± 7* | 103 ± 7* |
| Knee ext, 180° s−1 | 2657 ± 121 | 2466 ± 121*** | 2509 ± 121* | 2599 ± 121 | 2500 ± 161 | 2207 ± 161* | 2381 ± 161* | 2406 ± 161 |
| Knee flex, 180° s−1 | 1573 ± 77 | 1403 ± 77* | 1439 ± 77* | 1489 ± 77* | 1518 ± 103* | 1394 ± 103* | 1461 ± 103* | 1515 ± 103* |
| Ankle conc PF, 30° s−1 | 134 ± 6 | 120 ± 6* | 123 ± 6* | 132 ± 6 | 131 ± 8 | 116 ± 8* | 120 ± 8* | 133 ± 8 |
| Ankle ecc PF, 30° s−1 | 191 ± 11 | 172 ± 11* | 180 ± 11 | 189 ± 11 | 193 ± 15 | 161 ± 15* | 174 ± 15 | 198 ± 15 |
| Trunk ext, 60° s−1 | 446 ± 26 | – | 408 ± 27*,** | 423 ± 27 | 400 ± 35 | – | 429 ± 36* | 393 ± 35 |
| Trunk flex, 60° s−1 | 225 ± 10 | – | 196 ± 12* | 210 ± 11 | 196 ± 14 | – | 172 ± 14* | 181 ± 14 |
Data are mean ± SE and represent peak torque for the single highest repetition (Nm) or total work for an entire set of repetitions (J; knee extension and flexion at 180° s−1) during isokinetic dynamometry conducted approximately 50 days preflight (L-50) and 5, 14, and 30 days postflight (R + 5, R + 14, and R + 30). Per protocol trunk strength is not assessed at R + 5 testing, CON control group that performed the ISS standard of care exercise prescription, SPRINT experimental group that performed a high intensity/lower volume exercise prescription, ext extension, flex flexion, conc PF concentric plantarflexion, ecc PF eccentric plantarflexion.
*Simple main effect for time relative to preflight (P < 0.05).
**Simple group × time interaction effect relative to preflight (P < 0.05).