Table 2.
Differences in muscle electrical activity (EMG) in muscular strength and power test among experimental conditions
| MPLA | MCAF | EPLA | ECAF | ANOVA effects (partial η2) | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Mean ± SD | Mean ± SD | Mean ± SD | Mean ± SD | Supplement | Load | Supplement by Day | Supplement by Load | Supplement by Day by Load | |||
| 25% 1RM | Pectoralis major | RMS (μV) | 100 ± 59 | 85 ± 45 | 85 ± 36 | 76 ± 32 | 0.883 (0.004) | 0.001 (0.734) | 0.373 (0.134) | 0.353 (0.162) | 0.501 (0.109) |
| MVC (N) | 547 ± 352 | 452 ± 261 | 497 ± 154 | 481 ± 205 | 0.968 (0.001) | 0.001 (0.743) | 0.290 (0.184) | 0.518 (0.106) | 0.822 (0.026) | ||
| Triceps brachii | RMS (μV) | 97 ± 24 | 86 ± 31 | 89 ± 38 | 103 ± 54 | 0.480 (0.087) | 0.001 (0.613) | 0.210 (0.247) | 0.356 (0.156) | 0.749 (0.050) | |
| MVC (N) | 535 ± 139 | 483 ± 175 | 496 ± 198 | 680 ± 230 | 0.566 (0.058) | 0.005 (0.500) | 0.182 (0.275) | 0.302 (0.180) | 0.412 (0.121) | ||
| Rectus femoris | RMS (μV) | 64 ± 31 | 58 ± 34 | 62 ± 32 | 63 ± 53 | 0.572 (0.037) | 0.020 (0.300) | 0.370 (0.090) | 0.181 (0.163) | 0.550 (0.066) | |
| MVC (N) | 512 ± 284 | 486 ± 226 | 532 ± 198 | 487 ± 276 | 0.912 (0.001) | 0.002 (0.461) | 0.430 (0.071) | 0.948 (0.005) | 0.732 (0.026) | ||
| Vastus lateralis | RMS (μV) | 77 ± 36 | 78 ± 44 | 78 ± 33 | 76 ± 54 | 0.865 (0.003) | 0.046 (0.173) | 0.891 (0.002) | 0.507 (0.081) | 0.402 (0.096) | |
| MVC (N) | 449 ± 153 | 493 ± 179 | 433 ± 79 | 418 ± 186 | 0.301 (0.118) | 0.004 (0.379) | 0.259 (0.139) | 0.807 (0.023) | 0.928 (0.004) | ||
| 50% 1RM | Pectoralis major | RMS (μV) | 120 ± 37 | 102 ± 53 | 125 ± 52 | 112 ± 63 | |||||
| MVC (N) | 650 ± 413 | 557 ± 308 | 578 ± 180 | 596 ± 258 | |||||||
| Triceps brachii | RMS (μV) | 114 ± 44 | 92 ± 25 | 99 ± 33 | 112 ± 61 | ||||||
| MVC (N) | 746 ± 196 | 697 ± 207 | 657 ± 168 | 704 ± 194 | |||||||
| Rectus femoris | RMS (μV) | 76 ± 43 | 62 ± 32 | 77 ± 32 | 80 ± 50 | ||||||
| MVC (N) | 463 ± 269 | 484 ± 228 | 502 ± 261 | 470 ± 187 | |||||||
| Vastus lateralis | RMS (μV) | 82 ± 26 | 86 ± 59 | 85 ± 31 | 79 ± 39 | ||||||
| MVC (N) | 389 ± 178 | 443 ± 276 | 372 ± 77 | 378 ± 179 | |||||||
| 75% 1RM | Pectoralis major | RMS (μV) | 124 ± 102 | 111 ± 50 | 120 ± 58 | 116 ± 67 | |||||
| MVC (N) | 671 ± 314 | 619 ± 328 | 634 ± 246 | 637 ± 222 | |||||||
| Triceps brachii | RMS (μV) | 123 ± 35 | 101 ± 45 | 113 ± 31 | 116 ± 50 | ||||||
| MVC (N) | 636 ± 148 | 640 ± 225 | 603 ± 125 | 708 ± 260 | |||||||
| Rectus femoris | RMS (μV) | 87 ± 49 | 71 ± 43 | 84 ± 53 | 72 ± 40 | ||||||
| MVC (N) | 502 ± 397 | 445 ± 241 | 549 ± 352 | 421 ± 194 | |||||||
| Vastus lateralis | RMS (μV) | 92 ± 44 | 89 ± 43 | 94 ± 29 | 90 ± 62 | ||||||
| MVC (N) | 495 ± 195 | 523 ± 202 | 457 ± 94 | 434 ± 169 | |||||||
| 90% 1RM | Pectoralis major | RMS (μV) | 138 ± 56 | 121 ± 58 | 141 ± 39 | 144 ± 113 | |||||
| MVC (N) | 741 ± 449 | 637 ± 304 | 721 ± 290 | 704 ± 259 | |||||||
| Triceps brachii | RMS (μV) | 118 ± 47 | 107 ± 21 | 136 ± 48 | 143 ± 88 | ||||||
| MVC (N) | 801 ± 195 | 755 ± 166 | 751 ± 145 | 771 ± 225 | |||||||
| Rectus femoris | RMS (μV) | 96 ± 37 | 80 ± 37 | 93 ± 42 | 89 ± 69 | ||||||
| MVC (N) | 622 ± 415 | 574 ± 299 | 631 ± 308 | 564 ± 275 | |||||||
| Vastus lateralis | RMS (μV) | 93 ± 41 | 96 ± 29 | 91 ± 41 | 87 ± 49 | ||||||
| MVC (N) | 434 ± 167 | 469 ± 168 | 398 ± 154 | 394 ± 150 | |||||||
Values are means ± SD
RMS root mean square, MVC maximal voluntary contraction, MPLA morning trial ingesting placebo, MCAF morning trial ingesting caffeine, EPLA evening trial ingesting placebo, ECAF evening trial ingesting caffeine
Bold values indicate P< 0.05