Table 1 .
Voluntary and electrically stimulated isometric contractions of the m. quadriceps femoris measured before and immediately after two hours of treadmill walking (6.5 km·h −1 ) on a level gradient with no load (LW) or load carriage (25 kg backpack) (LC) (n=10)
| Variable | Condition | Pre-exercise | Post-exercise |
|---|---|---|---|
| MVC (N) | LW | 660 ± 155 | 617 ± 111 |
| LC | 692 ± 141 | 584 ± 126 ** | |
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| VA (%) | LW | 98 ± 3 | 96 ± 6 * |
| LC | 95 ± 5 | 91 ± 10 * | |
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| Doublet Peak Force (N) | LW | 174 ± 40 | 167 ± 43 |
| LC | 180 ± 41 | 166 ± 35 | |
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| Doublet Contraction Time (s) | LW | 0.186 ± 0.011 | 0.182 ± 0.012 * |
| LC | 0.191 ± 0.013 | 0.181 ± 0.008 * | |
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| Average Rate of Doublet Tension Development (N·s −1 ) | LW | 931 ± 175 | 912 ± 202 |
| LC | 937 ± 168 | 916 ± 172 | |
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| Doublet Half Relaxation Time (s) | LW | 0.096 ± 0.010 | 0.099 ± 0.015 |
| LC | 0.095 ± 0.008 | 0.092 ± 0.007 | |
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| Doublet Maximal Rate of Force Development (N·s −1 ) | LW | 1536 ± 332 | 1482 ± 371 |
| LC | 1588 ± 324 | 1450 ± 289 | |
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| Doublet Maximal Rate of Force Decrease (N·s −1 ) | LW | −1255 ± 239 | −1199 ± 347 |
| LC | −1308 ± 291 | −1238 ± 214 | |
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| 20:50 Hz Ratio (n=9) | LW | 0.84 ± 0.03 † | 0.84 ± 0.03 |
| LC | 0.88 ± 0.04 | 0.84 ± 0.04 * | |
Difference from pre-exercise measurement
*
P<0.05
**
P<0.01
Difference in pre-exercise measurement between LW and LC
†
P<0.05