The purpose of the present study was to determine whether or not the combination of normobaric hypoxia and exercise training would enhance adaptations in skeletal muscle over and above that which occurs with the same amount of training under normoxic conditions. Also investigated was the effect of such training conditions on performance as assessed by V0_2max and maximal aerobic capacity (MAC). Ten males performed unilateral cycle ergometry training
3 times per week for 8 weeks so that one leg was trained under normoxic conditions and the other while breathing an hypoxic gas mixture (FI0_2= 13.5%; equivalent to an altitude of 3,292 meters). Absolute power output was kept constant for both conditions and subjects performed both continuous (75% pre-training maximal power output) and interval (100% pre-training maximal power output) training. Needle biopsies were taken from the vastus lateralis of both legs to assess pre- and post-training differences in morphometric and biochemical data. Performance measures included V0_2max and MAC (time to fatigue at 95% pre-training maximal power output) for each leg. Significant increases in V0_2max (p <0.05) occurred in
both legs with higher peak ventilation and blood lactate concentrations (p <0.05) post-training. Marked improvements (p <0.05) in MAC were also seen with an increase of 402% in the normoxically-trained leg and 513% in the hypoxically-trained leg. Citrate synthase (CS), succinate dehydrogenase, and phosphofructokinase activity was significantly (p <0.05) higher in both legs following training with a significantly greater (p <0.05) increase in CS in the hypoxically-trained leg. There were no differences in capillary/fiber ratio, capillary density,
fiber area, fiber type, and mitochondrial volume density for either condition, pre- or post-training. It is concluded that hypoxia enhanced the muscle oxidative capacity (as marked by cs activity) but was unable to improve performance over and above that which occurs with the same training at sea level. / Thesis / Master of Science (MS)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/23253 |
| Date | 08 1900 |
| Creators | Melissa, Lori |
| Contributors | MacDougall, J. D., Human Biodynamics |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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