IS LEG STRENGTH A LIMITING FACTOR IN VO2PEAK OF MEN AGED 70???80 YRS?

Abstract

It is well established that regular endurance exercise can lead to improvements in VO2max of older individuals. The effect of resistance training on increasing VO2max in older individuals is less clear. Untrained subjects are usually unable to achieve a true VO2max on a cycle ergometer due to non-cardiovascular factors such as leg strength. PURPOSE To determine if leg strength training will increase VO2peak in older men and if during detraining the relationship between leg strength and VO2peak is maintained. METHODS Twenty two older men (70–80yr) participated in sixteen weeks of training and four weeks of detraining. Eleven men were randomly selected in the leg strength training group (EX) and eleven in the non-training control group (CO). VO2peak was assessed by cycle ergometer until volitional exhaustion. Maximal leg strength was assessed by determining the maximum amount of weight that could be lifted for one repetition (1RM). Strength testing and training took place on an incline squat and consisted of three sets of six to ten repetitions @ 70–90% of 1RM three times per week. Leg strength and VO2peak was assessed in all subjects every four weeks of training and after four weeks of detraining. RESULTS Maximal leg strength (1RM) significantly (p < 0.05) increased every four weeks of training resulting in a 95±0.6% increase in 1RM after 16 weeks. Peak VO2 significantly (p < 0.05) increased after 12 weeks of training resulting in an 8±0.8% increase after 16 weeks. After four weeks of detraining leg strength remained 77±2.3% (p < 0.05) above pre-training values while VO2peak had returned to pre-training values. There was no significant change in leg strength or VO2peak for the CO group over the 16 weeks of training or the four weeks of detraining. CONCLUSION The return of VO2peak to pre-training levels following four weeks of detraining was despite the retention of 77±2.3% of gains in leg strength acquired during the sixteen weeks of training. This suggests that factors other than leg strength may have been responsible for the gain and subsequent loss in VO2peak of the older men.