Claytor, R. P (May, 1986). Selected cardiovascular sympathoadrenal and metabolic responses to one-leg exercise training. Dissertation Abstracts International-A, 46, 3283.

The purpose of this study was to determine whether exercise training of one leg altered cardiorespiratory, metabolic, and sympathoadrenal responses to submaximal exercise in a previously nontrained leg. Ss trained one leg (TR) at 85-90% of one-leg VO2max for three weeks (13 training sessions). Following a battery of post-training tests, the contralateral leg (NTR) was exercised on five consecutive days. Measurements were taken on the first, third and fifth days of exercise. Before one-leg training, mean one-leg VO2max values compared between legs, were not significantly different. After one-leg training, VO2max in the TR leg increased 14% (p < 0.0001), whereas VO2max in the NTR leg increased less than 3% (p > 0.2). Two-leg VO2max was increased 8.5% after one-leg training (p > 0.005). One week of exercise training resulted in significant reductions in HR, blood LA, and plasma epinephrine (E) and norepinephrine (NE) responses during exercise with each leg separately. Within five consecutive days of exercise, HR, blood LA, and plasma E and NE responses to exercise decreased approximately 7%, 27%, 50%, and 40%, respectively, during exercise with each leg separately. These data gave no indication of an attenuated HR, blood LA, or plasma E and NE response to the initial bout of exercise with the NTR leg suggesting that peripheral circulatory, neural, and metabolic adaptations to exercise influenced the initial physiological responses to exercise. However, the occurrence of small but consistent attenuations in the physiological responses was significantly attenuated (p < 0.05) on the third day of exercise when the TR and the NTR legs were compared to the same absolute workrate on the third and fifth days of exercise with the NTR leg suggest that central regulatory factors may have affected the exercise training response.

Implications. When one-leg training was completed and adaptations noted, switching to the untrained leg did not reveal any transfer of training effect from the trained leg. The untrained leg produced untrained physiological and sympathoadrenal responses. When both legs were exercised, the trained and untrained legs together, there was some transfer but nowhere near that achieved for the single trained leg. This indicates that physiological adaptations to training are not "general" cardiovasacular or respiratory adaptations, but are dictated by the trained state of the muscles. Physiological adaptations are only appropriate for the exercises in which they are trained. When the single untrained leg was exercised, there was no "carry-over" from the trained physiological state associated with the trained leg. The "trained heart" was not activated by the untrained limb.

The belief that "general" and "cross-training" exercises are valuable for specific competitive performances is refuted by this investigation. If an athlete is going to perform in a certain manner in a competition, then training exercise intensity, duration, and form need to mimic the competitive demands. Otherwise, training fitness will not be employed in the sport competition. For example, swimming coaches set a substantial amount of training at 75%, 85%, and 95% of race pace/intensities. "Percentage" training of that type is useless for competitions that are to be performed at a particular "100% pace/intensity" because for each varied exercise intensity, the physiological demands are specific and differentiated. [Note: This abstract pertains to physiological adaptations that occur with conditioning. Its implications do not cover neural adaptations or strategic plans.]

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