Muscle metabolic responses during high-intensity intermittent exercise measured by P-31-MRS: relationship to the critical power concept

作者：Chidnok Weerapong; DiMenna Fred J; Fulford Jonathan; Bailey Stephen J; Skiba Philip F; Vanhatalo Anni; Jones Andrew M^*

来源：American Journal of Physiology - Regulatory, Integrative and Comparative Physiology, 2013, 305(9): R1085-R1092.

DOI：10.1152/ajpregu.00406.2013

• critical power
• W %26apos
• exercise tolerance
• interval training
• fatigue
• performance
• intermittent exercise

We investigated the responses of intramuscular phosphate-linked metabolites and pH (as assessed by P-31-MRS) during intermittent high-intensity exercise protocols performed with different recovery-interval durations. Following estimation of the parameters of the power-duration relationship, i.e., the critical power (CP) and curvature constant (W%26apos;), for severe-intensity constant-power exercise, nine male subjects completed three intermittent exercise protocols to exhaustion where periods of high-intensity constant-power exercise (60 s) were separated by different durations of passive recovery (18 s, 30 s and 48 s). The tolerable duration of exercise was 304 +/- 68 s, 516 +/- 142 s, and 847 +/- 240 s for the 18 s, 30 s, and 48 s recovery protocols, respectively (P %26lt; 0.05). The work done %26gt;CP (W (%26gt;CP)) was significantly greater for all intermittent protocols compared with the subjects%26apos; W%26apos;, and this difference became progressively greater as recovery-interval duration was increased. The restoration of intramuscular phosphocreatine concentration during recovery was greatest, intermediate, and least for 48 s, 30 s, and 18 s of recovery, respectively (P %26lt; 0.05). The W-%26gt;CP in excess of W%26apos; increased with greater durations of recovery, and this was correlated with the mean magnitude of muscle phosphocreatine reconstitution between work intervals (r = 0.61; P %26lt; 0.01). The results of this study show that during intermittent high-intensity exercise, recovery intervals allow intramuscular homeostasis to be restored, with the degree of restoration being related to the duration of the recovery interval. Consequently, and consistent with the intermittent CP model, the ability to perform W-%26gt;CP during intermittent high-intensity exercise and, therefore, exercise tolerance, increases when recovery-interval duration is extended.

• 出版日期2013-11
• 单位南宁师范大学