Resumen de Postexercise Cold-Water Immersion Does Not Attenuate Muscle Glycogen Resynthesis.
Warren Gregson, James P. Morton, Robert Allan, Chang Hwa Joo, Susan Holden, Sarah Waldron, Padraic J. Phibbs, Iain Campbell, Dominic Doran
AB Purpose: The aim of this study was to test the hypothesis that postexercise cold-water immersion (CWI, via its associated reductions in skeletal muscle blood flow) attenuates muscle glycogen resynthesis during short-term recovery from exhaustive exercise. Methods: In a repeated-measures design, nine recreationally active men performed an exhaustive glycogen depleting cycling protocol (consisting of intermittent exercise the night before and steady-state exercise on the subsequent morning of the main trial) followed by 10 min of lower-limb CWI (8[degrees]C) or remained seated in normal ambient conditions (CONT). Subjects were fed carbohydrate (CHO) at an ingestion rate of 0.6 g[middle dot]kg-1 body mass at 30 min postexercise and at 1, 2, and 3 h postexercise. Results: Reductions in thigh skin temperature and muscle temperature during postexercise recovery were greater in CWI compared with CONT (P < 0.01). In addition, norepinephrine and blood glucose concentrations were increased and decreased, respectively, during recovery in CWI compared with CONT (P < 0.01). Postexercise muscle glycogen (CONT and CWI postexercise = 76 +/- 43 and 77 +/- 26 mmol[middle dot]kg-1 dry weight [dw], respectively; mean +/- SD) progressively increased (P < 0.01) during recovery, although rates of resynthesis did not differ (P = 0.719) between conditions (CONT and CWI 4 h postexercise = 160 +/- 34 and 157 +/- 59 mmol[middle dot]kg-1 dw, respectively). Total glycogen synthesis during recovery was comparable (CONT and CWI = 83 +/- 43 and 79 +/- 58 mmol[middle dot]kg-1 dw, respectively). Conclusions: Postexercise CWI does not attenuate muscle glycogen resynthesis rates during short-term recovery even when CHO availability is considered suboptimal. Athletes who regularly incorporate CWI as a recovery strategy to alleviate symptoms of exercise-induced muscle damage should therefore not be concerned with potential negative effects of the associated reductions in muscle blood flow on the restoration of muscle glycogen stores
