Cold-water immersion decreases cerebral oxygenation but improves recovery after intermittent-sprint exercise in the heat


This study examined the effects of post-exercise cooling on recovery of neuromuscular, physiological, and cerebral hemodynamic responses after intermittent-sprint exercise in the heat. Nine participants underwent three post-exercise recovery trials, including a control (CONT), mixed-method cooling (MIX), and cold-water immersion (10°C; CWI). Voluntary force and activation were assessed simultaneously with cerebral oxygenation (near-infrared spectroscopy) pre- and post-exercise, post-intervention, and 1-h and 24-h post-exercise. Measures of heart rate, core temperature, skin temperature, muscle damage, and inflammation were also collected. Both cooling interventions reduced heart rate, core, and skin temperature post-intervention (P<0.05). CWI hastened the recovery of voluntary force by 12.7±11.7% (mean±SD) and 16.3±10.5% 1-h post-exercise compared to MIX and CONT, respectively (P<0.01). Voluntary force remained elevated by 16.1±20.5% 24-h post-exercise after CWI compared to CONT (P<0.05). Central activation was increased post-intervention and 1-h post-exercise with CWI compared to CONT (P<0.05), without differences between conditions 24-h post-exercise (P>0.05). CWI reduced cerebral oxygenation compared to MIX and CONT post-intervention (P<0.01). Furthermore, cooling interventions reduced cortisol 1-h post-exercise (P<0.01), although only CWI blunted creatine kinase 24-h post-exercise compared to CONT (P<0.05). Accordingly, improvements in neuromuscular recovery after post-exercise cooling appear to be disassociated with cerebral oxygenation, rather reflecting reductions in thermoregulatory demands to sustain force production. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Scandinavian Journal of Medicine and Science in Sports