Cold water submersion attenuates post-submersion aerobic performance and orthostatic tolerance irrespective of partial rehydration with water.

Purpose: This study examined the independent effects of cold-water submersion and a rehydration strategy on an aerobic endurance performance and orthostatic tolerance following a four-hour dive in cold water (10°C).

Methods: Nine male subjects completed a control (CON) performance and lower-body negative pressure test (LBNP) and two water immersion visits with either no rehydration (NR) or a post-immersion rehydration (RH) with 1 L of water. Following submersion, subjects ran to exhaustion and submitted to LBNP.

Effect of rehydration schedule after four-hour head-out water immersion on running performance and recovery.

Introduction: Head-out water immersion (HOWI) results in diuresis, which could potentially limit performance after egress to land. We examined the effect of rehydration on endurance, cardiovascular stability, and overnight recovery following a four-hour thermoneutral HOWI on 12 subjects.

Methods: Twelve males completed a crossover design consisting of no hydration, replacement of fluid loss during immersion (RD), and replacement of fluid after the immersion period (RA).