Dehydration Does Not Affect Delayed Onset Muscle Soreness After Muscle Damage

INTRODUCTION: Muscle-damaging exercise initiates an inflammatory cascade that contributes to the development of delayed onset muscle soreness (DOMS), which typically resolves within 24 to 72h. Although dehydration is common among active young adults and has been associated with greater severity of exercise-induced muscle damage, its role in modulating the resolution of soreness (indicative of inflammatory response) during recovery remains unclear. PURPOSE: To examine the effect of fluid restriction during 72hr recovery period on DOMS following exercise-induced muscle damaging exercise in young active adults. METHODS: Active men (n=6, 20±3yr, 173.6±8.1cm, 78.9±12.2kg) and women (n=2, 20±1yr, 162.6±3.6cm, 69.9±3.1kg) completed two identical bouts of unilateral maximal eccentric knee-extension exercises (ECC; 10 × 30reps) and followed by a 72hr recovery period under either euhydrated or dehydrated conditions. These two conditions were randomized and counterbalanced with 28-d apart. Participants completed either 72hr euhydration (EUH) or 72hr DEH (24 h no fluid + 1.5 L/day for 48hr. A 4-day hydration baseline was implemented before each condition. To control nutritional intake, participants were instructed to consume preplan diets focused on food with low moisture contents during the hydration baseline, and the 72hr recovery period for both conditions. DOMS was assessed via visual analog scale (VAS) at PRE, immediately (IP), 1hr, 24hr, 48hr, and 72hr post ECC. A two-way repeated ANOVA was used to analyze DOMS. RESULTS: A significant (p < 0.05) main effect of time was observed. DOMS increased from PRE (0.1 ± 0.2) to IP (5.1 ± 3.2, p=