KIMBERLY A. VOLTERMAN¹, DANIEL R. MOORE²*
*Corresponding author
1. Child Health & Exercise Medicine Program, Department of Pediatrics, McMaster University, 1280 Main St. W., L8N 4J9, Hamilton, Ontario, Canada
2. Faculty of Kinesiology and Physical Education, University of Toronto, 55 Harbord St., Toronto, Ontario, M5S 2W6, Canada

Abstract

Athletes exercising under a variety of conditions are at risk for disruptions of body fluid balance, particularly hypohydration, primarily as a result of exercise-induced sweat loss. Even at low levels of hypohydration, athletes can experience negative effects on cardiovascular, thermoregulatory and cognitive function, as well as impairments in physical performance. Thus, in order to maintain euhydration, appropriate fluid and electrolytes must be ingested during activity. In the event that fluid deficits occur, ensuring proper rehydration prior to subsequent exercise bouts can be accomplished through the adequate intake of protein and electrolyte-containing beverages. Ultimately, an awareness of proper hydration strategies combined with practical methods to monitor hydration status will help athletes maintain optimal hydration and keep them performing at their best.

INTRODUCTION

What are hydration imbalances – and whom do they affect?
Water is vital for human survival and accounts for ~60% of the human body. In response to normal daily activities that include the ingestion of fluid in food and beverages counterbalance by evaporative losses through sweat and normal breathing, body water content in healthy children and adults typically fluctuates within a “normal” range (approx. ± 0.5%) wherein they are generally considered to be “euhydrated”. However, deviations outside of this range may occur resulting in states of “hyperhydration” (i.e. >0.5%) or “hypohydration” (<0.5%), which are the results of the active processes of water loss (“dehydration”) and gain (“rehydration”), respectively.

Hypohydration can be an issue not only for athletes participating or competing in warm external environments but also for those performing in warm indoor environments (e.g. basketball) and/or those requiring significant clothing/equipment (e.g. ice hockey, American football).
Regardless of sport modality, competition level (e.g. practice vs. competitio ...