Hydration The consequences of poor hydration‌. Too little? Dehydration- (>2% loss of body weight) can impair aerobic performance and may also affect cognitive performance. It is associated with heat stroke, 2 heat exhaustion and skeletal muscle cramps . Too much? Hyponatremia-a rapid drop in plasma sodium levels that occurs when fluid intake exceeds sweating rates. Most common in endurance events, with symptoms ranging from disorientation to 2 respiratory arrest.
Monitoring your hydration1 Are you thirsty? Is your urine a dark colour? Is your body weight substantially lower than yesterday? If you answer YES to any of these this may be a sign that you are not fully euhydrated.
Pre exercise- start exercise euhydrated -1
2
4 hours before: 5-7mL.kg (for a 70kg athlete slightly less than 500ml). -1 2 2 hours before: If still not hydrated‌3-5mL.kg (for a 70kg athlete approximately 300ml).
During exercise-prevent dehydration2 Fluid intake depends on: -1
1) Individual sweating rates (range from 0.4-1.8 L.h ) 2) Exercise duration 3) Drinking opportunities MUST be individualised and should consider drinks with electrolytes and carbohydrates to maintain fluid-electrolyte balance and aid performance.
Post exercise-replace fluid and electrolyte losses2 Consuming normal meals and drinks should restore euhydration. For quick and complete recovery 2 drink 1.5L of fluid for every kg of body weight lost . 2
Weighing yourself pre and post exercise can be a quick way to determine this.
References 1. Gatorade. Team Sports. 2014. [Online]. [Accessed 21 August 2014]. Available from: http://www.gatorade.co.uk/nutrition-and-training/team-sports 2. Sawka MN, Burke L, Eichner R, Maughan RJ, Montain SJ & Stachenfeld NS. (2007). Exercise and fluid replacement. Med Sci Sport Ex39(2), 377-390.