Staying hydrated while endurance training in the heat is NOT as easy as it seems! What is the correct amount of water to consume for your body size? for your activity? for the time of day?
Did you know?… As little as 2% dehydration affects athletic performance, cardiovascular system, and the thermoregulatory system? 3% dehydration causes cardiovascular and thermoregulation affects. 4-5% dehydration can place you at risk for heat exhaustion and heatstroke.
At B-Fit Physical Therapy, we educate you to keep you safe! When you have a goal for cycling 250 miles this week, we want you safely hydrated through each of those rides, especially that last one! 50% of athletes start their first day of summer practice already dehydrated.
Weight charts and hydration assessments are the keys. Remember this anacronym…WUT! Weight, Urine, Thirst (WUT)! Track your weight loss. Regularly assess how dark the color of your urine. Track your thirst frequency.
At a minimum, weight charts should be implemented during the heat acclimatization time period, when exertion heat illness risk is highest. Start weighing yourself at the same time each day (without shoes and socks). Performance weight charts start 14 days after you have acclimatized to the heat. Track your weight loss each day for a week’s worth of training. Weigh yourself before AND after the training event. Record the Absolute Weight Loss for each day’s event and across the week.
Absolute Weight Loss= pre-activity weight minus the post-activity weight
1 lb = 16 oz of water
Percent Dehydration Within Event
Percent dehydration = (pre-activity weight minus post-activity weight / pre-activity weight ) x 100
Percent Dehydration Across the Week of Events
Percent dehydration weight = (baseline weight - post activity / baseline weight ) x 100
By NCAA standards, 27% loss indicates exertion heat exhaustion.
Thermoregulation is a fancy scientific term, but the bottom line is, you’ve got to keep yourself hydrated to keep your body functioning healthy, if not optimally, when training! Be Safe! B-Fit!