Hydration is a critical component of any sports performance or physical activity. Dehydration can lead to decreased performance, muscle cramps, fatigue, and even heat exhaustion. With summer approaching, it's important to discuss how to stay hydrated during exercise and sport. In this blog post, we'll discuss the warning signs of dehydration and heat-related illness, and what to do if you or someone on your team starts to experience them. We'll cover the latest hydration tips and strategies for athletes of all levels, including best ways to stay hydrated before, during, and after exercise. We'll also explore the importance of electrolytes, sports drinks, and water intake, and how to determine your individual hydration needs based on your body weight, activity level, and environmental conditions. Don't let dehydration hold you back this summer- read on to learn more about how to optimize your hydration for maximum sport performance!
Heat-related illness continues to be a significant threat to athletic performance and overall health. Most energy produced by the body is converted to heat and heat production is proportional to to body weight, while heat loss is proportional to body surface area. Heat dissipates through evaporation, radiation, conduction, and convection. Of these, evaporation is the primary mechanism through which heat is dissipated by the body. Heat acclimation is a process that the body uses to protect itself from heat-related illness. Physiologically speaking, acclimation is exhibited as an increase in sweat rate and a decrease in electrolyte loss. As a result of these processes, there is an increased resistance to dehydration and improvement in demand drinking. In general, the key to preventing heat illness is hydration. (DeFranco, 2008)
Here are signs of heat-related illness:
Heat cramps: poor acclimation to heat, negative sodium balance; twitches, painful spasms, sustained muscle contractions
Heat syncope: decrease in muscle contractions at end of activity and warm temperature, causes peripheral vasodilation, leading to decreased cardiac output and stroke volume; normal core body temperature, loss of consciousness, orthostatic hypotension
Heat Exhaustion: all above plus compromise of circulation and cooling mechanisms; fatigue, malaise, headache, nausea, vomiting, muscle cramping, profuse sweating, hypotension, tachycardia
Heat Stroke: all above plus physiologic failure of body to compensate for heat production; dry hot skin, confusion, elevated core body temperature, altered mental status, possible ataxia, seizure, coma, hyperventilation, tachycardia, hypotension
How to respond:
Heat cramps: passive stretching, appropriate dietary salt and fluid intake
Heat syncope: Lay on back in cool shaded environment, fluid replacement if underhydrated prior to onset of activity
Heat Exhaustion: stop play or activity, move to cool shaded climate, remove excess clothing, drink chilled fluids, moderate severity requires monitoring vital signs, IV fluids, and possible transfer to emergency facility
Heat Stroke: Emergency, life-threatening, urgent cooling first then medical facility, call 911 or nearest emergency department
Optimal hydration is a modifiable factor that should be attempted to help prevent the onset of heat illness. Thermoregulation is regulated by dehydration greater than 1% loss of fluid in the body. Body mass loss of 2% or greater during or after exercise leads to lack of fluid availability and compromise to thermoregulation. Fluid deficit of 3-4% elicited a performance decrement. Fluid replacement before, during, and after activity or sport should be available to promote rehydration. The athlete's diet and rehydration beverages should include sufficient sodium to prevent or resolve imbalances that occur as a result of sweat and urine loss. Rehydration plans need to replace fluid losses within a short time frame.
Calculate body mass change compared to at least 3 consecutive days of normal hydration baseline average; seek a medical professional to assess Sweat-Rate Equation
Assess first morning urine sample; adequate hydration: pale yellow color or clear; dehydration: darker yellow or amber in color, decrease in urine production; severe dehydration: very dark in color or brown with symptoms of altered mental status
recommendations of water intake
Males: 9-13: 2.7 L/day; 14-18: 3.3 L/day; >19: 3.7 L/day
Females: 9-13: 2.1 L/day; 14-18: 2.1 L/day: > 19: 2.7 L/day
Can include water, sports drinks, juices (use sports drinks that include electrolytes if activity is greater than 60-90 minutes)
Female/Male: 9-13 years
Female/Male: 14-18 years
Famale/Male: >19 years
before and during exercise
2-3 hours before: 17-20 fluid oz
15-20 minutes before: 7-10 fluid oz
During exercise: 7-10 fluid oz every 10-20 minutes
Water, sports drinks, juices
16-24 fluid oz per pounds lost of body weight, within 2 hours
Water, sports drinks, juice, other beverages
Monitor your body weight and urine color
Drink water throughout the day; drinking throughout the day is more effective in maintaining hydration levels than chugging a lot of water at once
Athletes and fitness enthusiasts need to drink water before, during, and after exercise to prevent dehydration
Consider electrolyte drinks when engaging in prolonged exercise (>60 minutes) or high-intensity training to help replace electrolytes lost through sweat
Eat hydrating foods such as fruits and vegetables with high water content, including watermelon, cucumber, celery, and citrus fruits to help maintain hydration
Avoid excessive caffeine and alcohol intake which cause dehydration
Use thirst as a guide as this is the body's natural mechanism that helps regulate hydration levels in the body
Be mindful of environmental factors such as heat, humidity, and altitude which can affect hydration levels
Seek a medical professional if you suspect a heat-related illness; any state of altered mental status or severe cardiovascular issues must seek emergency care; cool down first immediately and then go to emergency facility quickly
As an athlete, hydration is key to ensuring optimal performance and preventing injury. By implementing the hydration tips discussed in this blog, you can improve your performance and reduce the risk of dehydration and other related complications. Remember to pay attention to your body's thirst cues, monitor your urine color, and make sure you're consuming enough fluids before, during, and after exercise. By making hydration a priority in your training regimen, you can give yourself an edge in achieving and staying healthy. Don't forget to share these tips with your fellow athletes and sports enthusiasts to help them stay hydrated and performing at their best!
Your thoughts matter! I would love to hear your feedback on my latest post about hydration. Did you find the information helpful? Do you have any questions or additional tips to share? Leave a comment below and let's start a conversation. You're feedback will help me create more valuable content for you in the future. I'm looking forward to hearing from you!
Dr. Carlos Reyes
PT, DPT, SCS, MS, CSCS
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DeFranco MJ, Baker CL, DaSllva JJ, Plasecki DP, Bernard RB. Environmental issues for Team Physicians. The American Journal of Sports Medicine. 2008;36(11):2226-2237. doi:10.1177/0363546508325922
Hoogenboom B. Sports Nutrition and Performance Enhancement. lecture presented: 2023.