While Monday marked the first day of summer, the heat and humidity have been upon us for some time. As temperatures continue to rise, greater stress is put on the body to remove heat and stay cool – even among the fittest athletes. Water and other fluids are essential not only to keep athletes safe while training during the summer months, but they also can enhance performance. So, before you step out the door for your next run, hop on a bike for a spin across town, or join your Boot Camp buddies for burpies and sprints, make sure you are up to speed on how to properly hydrate.
What Happens If You Don’t Drink Enough Fluids?
The body is largely made up of water which plays a number of roles, including joint lubrication, waste removal, and sweat production. Dehydration, a condition caused by the excessive loss of water from the body, can be detrimental to the performance and health of athletes.
Signs of dehydration include thirst, nausea, fatigue, dizziness, and difficulty concentrating. Once dehydration occurs, the volume of blood decreases due to fluid loss, limiting blood flow to skin, muscle, and the gastrointestinal tract. This hinders the body’s ability to remove heat, decreases muscle performance, and slows down the rate which energy (food) passes through the gastrointestinal tract. This effect on the gastrointestinal tract can lead to stomach discomfort and bloating, thus hindering the athlete’s will to consume additional fluid and energy.
Dehydration also increases heart rate, the perception of effort, and the depletion of muscle glycogen (a limited source of energy during activity).
Our body’s ability to stay hydrated depends on the balance between fluids consumed, and fluids lost in the form of urine, feces, breathing, and of course sweating. Fluids can be consumed in many forms, including water, as well as other liquids such as sports drinks, milk, tea, or other beverages. Foods such as fruits and vegetables also contribute to our hydration status due to their high water content.
Unfortunately, the amount of fluids an athlete needs isn’t one size fits all – it varies from one individual to the next. However, there are simple ways that an athlete can tell if he or she is properly hydrated.
Throughout the day leading up to activity, athletes should pay attention to cues such as thirst and urine color.
Thirst is typically a physiological mechanism that occurs at about a 1% fluid deficit, encouraging the individual to drink. If athletes are persistently thirsty, they may want to consider carrying fluids with them throughout the day.
Additionally, urine color should be pale or clear. If urine color is consistently darker than the shade of lemonade, athletes should drink more.
Another great way to track hydration during exercise is through the scale. A significant decline in performance has been noted after as little as a 2 percent loss in body weight from fluid loss. Hydration can be monitored during activity by measuring weight prior to and immediately following exercise (make sure you are dry when weighing). If greater than 2 percent body weight is lost, hydration practices need to be improved. On the flip side, weight gain should not occur during exercise, as this is a sign of excessive fluid consumption.
As summer continues, remember to pay attention to your cues: thirst, urine color and weight changes. Paying attention to these signs can keep you hydrated and allow you to keep doing the activities you enjoy most!
For more training and nutrition tips, visit www.ironman.memorialhermann.org
By Brett Singer, MS,RD,CSSD,LD, Sports Dietitian at Memorial Hermann IRONMAN Sports Medicine Institute in The Woodlands