Hydration is always an important factor in health and during physical activity it becomes even more crucial. With the summer heat rising active individuals need to be especially on top of their fluid intake. Fluid is lost at a higher rate during physical activity due to increases in breathing rate and sweating. Dehydration can occur quickly during physical activity without proper replenishment, especially in the summer months and/or at altitude.
Even small losses in total body weight can indicate dehydration and even slight dehydration can negatively affect performance and increase risk for injury. Dehydration decreases the volume of circulating blood thereby decreasing the oxygen provided to working muscles and simultaneously reduces the flushing of harmful exercise by-products from those muscles. Together, these dehydration related outcomes lead to quicker exhaustion as well as increased risk for injury.
The best way to prevent dehydration is to consume enough fluids before, during, and after activity. It is easy to forget that we are losing so much fluid when we are in middle of enjoying an activity. Sometimes you may wait to drink anything until you feel thirsty. Unfortunately, thirst is usually not sensed until a large amount of fluid has been lost and your performance has already been compromised.
To maintain hydration you should follow a daily hydration routine on top of including additional fluids during and after physical activity. The National Academy of Medicine now recommends that adult men consume 15 cups of fluid per day and that adult women consume 11 cups. However, we’re not only receiving fluid in the form of liquid water, there is fluid in other beverages as well as in the food that we eat. Therefore, rather than obsessing about drinking the exact correct amount water each day, choose to drink water with and between your meals and pay attention to your urine color to assess hydration status. Our urine should appear with a slight yellow tint, if you notice a deeper color of yellow this is an indicator to increase you fluid intake.
On top of our regular fluid intake, during and after activity we should be increasing intake to make up for the fluid loses brought about via exercise. Shoot for around 16 ounces an hour during lighter activities and closer to 32 ounces an hour in vigorous activities or in hotter environments/at altitude. Remember to start hydrating early on in the activity to stay ahead of dehydration throughout. In order to ensure appropriate fluid replenishment post-exercise you’ll need to know how much fluid you’ve lost during a bout of physical activity; for every pound lost drink 20-24 ounces of fluid.
The amount of fluid you drink during activity is not the only thing to consider but also what you’re choosing to rehydrate with. For activities lasting an hour or less water is best. However, as activity duration increases water is no longer a complete enough fluid to replenish everything that is being lost during the activity. Electrolytes (sodium chloride, potassium, magnesium, and calcium) are lost through sweat and glucose is lost as muscular glycogen stores are burned for fuel during longer lasting physical activity. Therefore, during activity lasting an hour or more rehydrating fluids should contain electrolytes and sugar.
Popular sports drinks are adequate in rehydrating for longer durations of exercise, however they’re often made with unnatural sugars, unnecessary additives, and harmful artificial coloring. For ideas in making your own, high-quality hydrating beverage visit DIY Hydrating Recipes. Happy hydrating!