Hydration Guidelines for Runners and Walkers
Even the best managed race event courses have been known to run out of water or cups at an aid station. Runners and walkers in the back of the pack are more vulnerable to aid stations running out of water. In this article we discuss the basic hydration guidelines for runners and walkers, and the reasons why Boise RunWalk coaches recommend you carry your water during your training as well as your long distance event. Take in fluids strategically at planned intervals, and refill your water bottle at water stations and practice throughout the season.
Why people DON’T DRINK enough water?
Common reasons people don’t drink enough fluids:
- It will make me go to the bathroom too frequently
- Peeing causes lost time, especially waiting in line
- Drinking makes my stomach upset
- I’m not thirsty
Hydration Guidelines: Examples
A person who is 125 pounds and is exercising for 15 minutes each day, is not pregnant, is not breastfeeding, does not live at a high altitude, lives in a dry climate, drinks no alcohol, lives where the weather is not very hot or very cold, and is not sick with fever or diarrhea should have 72 ounces of water a day, or 2.25 quarts. In a healthy diet, about 20 percent of this person’s needed water may come from the foods they eat, thus if they eat a healthy diet, they can drink 57 ounces (1.75 quarts) water a day.
A person who is 235 pounds and is exercising for 15 minutes each day, is not pregnant, is not breastfeeding, does not live at a high altitude, lives in a dry climate, drinks no alcohol, lives where the weather is not very hot or very cold, and is not sick with fever or diarrhea should have 127 ounces of water today, or 4 quarts. In a healthy diet, about 20 percent of this person’s needed water may come from the foods they eat, thus if they eat a healthy diet, they can drink 100 ounces (3 quarts) water a day.
Why carry your own water?
Hydration is a key strategy, and with Boise RunWalk you will learn to consume fluids strategically during your workouts so that come race day, your body is ready to go the distance. But many people feel that since we place water coolers on the practice routes, and since race events have periodic water stations, that they do not need to carry water.
At Boise RunWalk, we place water coolers every now and then along the practice route, and we want you to replenish your carried water supply at these coolers. This allows you to setup regular hydration intervals every 15 to 20 minutes, approximately. Our coolers are not really set at 15 to 20 minute intervals, because walkers and runners all have difference paces. Walkers have a walk pace that ranges between 14 to 20 minutes per mile. Runners run in a range between 6 and 14 minutes per mile.
At race events, water stations are setup typically every couple miles, and this will not adequately support your strategic hydration intervals. Your coaches recommend implementing suitable intervals, and replenishing your water supply at the water stations. And here is another big reason to carry your own water… for when a water station runs out of water. Trust us, this happens, especially for walkers and runners at a slower pace. We coach you to be self-reliant, and use the stations to fill up your bottle.
An important hydration guideline for runners and walkers, is to understand your hypothalamus, in your brain. The hypothalamus regulates the sensation of thirst in your body. By the time your hypothalamus makes you “feel” thirsty, you are probably around 1% dehydrated (1% of your body weight). In your Boise RunWalk training program, we coach you to practice drinking at regular intervals before you feel thirsty because at that point, it can be difficult to regain necessary hydration.
Prevent thirst with these hydration guidelines
Another important guideline is to prevent feeling thirsty, especially during endurance and extended workouts. Drink water and a sports drink at timed intervals. During exercise and heat stress, your body demands more water. Do not wait until you feel thirsty but instead, begin your hydration intervals shortly after the start of your workout and event.
Your blood acts as a heat regulator
When we exercise or body serves as a heat regulator while facing two competing demands:
(1) muscles require oxygen to sustain energy metabolism
(2) metabolic heat must be transported by the blood from the deep tissues to the skin.
Your blood acts as a heat regulator by transporting heat to the skin for evaporation, but this blood is taken from other organs such as the stomach and muscles. Thus, the blood heading to the skin is not available to deliver its oxygen and nutrition to your working muscles. Your working muscles then generate more heat, especially without adequate hydration. Our internal temperature can climb two full degrees during continuous cardio exercise, and to help your body act as a better heat regulator, stay adequately hydrated.
As we sweat, the sweat evaporates off our skin, and this cools us down. However, this process does not work well if the relative humidity is high. When the humidity is high, sweat does not evaporate nearly as well. It only rolls off the body in heavy beads. When sweat cannot evaporate well, body temperature continues to rise and our body sweats even more to offset this internal temperature elevation. Excessive fluid loss can occur and blood volume begins to diminish and thicken. Anytime we dehydrate close to 2% of our total body weight, our core temperature rises, our heart rate increases, and our central nervous system will begins to show ill effects. And your performance will suffer.
Fluid loss and body size
Size of the person is positively correlated to fluid loss. Thin people can generally tolerate heat better than heavier people. Extra weight means more work resulting in more heat production. Then, more blood diverted to the skin to dissipate body heat, resulting in less blood to carry oxygen to the muscles for performance. A fitter person has a better thermal regulatory system which dissipates heat faster. Acclimatization to warmer temperatures takes approximately 10 days for your body to adjust. The bottom line is, hotter the temperature and the longer the activity, the greater the fluid loss. Clothing fabric types can also affect heat loss by trapping moisture next to the skin making it tougher for it to evaporate.
The kinds of fluids to drink
Cool water is absorbed faster than warm water. Fluid replacement drinks are absorbed up to 30% faster than straight water. Sports drinks should not exceed 6-7% carbohydrate concentration. Stay away from carbonated drinks because CO2 bubbles can cause stomach upset. Be cautious with high-sugar drinks. And very importantly, learn what kinds of fluids are best for you DURING the training season. Do not wait until race day to begin a strategic fluid replacement program. Lastly, always consult with your Boise RunWalk Coaches.