Nutrition

Summer Hydration Strategy

By Alexis Williams, RD

The weather is steamy and you're left wondering, how should I be hydrating my body?

For starters, aim to drink enough fluids to produce pale-lemonade coloured urine. On average this is between 1.5-4L per day, which is highly variable based on gender, age, muscle mass, sports and activity level. That's why urine output colour gives you more individualized advice.

During activities, there is a substantial variation in sweat levels. Some individuals lose as little as 400mL per hour whereas others can lose up to 2L per hour. The dangers of dehydration and overhydration (although rare) exist and giving blanket hydration guidelines can make this worse.

A good tool for active people is to measure your sweat rate during exercise. To learn how to do this, visit www.transtionhealth.ca “Tools” section and click on the sweat rate test chart. Basically it will involve weighing yourself before and after a training session and measuring how much fluid you consume. Once you know this info, test it in varying weather conditions and use it as a starting point for planning your hydration needs.

Here are some other common Q & A about hydration, from the Coaching Association of Canada's Sport Nutrition Advisory Committee (2006).

Question: If we need at least 1.5 – 4 litres of ?uids daily, which ?uids can I count to meet my needs?

Answer: You can count water, milk, soups, juices, and sport drinks. In fact, count most ?uids that you drink in a day towards your overall ?uid needs. Even the ?uids found within fruits and vegetables will contribute towards your ?uid consumption. However, fruit drinks and pop are less effective for hydration. The high sugar content will draw water into the digestive system to dilute the sugar.

Recent research suggests that caffeinated beverages (i.e., coffee and tea) are less dehydrating than what was once believed, and therefore, could be counted towards your total ?uid consumption. However, remember that caffeine is a stimulant drug, so moderation is a good thing.

Question: I'm often thirsty. Is it okay to drink lots of juice?

Answer: Thirst is a sign that you are mildly to moderately dehydrated. Although juice provides ?uid that you need, it also contains calories, which you may or may not need. Only you can decide if your body needs the ?uid calories found in juice. On the plus side, most juices also contain essential nutrients, such as vitamin C and potassium. You could consider diluting your juice with extra water or sparkling water so that you drink more water and less juice. Regardless, when choosing a juice make sure you are reaching for one that is not sweetened with sugar. “Unsweetened” or “100% juice” should be visible on the label. Avoid fruit drinks, punches, beverages, and cocktails that contain a substantial amount of added sugar. By the way, adding freshly squeezed lemon or lime to water is an effective way to enhance the ?avour of plain water.

Question: I've been told not to have a sport drink before, during, or after my soccer games. Is it good advice to avoid sport drinks?

Answer: There are several situations when a sport drink (i.e., carbohydrate, electrolyte solution) is bene?cial for athletes. Sport drinks can help store extra energy when an athlete is carbohydrate loading during the days before a competition. Secondly, a sport drink can provide available energy when consumed as part of a snack before training or competition. Furthermore, a sport drink during exercise helps to maintain your energy, focus, and skill level. And ?nally, consuming a sport drink right after training can speed up your body's ability to restore energy. By the way, sport drinks provide more than just energy, they obviously contain ?uid which is extremely important for peak performance. As well, the electrolytes (i.e., sodium, potassium) that your body loses during exercise need to be replaced too.

Alexis Williams is a Registered Dietitian and Personal Trainer in Burlington Ontario. She is an avid athlete, recently completing Ironman Louisville. Visit her website www.transitionhealth.ca to contact her for online, telephone-based or in-person nutrition coaching services.