The Importance of HYDRATION
by Danielle Van Schaick, R.D.
Dani Health & Nutrition
What does water do for me? Water has many important functions in the body including:
• Carrying oxygen and nutrients to working muscles and taking away wastes to be eliminated in urine
• Sweat production so that body temperature can be regulated
• Important in normal maintenance of blood pressure and heart rate
• Organ cushioning and joint lubrication
• The body is 65-75 % water
• Water can be helpful in weight loss because it fills you up
• Needed for storage of energy (glycogen and creatine) in the muscle
What are the signs of dehydration?
• Increased body temperature
• Rapid heart beat (loss of 2 lbs of fluid increases heart rate by 8 beats/minute)
• Decreased concentration
• Cramping, nausea, headaches
• Impaired performance (1 % dehydration can cause 10 % reduction in performance!)
i.e. A 1.5 lb wt. loss in a 150 lb athlete can cause 10 % performance reduction.
How much should I drink every day?
In general, you should drink at least 8-10 cups a day in addition to drinking during exercise.
Another way to calculate needs is 1 litre of fluid/1000 kcal you eat.
What if I don’t like the taste of water?
Water is an excellent choice if you are watching your caloric intake. It is also inexpensive and readily available. But, if you don’t like the taste of water try adding a splash of juice to water for flavour or have seltzer, herbal teas, broth-type soups, sports drinks, decaffeinated tea, or soft drinks without caffeine.
How can I remember to drink enough?
• Try carrying a water bottle with you every where you go
• Try a mouthful of water after each bite of food you take
• Try filling a 1.5 L bottle and drink it throughout the day (6 cups)
How much should I drink during exercise?
Before: Drink 2 cups (500 ml) of fluid in the hour before you exercise
During: Try to drink 500 mL-1 L of fluid per hour of exercise. Sip frequently (1/4 cup) every 5-10 minutes. Drinks need to be dilute: no more than 6-8% carbohydrate (Gatorade: 6%, Eload: 6%, Powerade: 8%, Juice: 10%, Pop: 11%)
After: Drink 3 cups (750 ml) for every pound of sweat you lose during training. (Weigh yourself before and after exercise to determine how much sweat you lose) Remember, thirst is not a good indicator of hydration. You may already be dehydrated by the time you feel thirsty!
Is it really worth carrying that extra weight of water during my runs?
The short answer is YES! Water is the most powerful ergogenic aid. It has the biggest potential to improve your performance and give you the edge over the competition. During long runs, if you can’t carry all your fluids try planting water bottles along your running route. Get used to wearing a water belt or “camelback”.
What if fluid before/during activity makes me feel sick?
If you get cramps or a “sloshy” feeling when you drink it may be due to dehydration. If you are well hydrated before exercise starts your stomach may absorb the fluids easier. Try to drink at least 8 cups during the day including 2 cups in the hour before exercise. This will help your stomach absorb the fluids faster during exercise.
Is it possible to drink TOO much?
Yes. This is rare but it does happen, especially in prolonged (> 2 hrs) high intensity exercise in hot weather. When you drink too much it dilutes the sodium in your blood and it may cause headaches, nausea, dizziness, poor performance, and high blood pressure.
To prevent overhydration, do not drink more than 1 L/hr of plain water during exercise. Take a sport drink if you need more fluids. With exercise > 1 hr, use a sports drink that contains sodium (eg. Eload, Gatorade, Allsport).
Danielle Van Schaick BASc, RD, CPT
Registered Dietitian, Lead Dietitian
Danielle is a private practice dietitian with a strong background in health, nutrition and fitness. She holds an Applied Human Nutrition Degree from the University of Guelph and successfully completed a Dietetic Internship with Vancouver Island Health Authority (VIHA).
Registered as a Dietitian (RD), Danielle has studied the human body and is considered one of Canada’s leading experts in food and nutrition. She offers one-on-one nutrition counseling to individuals, families, and groups.