We all know we should drink plenty of fluids every day to stay fully hydrated, but how much is enough during exercise? The Sports Dieticians Association’s guidelines recommend that you should drink approximately 2 litres of fluid every day.
How Much Fluid Does Our Body Need During Exercise?
Always start every exercise session well hydrated.
Drink 300-500ml of fluid in the 15 minutes prior to your workout.
Aim to drink 150-250ml every 15 minutes to offset fluid losses – drinking smaller volumes more frequently minimises stomach discomfort.
Remember, the more you sweat, the more you need to drink.
How much fluid you need depends on how much you lost. Try to drink 1 litre of water for every hour of exercise.
What Should I Drink?
Don’t overlook water as a great fluid choice. Water is easily accessible and kilojoule-free – a great choice if you are watching your weight! Sports drinks are suitable during and after longer, higher intensity exercise sessions as they contain carbohydrates (4-8%) and electrolytes to aid fluid absorption. Carbohydrates provide an added energy source and electrolytes replace salts lost in sweat. Choose a sports drink which is formulated to aid hydration and performance.
Are energy drinks the same as sports drinks?
Most energy drinks contain caffeine, often more than you would find in a cup of coffee. Large amounts of caffeine can increase the risk of dehydration. Therefore, avoid energy drinks before and after exercise.
Target heart rate
Your heart rate is the key to knowing if you are exercising at the right intensity for the exercise program you are following. You use a given percentage of what’s known as your maximum heart rate (MHR) when you exercise. To work out your MHR, simply subtract your age from 220. For example, at age 35 your MHR would be 185.
Find your personal heart rate zone.
Target heart rate chart
Many exercise machines at fitness centres enable you to measure your heart rate. You can also buy a heart monitor that you wear when exercising.
A simpler approach is to count your pulse for 10 seconds and multiply by six to get the per-minute rate. During a workout begin your count within five seconds of pausing. Another way of knowing what level of intensity you are working at is by understanding the changes in your breathing and body temperature:
- Low – no noticeable increase in breathing and heart rate with constant movement
- Moderate – will cause a noticeable increase in breathing and heart rate and may cause a light sweat
- High – will cause hard breathing/puffing and panting
Your appropriate exercise intensity, and therefore target heart rate, should be determined by a Fitness Australia registered fitness professional.