Drinking during exercise – what to drink and when

Summer is on it’s way, so often our performance level drops because of our lack of knowledge around hydration. The larger the volume of fluid in your stomach, the faster it is emptied into the intestines and so the faster it replaces fluid losses in your body. That!s why it is best to drink as much as you comfortably can early on in your workout , then to continue topping up with frequent drinks.

Hypotonic or isotonic?

Hypotonic – More dilute, it is absorbed into the body faster than water (fewer particles per 100ml than body fluids).
Isotonic – Compromise between hydration and refueling, absorbed into body at same rate or faster than water (same number of particles per 100ml than body fluids).

Exercise Conditions Drink
30 minutes Nothing, water
Low/Moderate intensity 1 hour Water, hypotonic or isotonic sports drink
Low/moderate intensity 1hour in hot conditions Hypotonic sports drink
Strenuous/High intensity 1-2 hours Hypotonic or isotonic sports drink
Strenuous/High intensity >90 minutes or >1 hour in cool Hypotonic or isotonic sports drink
conditions carbohydrate (glucose polymer) drink**

**If you are exercising strenuously for more than 90mins or under cool conditions and not sweating very much, then fuel replacement is likely to be a greater priority than rapid fluid replacement. Under these circumstances, glycogen depletion is more likely than dehydration to cause early fatigue. Carbohydrate (energy) drinks, based on glucose polymers may be a better choice because they can provide more fuel than fluid replacers as well as reasonable amounts of fluid. However, some people find that carbohydrate drinks can cause stomach discomfort and that isotonic or hypotonic drinks do an equally good job.
The key is to experiment with different drinks in training to see what suits you best. Make your own, they are better for you and a lot cheaper!
Hypotonic drink #1

  • 20-40g sucrose
  • 1 Ltr warm water
  • 1-1.5g salt
  • Sugar-free/low calorie
  • squash for flavouring
  • (optional)

Hypotonic drink #2

  • 100ml fruit squash
  • 900ml water
  • 1-1.5g salt
  • Hypotonic drink#3
  • 250ml fruit juice
  • 750ml water
  • 1-1.5g salt

Isotonic drink#1

  • 40-80g sucrose
  • 1Ltr warm water
  • Sugar-free/low calorie
  • squash for flavouring (optional)

Isotonic drink#2

  • 200ml fruit squash
  • 800ml water
  • 1-1.5g salt

Isotonic drink #3

  • 500ml fruit juice
  • 500ml water
  • 1-1.5g salt

When making your own try to go for natural products where possible and use mineral water.
And remember most important, thirst is NOT an indicator of your hydration levels!
Sourced mainly from The Complete guide to Sports Nutrition, Anita Bean 1996

No Comments

Post A Comment