Sweat rate testing for athletes

Knowing how much your body sweats and how much salt you lose in that sweat is vital information for every athlete exercising continuously for longer than 30 minutes. When it comes to performing in the heat for long periods such as in Ironman Triathlon events, ultra distance runs or cycles then understanding what your body loses in sweat is vital to your final result. If you have problems successfully completing long distance events then I recommend that you  consider sweat testing as the information you gain could lead to a change in what types of drinks and drinking strategies you use. This should then lead to more successful performances in the future.

Sweat volume testing - part 1 of the equation.

DrDobbin can provide estimates of your sweat rate and appropriate advice for drinking strategies during your key races of the season.

The procedure used is as follows:

  • The duration of a test is recorded in minutes. It will be at least 90 minutes**. Normally you will want weather conditions to be similar to those in your target race for the season.
  • Your weight is accurately recorded before and after the session by weighing with as little on as possible. This avoids difference in weight between wet and dry clothes. Accuracy should be to 10ths of a kilo.
  • You record how much drink out on the road in millilitres. Know your bottle sizes 750ml=750 grams etc.
  • You record any food/gels/salt tabs that you consume giving the weight in grams if possible. If not just describe it, e.g. 1 small banana.
  • You record the number of toilet stops you have. 
  • You record your effort level - Easy, medium or hard*** or an average heart rate.
  • We also use your age and gender and record the humidity and temperature on the day of your test.

**Sweat rate tests are available for cyclist or runners. The duration of runs are likely to be less than the duration of rides and are likely to produce higher sweat rates.

***Easy is when you can hold a conversation throughout. Medium is when conversation would be sporadic, hard would be when it is difficult to talk at all.

An estimate of your sweat rate during the exercise is the provided to you.

Sweat rates vary with temperature, humidity, a person's health, hydration levels and a number of other factors. DrDobbin takes into account not just the water you drink but using the other factors recorded can estimate, levels of salts and carbohydrate reserves. This will enable DrDobbin to provide a short piece of advice on hydration strategy for future training and competition as well as your estimated sweat rate.

Sweat salt testing - part 2 of the equation.

The amount of salt in your sweat is genetically determined and varies little with heat acclimation or sweat rate. If your sweat is salty you will want to use more sallty sports drinks to ensure a deficit does not build up. DrDobbin nutrition can provide an accurate measure of how salty your sweat is via the guys at Precision Nutrition. They use state of the art testing equipment developed from test equipment used in the diagnosis of cystic fibrosis.

In short you get your sweat volumes tested to work out how much and how often you should be drinking during training and racing. You get your sweat salt tested to find out what strength of sports drink you should be using. This information is vital if you want to reduce the possibility of failure due to water or salt imbalance during races.