Sweat Rate Calculator

Fuel in, Sweat out

Fuel in, Sweat out

Summer has arrived and along with it, a rise in temperatures. Increasing temperatures increase your hydration rate during workouts.  Typically, we assume 20-30 ounces per hour is enough for most athletes, but when the temp rises, the need to increase hydration AND electrolyte intake also increases. But how much do we increase that number?  There are general guidelines suggesting 0.185 ounces per pound of body weight but this is just a “general” recommendation and as we know we are all very different. To properly predict how much fluid you need to replenish, you need to keep in mind factors like heat, humidity, metabolic rate, intensity of training, body core temperature, body surface area, etc…That’s a lot of science and calculations. It could get expensive testing all this in a laboratory not to mention that it all changes as the environment changes; and you change too(typically the fitter you are the higher your sweat rates). But there is a simplified approach which is also cost effective. Use a scale.  Yes, a simple scale like one you typically have in your bathroom.  Most of the weight you lose during your workouts is water weight.  So weigh yourself (dry) before and after your workout.  Note the environmental conditions to get familiar with how your body reacts to conditions. Then – and most important – know how much you drank during the workout and how many minutes the workout lasted. When these three variables (nevermind environment for just a minute here) are known, you then have the ability to create the equation for what your sweat rate is. We have a nice outline and equation below. But before that… When it comes to the consideratioin of environment, what we are looking for is standardization of the elements. We tyically ride through consistent blocks of weather as we prepare for – and during – the season: the winter cold, the spring rain, the summer heat. Each of these “zones” are relatively consistent. In that, your sweat rate will different in each, and so, it goes to say that when you learn what “zone” you’re in, you can adjust your hydration rate based on what you learn of your sweat rate. Now, for a very important note: One pound of water equals 15.4 ounces or 1 kilogram equals 1 liter of water. Now, experiment. Find out what your needs are and how good you are at managing your hydration by doing the pre-ride and post ride weigh-ins, then noting your consumption during the ride.  I suggest measuring for a week in similar environmental conditions to get a good guideline for yourself.  By the end of the week, you’ll know before you even get on the scale how well you did during your workout. Sweat Rate Calculator

A. Weight Pre exercise                                          ________lbs

B. Weight Post exercise                                        ________lbs

C. Change in Body weight (= A-B)                       ________lbs

D. Volume of fluid consumed                             ________oz

E. Sweat Loss (=(C*15.4)+D))                               ________oz

F. Exercise time                                                       ________min

G. Sweat Rate (=E/F )                                              ________oz/min

All measurements in ounces (oz) and pounds (lbs)  To convert to metric system:

Why is all this important?  Hydration is the number one reason for fatigue during exercise.  Even at 2% loss in hydration, you can expect a performance decrease.  Stay ahead of the curve and DRINK! Do note that your sweat rates will change with changing environments (ex. winter vs summer).  Also if you are just changing to a higher temperature environment, that your sweat rates should increase in 10-14 days as you acclimate to the warmer temperatures. If you would Tenac Championship Coaching  to calculate your sweat rate, simply contact at info@gotenac.com with the subject line: Sweat rate