It’s no sweat to stay hydrated ~ but how do I determine my sweat ratio?
 
Our bodies (as adults) are primarily made of 60% H2O.

  • According to H.H.Mitchell, Journal of Biological Chemistry 158:
  • Brain and Heart are composed of 73% water
  • Lungs, 83%
  • Skin, 64%
  • Muscles and kidneys, 79%
  • Bones, 31%.

As we know, when we train sweat is inevitable, (even after our workouts, you may have discovered you’re still toweling off from profusion).  The amount of sweat depends on several elements, such as the intensity level, weather and individual temperatures, which included your sweat rate.

Here’s an illustration of the amount of fluid lost per hour of physical activity based on Low, Moderate and High sweat rates when physically exerting your intensity level of workouts correlating with outside temperatures.

If the temperature is:

  • 40 degrees then your sweat rate (ounces / hour)
  • Low = 12
  • Medium = 17
  • High = 31
  • 55 degrees then your sweat rate (ounces / hour)
  • Low = 15
  • Medium = 22
  • High = 35
  • 70 degrees then your sweat rate (ounces / hour)
  • Low = 22
  • Medium = 27
  • High = 75
  • 90 degrees then your sweat rate (ounces / hour)
  • Low = 31
  • Medium = 37
  • High = 75

Before every long or intensity training run, make it a standard practice to weigh yourself before and after your intensity training day runs. Calculate that difference, for example: if you lose 2 pounds (equivalent to 32 ounces) during your two-hour run, then you’d be considered to have a moderate sweat rate (based on your scale).

Please note, you can easily exceed the maximum rate your body can absorb fluid, which is 34-36 ounces per hour, meaning, you may not be able to consume as much fluid intake as you are using, (this is natural so don’t be alarmed) 🙂

Runners tend to consume enough fluids to replace 70% of the fluids lost through sweating when drinking by thirst, so rule of thumb, drink enough fluids to match 70% of anticipated sweat losses during each workout.