“Know Your Sweat Rate”

While making the transition from sub-elite to elite marathoner, one of the most useful pieces of data I learned to track was my sweat rate.  Just as it sounds, sweat rate is the amount of water weight one loses during exercise.  This number is very important to know, as hydration affects performance, recovery, and general wellness. 

During endurance events, a rule of thumb is to drink enough fluids such that only 1-2% of body weight is ultimately lost via sweat.  If you gain weight from fluid consumption, you run the risk of hyponatremia, a condition where you over-hydrate, thus causing sodium levels to dip too low.  Likewise, losing too much weight can severely limit your performance due to dehydration. 

To calculate your sweat rate only requires access to a bathroom scale.  Weigh yourself immediately before heading out the door for a run, and immediately afterwards, and use the following equation:

[(pre run weight- post run weight)16oz ] + oz cunsumed during run}/ hours spent exercising

For instance, if I ran for an hour, during which time I drank 5 oz of water, weighed 150 lbs before the run, and 148 lbs after, my sweat rate would be 37 oz/hr.  Thus, during a 4:00:00 marathon, I could expect to lose over 9 lbs without proper hydration, which certainly would result in a trip to the medical tent!  Instead, a more realistic goal would be to lose only 3-4 lbs during the race.  To do so, one should aim to intake ~20 oz of liquids per hour during an event.

But, what do you do for a normal training run, when you don’t have thousands of volunteers to hand out convenient, pre-filled water cups?  A popular option is a hydration system, which is available in many forms, including hand-held, belt, and arm-band models. 

A running hydration system allows runners to train anywhere without worry of planning routes near water fountains, or having the time-consuming task of pre-placing water bottles around a course.  When choosing the best hydration system for runners,  there are several important factors to consider.  Would you prefer a hands free option?  Does the sound (or feeling) of sloshing water bother you?  How many bottles will you need? 

An option  is the Hydrosleeve® (http://www.hydrosleeve.com/), which is a unique armband device that fits on your bicep.  The Hydrosleeve ®is ergonomically designed for easy fluid intake while running.  One of the best features is that the system is slosh-free.

Ultimately, knowing my own personal sweat rate and drinking towards that number while racing and training made a huge difference for me in reaching my goals.  The addition of a hydration system to my training routine was definitely a game changer!

#sweatrate  #hydration  #hydrosleeve  #hydrationsystemforrunners