I love the feeling of a good sweat, don’t you? I mean when you have the intention of sweating, not when you are commuting on a blistering humid summer day and are sweating on the train platform in your work clothes thinking, why did I even shower?



Earlier this year I took a tumble while skiing and needed ACL reconstruction surgery and a meniscal repair. So, for a solid 4 months I wasn’t really capable of doing anything to work up a good solid sweat. Now that I’m back at it and the thermostat is starting to soar, it’s a good time to take a deeper dive into the sweat pool.


When you sweat, in addition to losing water, you are also losing electrolytes and minerals.  The most abundant electrolyte lost and most important when talking hydration is sodium.


I will often talk to athletes who will tell me that they do a great job with their hydration because they drink “a ton of water”.  I’m all for adequate water intake, however, that’s not the whole picture.  Depending on how much you are sweating and how much sodium you are losing in that sweat, drinking water alone (in addition to a low sodium diet) might not be the best solution for your daily hydration needs.


For training athletes, there’s a lot to consider with daily needs, training needs, recovery needs, and racing needs, especially if you race in a hot environment. One of the worst things you can do for your performance on race day is to show up to the starting line dehydrated.  There’s no doubt that everyone will finish a race with some degree of dehydration, it’s inevitable, but how you start the race can mean a leg up on your competition.


Getting that leg up is not as easy as just making sure you drink enough in the week leading up to the race. It starts way before then, because let me be clear, chronic dehydration will impact your workout quality and recoverability, not to mention making it harder to be euhydrated come race day.


The second chance for a leg up on competition is your in-race hydration strategy. Again, creating this plan and practicing it should start long before race week.  


These situations are a sign that you need to work on your hydration strategy:

  • struggle in workouts in warm or hot weather
  • feel very lethargic in the heat
  • have to shorten or skip workouts because of the heat
  • notice a large and consistent spike in your heart rate in the heat
  • take extra time to recover from workouts in the heat



There are two opposing views out there for what an appropriate hydration strategy should be, either drink early and often or drink to thirst. It’s no surprise to me that folks in both camps have steadfast belief in their view. Having tested many athletes sweat sodium levels and seeing the large variation in hydration needs from one person to the next, I agree that each strategy could work for certain people, but that’s all a guessing game.


The only real way to know your best strategy is to take a sweat test. The amount of sodium in your sweat is largely genetic and will not change much over your lifetime. When you have this data your hydration strategy is based on your sodium losses.  And you know what they say…”Knowing is half the battle!”


There are two options for sweat testing that I recommend: take this online sweat test as a first step to dialing in your plan or book an appointment to have an advanced sweat test. The advanced test will give you the amount of sodium you lose in your sweat and you get a personalized hydration strategy to match.


I could go on sharing stories of the athletes whose lives, training, and performance have changed because of this data, but the best way to know is to experience it yourself.