[Jesse Rich]

Hey Brian,

Jesse Rich here, a coach and nutritionist for Evoke Endurance. Thanks for your question! Seeing that just 2% body weight lost in sweat can impair performance, hydration is critical to perform at your best. Looks like you’ve already done a sweat test more or less. I didn’t see super specific times though (i.e. 2 pounds lost per hour), getting more specific there could help you quite a bit. To do that, do what you likely did before which is to weight yourself in the morning on an empty stomach and naked, then go on a run for one hour in the temperature you think would most mimic your race, then towel yourself off of sweat and weigh again naked. You want to replace 100% of water lost.

When it comes to electrolytes, it is impossible to be as precise without a test. I recommend levelen.com. You can get your test there for $120. You might as well just hold off on the sweat rate test if you’re going to do this test because that’s part of it too. You’re right though in that 500mg of sodium is a pretty safe minimum for almost everyone, but it can be up to 1,000mg or more depending on the person. Getting tested is well worth the investment to not have to guess and hope for the best in my opinion. It might be tight to get it done before the race, but at least you can have the water dialed. By the way, you have to train to drink that much too. If you just drink one 500ml flask per hour in training for example, don’t expect your stomach to tolerate one liter per hour unless you’ve done it several times hour after hour in training.

I hope this helps! If you’d like me to review your test if you get it or have a consultation with me, feel free to email me at jesse@evokeendurance.com. Good luck!