Sweat Equity
It was hot a Coeur d’Alene this year, and more hot races are bound to occur in the future—are you prepared?
How Knowing your Sodium Losses can Improve your Energy Budget
Races heat up more and more each summer, with several endurance events over the past decade seeing triple-digit temperatures on race day. Dehydration, an eternal issue for endurance athletes, has intensified along with the rise in temperature, shrinking your margin for error during competition and training. Today we’re going to talk about two ways to improve your chances to avoid the dreaded forced slowdown that comes with dehydration, lack of electrolytes, and too much core temperature.
We’re stoked on this right now because the two owners of CBCG headed to Endurance PDX to get tested by Jacob Rathe, recovering professional road cyclist and perspiration specialist. Jacob is the local Precision Hydration sweat tester, and he clued Chris and Molly in to their individual sodium loss rates. If this sounds interesting, look for a future group sweat test purchase here in Portland.
What’s the Problem?
When you exercise, your core temperature rises. Your body, ever aiming to maintain its homeostasis (your physical status quo), responds by sweating. Sweat should bead on the surface of your skin, evaporating and slightly cooling the blood just under your skin. That blood returns to your core at a lower temperature, keeping your internal heat in check (if we didn’t have this mechanism, we would overheat in the same way a car with an empty coolant reservoir does; in a human context this is called heat stroke and it can kill you).
But the problem is that as you sweat, you dehydrate, losing water and electrolytes in the process. If we stick with the car analogy (why always the car analogies?), it would be as if you lost a substantial amount of coolant every time you drove anywhere. If you didn’t replace the coolant every trip or two, we’d be back to the problem we cited above. Sadly, we haven’t figured out a way to keep our human coolant onboard permanently yet, so we need to replace it constantly. This replacing is called...hydrating, or just drinking.
We’ve known for ages that reducing fluid loss during competition maintains performance, aiming for keeping our water losses below 2% of body weight during events, but until recently we’ve only know that we should replace our lost electrolytes without having a number to aim for. That technology has arrived outside of high performance centers, and it should be the next piece of knowledge you add to your racing and training library.
Electrolytes—and in particular sodium—play a huge role in regulating endurance performance. From cramping to nervous system maintenance to hydration assistance, they help fix many issues athletes experience on the race course. But what if you could stay ahead of your electrolyte losses, knowing what you will lose and replacing them proactively? That’s the information a Precision Hydration’s sweat test provides you: your exact sodium loss rate per liter of sweat, so you can write a salt-perfect race plan for your next event, regardless of the temperature.
Athlete #1
Athlete #2
Everyone is Different
The biggest advantage of sweat testing is that it is specific to you. At Campfire, we write race plans that will work for 90-95% of athletes, and we do that by overestimating your sweat losses and aiming for more salt intake than you probably need. This approach works, if crudely so, and a better approach can get you the few extra percentage points you need, whether your goal is qualifying for Kona or simply finishing your next event. Above you’ll see two very different results from two athletes, which will result in two very different plans. Athlete #1 is a “low salt sweater,” losing only about 600mg of sodium per each liter of fluid they lose. Athlete #2 loses almost twice that amount! Prescribing the same electrolyte replacement strategy for both of these athletes will result in a “fine” outcome, but you don’t come to us for “fine,” do you?
Sodium Losses are Static, but Fluid Losses Fluctuate
The sodium content of your sweat is largely genetic, and won’t go up or down much at all. Your fluid losses, however, will change due to the conditions around your, your level of fitness, your training, and your acclimation work. In other words, the fluid losses per hour can change quite a bit! As you approach your key races of the season, lifting your sweat rate should be one of your goals. That may seem counter-intuitive (more sweat = more fluid loss = more dehydration, right?), but remember that sweating is your body’s cooling mechanism. If you sweat more, you’ll cool more. We just need to know how much you’ll lose in a range of circumstances. So it’s time for another test, this one free and that you can accomplish on your own: a sweat rate rest. You’ll simply weigh yourself before a hard workout in conditions similar to your goal event, weigh yourself after, and then subtract the fluid that you drank during the workout. The end result will look like this:
Athlete B’s Sweat Loss Calculator
Athlete B loses about 1.1 liters of fluid per hour. If we go back to Athlete B’s sodium loss per liter, we can see that they lose 1262mg of sodium each hour! Generally an athlete can replace about 70-75% of that sodium loss effectively, so this athlete needs to consume at least 1-1.5 liters (that’s 32-48 fluid oz. for you Imperial types) of fluid, making sure that they get in ~900mg of sodium per hour. Let’s say that this athlete will aim for 1.25-1.5 standard sports bottles per hour, which will get them 32-36 fluid oz or 1-1.125 liters. If their bottles have 7-800mg of sodium in each of them, they’ll be replacing their sodium needs. What’s 7-800mg of sodium in real-world sports drink products?
3 scoops PowerBar Isoactive
2 scoops Skratch Labs Hydration Mix
3 tbsp. Gatorade Endurance (roughly 3 heaping scoops)
3 scoops Clif Bar Hydration
1 package Precision Hydration 1500
We can’t really imagine adding three scoops of PowerBar, Gatorade Endurance, or Clif Hydration to each of our bottles, so for this athlete we would suggest going with two scoops and then a salt tablet that has an additional 2-300mg of sodium to get them where they need to be.
Let’s imagine, now, that Athlete A loses the same 1.1 liters per hour. At 635mg lost per liter, they only lose 700mg of sodium per hour! This athlete needs far less in their bottles as they compete or train. They still need to get in 1.25-1.5 bottles per hour (assuming the sweat rate is the same, which we’re assuming to just keep math, like, simpler), but they’ll only need around 500mg per bottle. That’s:
2 scoops PowerBar Isoactive
1 1/3 scoop Skratch Labs
2 tbsp. Gatorade Endurance
2 scoops Clif Bar Hydration
1 package Precision Hydration 1000
At hot, windy races such as Galveston 70.3, getting your hydration right means success or failure
The Plan Writes Itself
Now that you know your sweat rate, and how much sodium you lose per liter of sweat lost, and you know you can replace about 70% of your sodium, your hydration plan writes itself. Your goal is to avoid losing more than 2% of your bodyweight, as losses more than that are correlated with less-than-ideal performances. Don’t forget about carbohydrates in your fluid, though! We are living in a carb-phobic period, and we can’t tell you the number of athletes who tell us “we’ll just put this non-caloric effervescent sodium product in our bottles.” NO! First of all, carbohydrates improve absorption of fluid, so you’re already working against the beautiful replacement strategy we just worked out. Second, you’re an endurance athlete, for god’s sake! You run on carbohydrates. Skimping on carbohydrates during your workouts will simply rob your workout of quality.
CONCLUSION
Sodium content testing, up until recently, remained out of reach for everyday athletes, which is a shame, because your race shouldn’t be compromised by the conditions around you. Get sodium-loss tested, work out your sweat rate, and prepare to be impressed by how much better you feel in training and during racing next season!