Nutrition when it's HOT HOT HOT
Looking for some insight into how to adjust my nutrition for the blazing hot temps predicted for Coeur d'Alene. My nutrition plan has been practiced and proved successful, but I haven't ridden in temps about upper 70s yet this year since Chicago hasn't gotten the memo it is spring/summer. My current nutrition plan is 1.25 bottles/hr gatorade (those are 24 oz make your own bottles, need to recalculate because I think race day is 20 oz bottles?) plus 1/2 a bar, for 320 calories an hour. So if it is really going to be 98 degrees, I'm going to need to drink A LOT more. There is definitely a finite amount of gatorade I can handle and I've had to work hard to be able to handle the 1.25 bottles an hour. If I drank more I think my stomach may revolt and then my calories would also be a lot higher. Do I add water and just take a lot of salt?
Comments
I think the main difference is in electrolyte balance. Particularly sodium. Living in Miami, we deal with this for more of the year.
There are some pretty predictable responses that you can expect from your body as you become acclimatized. For the same level of exercise:
- Your sweat rate increases
- The salt concentration in your sweat decreases
- Your heart rate will stabilize and lower
- RPE will become less
- Your plasma volume will increase
It takes 10 days to two weeks to acclimatize, so unless you have that amount of time in the heat, you can expect to have issues with each of the points above during a hot race. Your body will trick you too - your need for fluids is dramatically higher but you will not feel thirsty.
Here are some things that I do:
- I increase my sodium. I start pre-race with some sodium loading the day before and pre race. On the bike, I take an extra SaltStick each hour.
- I force the fluids. I try to hit two bottles each hour. I cannot do that on Sports drink because it is too many calories and I start feeling sick. So I supplement with water. I force myself to drink each time the lap counter goes off (for me each 5 miles) whether I think I need to or not.
- I do not take any solid foods during the race. Because blood plasma levels are lower then they need to be for the heat, and so much of your blood is diverted near your skin to cool you, there is less left over to digest solid foods. I had a really bad experience in Los Cabos where I was eating solids, but bonked because they weren't digesting. Now it is all liquid.
- I am not able to handle as many calories in the heat as I can on a cool day. Especially while running. This makes it more important to get myself fueled at the end of the bike and at the first few aid stations on the run. If it is hot - it will become harder and harder to take the calories as the run progresses.
In addition to diet, there are a few other things to think about.
- I really focus on HR more than normal. During the run, I run at my target HR and let the pace go where it wants to go (always slower in the heat). I've found that I can trust what my HR is telling me more than I can trust some formula that predicts what pace I "should" be able to achieve in the heat.
- Watch for your HR to decrease. If you are going along at a level or gradually increasing HR on either the bike or the run, and suddenly you notice that HR is starting to decrease, this is a big warning sign that you are running out of calories. When I've seen this, normally on the back half of the run, it is time for me to act quickly with a gel or something to raise blood sugar level. This happened at Raleigh this year. After a gel, my HR started to increase back to normal rates and my pace followed.
- Have a cooling strategy. for me, this includes:
- Arm coolers. I wear them on the bike and the run and they help tremendously
- Water on your head and jersey during the bike and run (careful not to wash the sweat into your eyes)
- The plastic bag trick (keep the Zip Loc you have T2 stuff in and fill it with ice at each aid station). I put the bag on my head and used visor to hold it in place. So much blood goes through your head that this really cooled me. Anna stuffed hers in her sports bra. Whatever works for you - keeping the ice in the bag is much more effective than just taking a cup. You can carry more ice and when the ice melts you can pour the cold water on yourself.
Unless you are arriving early, there isn't much you can do to acclimatize. It takes time. You can do your workouts in the hot part of the day to get your sweat rate up, but make certain to hydrate hydrate hydrate the whole time you are there leading up to the race.
Any food I do take is generally in small bites, more evenly distributed over time (ex, every 15 minutes), to not force a lot of blood to my stomach instead of the cooling/sweating process.
Of course, this is all practiced since I live in a, usually, hotter environment than most.
But I'd also say each aid station to get a hand-up bottle of water, whether you need it or not, and drink a mouthful and pour the rest over your head, shoulders and back, and arm coolers if you have them.
Please note that electrolytes are more than just sodium! There's potassium, magnesium and calcium too! I drink double-dosed Nuun for days leading up to hot and humid events; a "pre-load" if you will. Knock on wood, never had cramp issues.
Rachel, without knowing all your facts, may I be so bold as to say, you will definitely need to drink more than 1.25 bottles an hour if the race is going to be in the 90s. Add more fluids. Especially in the beginning of the bike. I do power gels or cliff blocks as my food. All other calories come from sports drink. When you say your stomach may revolt. Are you speaking to your dislike of the taste of Gatorade or is it something else? I don't think you can just take extra salt, you need the fluid too. So that could be some water if you really just can't handle the sports drink, but I would only take that water with something that has sodium in it. Otherwise the water will just sit in your stomach.
I've ridden a few hot races and done several big training days under crazy hot Virginia temps. Just did Challenge Williamsburg 70.3 where it was well into the 90s and crazy humid.
Day before, I'm pre loading with normal Gatorade. drinking some water but mostly sports drink.
Day of the race I'm drinking Gatorade Pro or in the past Perform.
On the beach, I'm sipping sports drink. Leave the bottle on the beach. Once I hit the bike I'm doing 40oz an hour of sports drink until I have to pee. That used to be two bottles of Perform. Now with the 24oz bottles of Gatorade things are a bit different. For Me I'm filling a 20oz Torhans and sipping from a straw so I can still count by 20ozs if that makes sense. Before I ditch the bottle at an aid station I'll take another swig of the remaining 4oz. For me, the fluid is my fuel. I don't care what it taste like or how cool or warm it is. I just drink it, cause I need it.
If I started the race with normal Gatorade I always put a NUN tab or some salt tab in there to plus up the electrolytes.
Once I have to pee I give myself some permission to back off the fluids but only by a little. So instead of 40 oz an hour its closer to 30. My last Ironman which was pretty warm, but not crazy, I didn't have to pee until mile 70 of the bike. I was drinking to save my race up until mile 70 of that race. But listen to your body.
If I do drink some water I do it only with a salt tab or gel.
and agree with the Zip lock bag with your run stuff. Fill it with ice.
Good Luck...
For heat acclimatization, you should do a little reading on sauna protocols. After exercising, you sit in saunas or hot tubs to build plasma volume. The idea is to start out slowly, maybe 5 minutes and work your way up to 30+ minutes over a two or more week time frame