Racing In The Heat – Part II

Written by Jesse. Posted in Coaching Thoughts

This post is a follow-on to my last post and addresses those things you can do on race day to mitigate the potential detriment heat can have on your race day speed potential.

1) Drink — As I said in my last post, drink enough to pee at least twice in IM and at least once in half IM. The best way to do this is always through a front loaded drinking schedule that has you drink more early on during the bike with a little less focus on catching the guy/girl that’s going too fast in front of you. Once you pee, you know how you are doing with hydration and should continue as required. Conversely, if you get behind, it’s very hard to catch back up late in the bike leg, and typically has you start the run bloated. Peeing during the bike leg is a great barometer of how well you are doing with your hydration and should be the number #1 priority before really starting to pick up the pace.

2) Make sure you have a heat adjusted pacing plan — there are many things you can do that lead to “stomach shutdown” during your triathlons. One of the most common is stress, whether it is from heat, or from intensity (or both!). Based on that, in a hot race you are always better off heading out very conservatively so you stay cool and give yourself a chance at being able to get down the fueling and fluid discussed in number 1. Once you pee, you can start to pick the pace up and slightly descend or even split the ride. It never helps to go out harder than you plan to average, add a bunch of heat and intensity related stress, and have your stomach shut off. No fuel in, means no forward motion, and a bad day.

3) Wear clothes that help you — although heat typically isn’t a big problem on the bike due to the huge amount of cooling wind that you get, it still makes sense (particularly for those sensitive to heat), to use a helmet that’s well vented. As long as you are removing heat faster than you are adding it (or at least equal), everything will be just fine. I call this balance “heat equilibrium” pace. You can really play on both sides of this balance by doing things to remove heat (ice, water, vented helmet, etc), and things to add less heat (light colored clothing, reasonable pacing). Going faster at any point during the day than you plan to average, adds heat quickly and therefore runs the risk of surpassing that heat equilibrium. Once this happens, the additional stress of overheating, many times leads to that dreaded stomach shut down…..the beginning of the end. If you do start to get an upset stomach, and you know your fueling plan is solid (adequate sodium, fluid, and carbohydrate) it’s likely due to exceeding that heat equilibrium. The first priority is to get back to a temperature that’s acceptable to your system so you can digest food. You can’t step the pace back to your heat equilibrium pace (a pace where you are adding heat as fast as you are removing it), since this will maintain your current temperature which is obviously too hot! Instead, you need to consciously slow down by a bunch (maybe 30-45 seconds per mile on the run, and 20 watts on the bike), to create a negative heat balance where you are removing heat faster than creating it. This will get you back to normal temperature, let your stomach settle, and then you can pick it back up to heat equilibrium pace. This takes big discipline, but at the end of the day, it can save a nasty situation before it really gets bad. Most people continue to push on the pace, continue to add heat, and the pace slowly grinds itself down due to the lack of digestion (not at the choice of the athlete). This typically results in a long walk before anything gets better. At best, the walk finally allows the core body temperature to drop a bit, food start to settle, and a good run for maybe the last 2-3 miles. Nip it in the bud before it gets there by following my recommendations above….have the discipline to slow down a bunch when it first hits and you will save yourself the long walk.


I know it’s the middle of winter, but keep these items in mind as the summer race season heats up.