Favorite Workout: Sauna Sessions

by GRP Runner Elena Horton

As we transition from winter into spring, I find myself feeling overheated while running if it’s anywhere above freezing temperatures. It’s time to start readjusting to the heat, especially if you’re training for some late spring and early summer racing. Luckily, my favorite workout for this is more relaxing than anything – sauna time! One big caveat for this heat training is to not overstress your body. Be sure that you are cleared for sauna usage by a doctor and do not stay in longer if you are overly uncomfortable. 

Like anything in training, building up some heat tolerance in the sauna is one of those extra little things that can add up. No, it’s not going to replace your weekly mileage or benefits from hitting your workouts, but it might help you to stay cooler and steady if given a hot race day (a sadly more common experience each year). Heat certainly impacts people differently, but, for marathoners, studies have shown that for every 1.8℉ over 59℉, pace slows by ~4 seconds per mile. That adds up, as it implies that a marathon time on a “perfect” 70℉ and sunny day could be ~10-15 minutes slower than your potential. 

So how should you go about heat adaptation training in the sauna? There’s no perfect science, but there are some best practices to optimize your response. First, aim for 2-3 sauna sessions of about 20-30 minutes each per week, ideally right after a training run. But it’s also ok if you go later in the day. While it may sound counterintuitive, try not to rehydrate fully while in the sauna or immediately after. Rather, rehydrate slowly over the next hour and avoid taking a cold shower immediately after exiting. This approach is aimed at catalyzing your body to increase its blood plasma volume naturally, which is a primary driver in your body’s ability to cool itself. Additionally, recent studies are suggesting that this in turn could increase the amount of red blood cells in your body, which is a big performance booster (more blood to carry oxygen around to your tiring muscles!). All of this makes heat an important training stimulus to pay attention to. 

If you don’t have access to a sauna, don’t fret! As the temperatures start rising this spring, you can experiment with running during the heat of the day. It can be helpful to mentally shift this in your brain from poor running conditions to a helpful training exercise! Keep your pace easy and unlike the controlled sauna stimulus, be sure to stay fully hydrated while running in the heat. For both sauna sessions and heat running, it’s best to include these in your training starting 3-4 weeks before your race. As always, listen to your body and, as hard as it can be for athletes, don’t push too far into being uncomfortable. A little heat can go a long way!