Heat Training for Running High

Training for altitude at sea level is kind of like practicing kissing on an apple. You can approximate it, but it probably won’t get you 100-percent ready for the big dance.

At altitude, the body senses the reduced oxygen, causing an increase in breath rate. The heart beats more rapidly, cardiac-stroke output decreases and digestion is impaired. The physiology is immensely complicated (and we’re running out of words), so it can basically be summed up by thinking about the blood, like a vampire with a medical degree.

Inadequate oxygen being transported by red blood cells spurs increased oxygen-carrying capacity in the bloodstream. That’s why altitude-trained athletes often perform better at sea level, too. There are lots more relevant adaptations, like increased aerobic-enzyme concentration, pulmonary-artery pressure and capillary density, among others.

It’s hard to simulate a similar stress without altitude. That’s why some athletes sleep in altitude tents or do intermittent hypoxic training to prepare for mountain adventures. But one possible avenue to adaptations adjacent to those from altitude is heat training.

Heat-stress acclimation expands blood volume by 15-plus percent, and researchers are now looking at whether it spurs natural EPO production. Those adaptations could improve cardiac performance at altitude, or at least make the acclimation process proceed more rapidly. When I was starting out, I had a coach tell me that, “Heat is the poor man’s altitude.”

The simplest way to get the process started is with a dry sauna. Protocols vary, but athletes I coach have had success with 20 to 30 minutes in a dry sauna immediately after exercise, with no rehydration for 30 to 60 minutes after the sauna and exercise combination to optimize blood-volume stress. A recent Trail Runner article went over additional options using a hot tub, hot yoga or normal heat training.

And perhaps the most important thing is just to get really, really fit through good training. Altitude will impact performance of someone who is unacclimated no matter how much time they spend in a danky public sauna. If you’re going to be operating at 90 percent of your potential, raising your potential can lead to a pretty badass 90 percent. 

David Roche partners with runners of all abilities through his coaching service, Some Work, All Play. His book, The Happy Runner, is about moving toward unconditional self-acceptance in a running life, and it’s available now at Amazon.