Heat acclimation improved time-trial performance by 6% in cool and by 8% in hot conditions. Heat acclimation increased power output at lactate threshold by 5% in cool and by 5% in hot conditions -Heat acclimation improves exercise performance
If you are as old as I am, the name Benji Durden may ring a bell. Durden put up an impressive string of 25 sub 2 hr 20 marathons, including a sub 2:10. He even made the Olympic Marathon team by finishing 2nd in the U.S. trials- unfortunately he never got to run because that was in 1980- year of the boycott.
I clearly recall one aspect of Durden's training that stood out more than the rest- "Always looking for a better approach, Durden began running in several layers of sweatsuits even in the Georgia heat" Now, after all these years, science has finally valided his theory that heat training made you a better runner in all temperatures.
Back to the study. According to Peak Performance at runnersworld.com, subjects exposed to heat acclimatization exercised for 90 minutes per day at 50% VO2 in 100 degrees F- a slow run in very hot conditions for 10 days.
How ironic that I stumbled on this information now- less than 4 weeks away from a sure to be warm weather half marathon in Cambodia. It's cold here now, so I've been doing a few short workouts long enough to make me sweat(indoor treadmill and cycling). I've even been in the sauna twice in the last few days.
After reading this, I'll continue some, but not all, of my workouts indoors- and I'll add an extra layer or two to make sure I work up a good sweat.