Sunday, May 28, 2006

Heat acclimatization

Today's run in the late morning convinced me that I have a long way to go on heat acclimatization this year. Only 81*F heat index, but it still felt hotter and quite uncomfortable running in the full sun.

Exercise in the heat triggers these adaptations over a two-week period:
  • Lower core temperature at the onset of sweating
  • Increased heat loss via radiation & convection (skin blood flow)
  • Increased plasma volume
  • Decreased heart rate
  • Decreased core body temperature
  • Decreased skin temperature
  • Altered metabolic fuel utilization
  • Increased sympathetic nervous system outflow (efferent)
  • Increased oxygen consumption
  • Improved exercise economy
  • Adaptation to exercise in a cool environment
  • Adaptation to exercise in a hot environment
Lots of good detail on the process here.

But the take-home lesson for me today is: GET MOVING! And do it sensibly in the hotter time of the day if you're going to get your body adapted to the potentially scorching conditions at Eagleman in two weeks! And some sauna time wouldn't hurt, either. . . .

Note to self: Remember this fall that these adaptations can go away within 2 or 3 weeks too. You're going to need them at Ironman Florida in November, so remember to include some higher-temperature training and sauna time throughout the autumn!


Mojo said...

Uuggghhh, it's getting hotter than goat balls in NC now too. It's the humidity. You know it will be hot when you look at the window and it's hazy.

I never knew it took the body two weeks to adapt. I ran in the heat Saturday and today. Does doing chicken and goat chores count or does your heart rate need to be high?

Dawn - Pink Chick said...

Good list and good luck with it.