I overheard this comment from a runner recently. He was bragging about how running in 100F+ (42c+) degrees was such a great workout. He went on to state that it’ll get him in shape faster.
On the surface it almost sounds feasible. Heat creates further stress on your body. You have to work harder (both subjectively and objectively) to do the same workouts.
I’ve known runners who even INCREASE the heat by wearing body suits, warm-up outfits and even worse – plastic type body outfits. This practice is something that many archaic neanderthal coaches in wrestling still advocate to this day! This is all in the name of getting in better shape (oh and losing weight in the case of the wrestlers).
Sorry to say we need to dispel this myth. It is more than well documented that heat – especially excessive heat…
1. slows you down
2. reduces the amount of work you can do
3. is downright dangerous
Fact: You will never race (or run typical track workouts i.e. 8×800) as fast in heat as you will in moderate temperatures.
Fact: Heat build up in your body ultimately reduces what a body can do.
Fact: Force yourself to run too far or too fast or assume you can push paces and distances similar to moderate temperatures and you can cause physical damage – up to and including death.
Running in heat is an unavoidable fact of life for many of us – especially those of us in the southwest. For five months our daily high temperatures will be over 100F degrees. Even in the evenings it remains in the 90s. We’ve even had overnight lows never go below 100F (though rare it happens). So, running in the heat is doable. But we should not confuse this with getting us in better shape or doing some miracle conditioning for us lucky ones.
The bottom line facts are:
You will run somewhat slower in the heat.
You will not run as far in the heat.
Therefore, your conditioning will suffer to some degree in the heat – NOT improve!
And these statements go double for anyone who is not already in good shape already – BEFORE – the heat commences.
What can you do?
Get acclimated to running in the heat by running regularly (not even everyday) in the warm part of the day. I don’t advocate just going out at three in the afternoon in 110F degrees. Let’s get real. But, running when its in the 90s in the early mornings or evenings and the occasional 100F degree run may be doable. By running in small doses in the heat you acclimate. You will handle the heat better.
Slow down your pace on your typical run. But still get out and run.
Go on shorter runs. Something is better than nothing.
Do some track workouts but modify what you do. Keep intervals shorter (200-400 for instance instead of mile repeats). Have longer rest intervals and drink fluids. By keeping some modest speed work in your repertoire you will retain much of your hard earned speed from the spring.
Now, I have not addressed the psychological impact of running in the heat. If you persist through the (modified) hot weather runs then naturally it should bolster your mental toughness. It builds character!
PS – a tidbit – living in hot climates does not automatically acclimate you to exercising in hot climates; neither does running indoors on a treadmill (though this is a nice option for many).
In the end, do not fool yourself into thinking that running in the heat gets you in better shape. That kind of thinking could kill you.