Marathon Training in Heat

[Jeff Linger]

After reading some articles online about training for a marathon during the summer when heat and humidity levels are high I've discovered a number of tips. I'd like to list them for anyone who's interested and then follow it up with a few questions.

Hydration: Drink 4-6 ounces of water every 15-20 minutes during the run. Drink 16 ounces of water post-run for every 1 pound of water loss (weigh yourself before and after the run). Golden colored urine is an indication of dehydration. Continue to drink throughout the day until your urine is a pale yellow. Regularly drink electrolyte replacement drinks and eat salty foods to maintain electrolyte balance.

Select cooler times of the day to run (morning and evening), but understand that humidity is just as influential as temperature and that humidity tends to be higher in the morning than in the evening.

Wipe sweat from your body regularly during your runs to allow your body to cool itself more efficiently.

Take walking breaks throughout the run to allow your body temperature and heart rate to come down. This will allow you to maintain your goal pace during the running sections instead of your body's core temperature continually rising resulting in a continually decreasing pace.

On quality speed days decrease the mileage to focus on maintaining pace rather than distance. On quality long days slow the pace down to allow you to complete the desired distance.


I'm mostly concerned with keeping a balance between getting in the necessary types of quality workouts conducive to optimal marathon performance without putting the body in a position where long-term fatigue begins to set in that takes weeks to months to recover from. Many times people intentionally heat training indicate that the long term effect of such training is overall fatigue that results in poor performance for an extended period of time after the heat training is finished. What tips do some of the seasoned heat training runners have for us? How do people in the southern states maintain optimal marathon training while avoiding negative long-term effects of fatigue? Let me set an example (all times are based on non-heat-influenced race conditions): Let us assume that a runner is targetting a 3:10:00 marathon. For argument sake we'll use McMillans conversion chart that gives us the following: 10k pace = 6:30s; 15k pace = 6:45s; 1/2 M pace = 6:53s. If we assume that most tempo runs should be done at a pace that a runner can maintain for about 60 minutes we're probably looking at a tempo run in the 6:45-6:50 range. Lets then put this runner in conditions where most of their runs occur in 75+ degree temps and 70%+ humidity.  Under these conditions, based on a heat index chart, this runner will be running in conditions whereby the "apparent temperature (what it feels like)" is a minimum of 78 degrees on the coolest of days. Under these conditions our runner in question is hard pressed to maintain a 7:30/mile pace for their 10 miler on most days. What changes to their training do they make? Do you base your runs on effort? Will that 10 mile tempo run of 7:30/mile in those conditions yield the same results that a 6:45/mile tempo run would under cooler conditions? 

[Sasha Pachev]

My thoughts:

If training in cooler conditions is not an option, then just jog for as long as you have time for. If you are blessed with a cooler day, run fast. Do your speed during winter. It is not necessary, and is perhaps counterproductive to do speed year round. You need breaks anyway. Here in Utah we take a break during the winter - you cannot run fast on icy roads. In a warmer climate you do it during the summer instead.

If you are racing in a hot climate, the best thing you can do to prepare is have a solid aerobic base and be in good overall health. What saves your bacon is high blood volume that can be sacrificed to cool the body off. So you need to have more of that volume than you need for running. Then you can run near PR in the heat.

Speed training works primarily on muscle power and neural drive. High neural drive will not save you in the heat to begin with, and if you train in the heat, you will not be able to push its limits anyway because you cannot run fast enough. Not sure about glycogen storage development, but my feeling is something will break when trying to work on it in the heat. It would be very hard to run the right pace for long enough to reach proper levels of glycogen depletion. The heat will stop you before you will get there. If not that, then the recovery will not happen as well due to the heat stroke effect.

[Steve P]

For my last marathon, I was living in Phoenix and was trying to prepare for the marathon during the summer. So I did most of my workouts on the treadmill (rather than run in 80-115 degree weather). Probably not the best option, but it may work if you need it to.

[Sasha Pachev]

Worked well for Christine Clark in 2000 - she won the Trials in warm weather. She did have a relatively weak field, though. She would not have won against Deena Kastor or Kara Goucher. Ingrid Kristiansen also trained on a treadmill a lot. Interestingly, she was very much a time trial runner - any time she met her match in a race, she lost. Fortunately for her, at that time she did not meet her match very often.

However, I cannot think of any treadmill heroes in men's running history. Perhaps because men's marathoning is more competitive, you pay even for small gaps in your training, and treadmill training is a gap that cannot be compensated for by other strengths at that level.

[Steve P]

Interesting. I didn't know that she had won the trials. Pretty cool.

Another thing occurs to me about training in the heat...you might think about what the temperature range will be on race day. If you do a ton of training in heat but then you do a morning marathon in a cooler climate, it might not hurt you, but your training and race will be in different conditions and could throw you off. Just a thought. If this is the case, then training outside very early morning or running on a treadmill in a cool room could help simulate the conditions.