Tuesday, June 28, 2011

Tropical Heat and influence on the training of the runner

"I can understand a little of what you're going through there Roberto. The humidity and heat creaping up here in Osaka but thankfully not to the levels you have to put up with. Interested to hear what you do to keep running in those conditions, hydration etc etc"

I got this comment from Scott which in a sense touched an issue of common interest...
..how to train under a tropical-style heat ?

honestly speaking, most of the suggestions you can find in running magazines are pretty much obvious: run early in the morning, drink a lot, etc...

on the other extreme of the spectrum, there are all the dissertation about the role of the Central Governor in avoid overheating, etc, which are sometimes beyond my grasp...

now the question is how to do, when the minimum temperature in the day is at least 27-28C, high humidity and a long long summer ?

I personally found that running in heat poses 3 challenges:

1) Alteration of gait caused by running "slower"
Let's say that crawling around at 30"/km slower than the usual pace is anyway having an effect on the stride. The muscles get into their memory a shorter and less reactive stride.
I think that several months of that and then it can become difficult to regain the right muscolar-activation pattern 

2) Heart Rate Drift caused by heat
Once the body can not lose enough heat fast, the HR begins to rise even if the runner keeps a steady pace and the duration of the run is within his normal training.
Personally I found that with temperature around 28-29C and 80%rH, I can keep around 25-30' at easy pace or 15' at faster pace before my HR begins to rise (and rise a lot).
It is not uncommon that even if I am just running "easy", after 90 minutes my HR is in MP or HMP territory.
Even worse, while doing "faster" workout, the HR can go easily over 90% HRmax even the pace is kind of "moderate"

3) Day-by-day recovery
It is quite common in tropical weather to lose 2.0-2.5L of water per hour.
Run 2 hours and even if you drink 2-3 bottles during the run, you will end up losing 3Kg of sweat.
That means that rehydratation involves drinking at least 4 liters of fluids before the next workout. This also goes together with the loss of minerals, etc
Honestly after a long run I feel really bloated by all the water which I know I MUST drink...

Anyway first a piece of good news:
Heat acclimation gives big cycling performance improvements in cool conditions, study finds
"A recent study by human physiology researchers at the University of Oregon found that huge physiological gains could be achieved in trained cyclists by doing 90-minute easy rides in high heat for 10 days.
Before the testing, the researchers expected to find improvements in the hot-weather performance of Cat. 1 and 2 cyclists after a heat-acclimation program. But what surprised them was that the physiological improvement translated to cool-weather performance as well."
This is something that I always suspected ... because whenever I leave HK in Summer and step out from the plane in a cooler country, my running takes another dimension, almost feeling effortless...

So there is a good reason to grind through the summer, but how to make it easier:

These are only my personal thoughts and experiences:

1) try to run in "doubles".
I know is very difficult to do for an amateur runner, but running in doubles during summer could be hugely beneficial:
- it is much easier to reintegrate 2 times 1-1.5 Liter of water, than 3 Liters...
- because it is unavoidable to slow down after 30'-45', the runner can base the training on 2times x30'-40', keep an higher pace and maintain a more correct stride.

- even for a long run, probably a split into 1h+1h at decent speed is much better than crawling around for 2hours.
I know runners who pride themselves to keep going also during heat waves, even if they have to slow down a lot. But honestly I do not see the benefit to run at 5'30"/km for a runner whose "cold weather" easy speed is 1 minute/km faster..
For keeping a good stride and also mantain certain neuromuscolar patters,  I personally feel much better to run almost at my "normal" speed (let's say that 10"-15"/km slower is unavoidable), but stop when I can not keep the pace anymore...
I also do not feel anymore any issue with running 30' at good pace, stopping 5' for drinks and cool down and then start again..

2) fractional workouts
the concept is nothing different from point 1), but inside the single workout. 
No point to make "tempo runs" where the speed is too far from the target one or where you suffer a dramatic drop of pace after 20'...
much better to run at the "real" target speed, but in intervals.
So better 6-7x2km, than a 10k tempo run. The rest gives the time to drink properly and cool down the body a bit, so that every active interval is performed at the real target speed.
I am also applying this to longer runs: even for long runs, I split into many short intervals (maybe 10-15x2km) with time for drink and cool-down, or longer interval with longer rests (20' followed by 2' drink/cool-down), all performed at my "cold weather" speed or whereabouts.

3) day-by-day recovery
this is an area where I am really still in search for a better way.
- what to drink, what to eat ?
- how to recover quicker ?

for example, drinking only water makes difficult to reintegrate also the minerals, etc... but if you switch to sports drinks or fruit juices, then there is the problem of the too large caloric intake (a glass of juice is over 100-150Kcal).

Also the drinking pattern: drink a lot immediately after the workout  (not keeping into account anyway the limit of the effective absorption rate by the body), or drink a little but all over the day...

on top of that, I think that all the runners from S.E. Asia and similar climates suffer from the same situation where the fatigues increase day by day, and the heat is a kind of chronic illness which really affects the level of energy, even if in theory he/she drinks, eat and sleep enough.
There is a kind of cumulative effect on recovery of training in the heat, where it becomes impossible to fully restore from the day before.
I personally felt almost "on my knees" at the end of each summer, only waiting for the weather to get cooler and eventually recover.

What do you think?? Any practical experience to share?



Marathon Talk did a 3 part training article with Dr Mark Hetherington on Heat and hydration (part one of three) starts at 48 mins into podcast
http://traffic.libsyn.com/marathontalk/EP70b.mp3you can listen to parts 2-- Heat and hydration with Dr Mark Hetherington (part two of three) starts at 50 mins http://traffic.libsyn.com/marathontalk/EP71.mp3
And part 3 here
starts at 6 mins into podcast Training Talk

- Dr Mark Hetherington answers your questions in the third of our three part Training Talk on heat and hydration
Some good sokis advise, hope it helps Roberto


opps seemed to have given you a bad link!
Try this
then check also episodes 71 and 72 for parts two and tree.
think you should find some useful tips on dealing with the heat.