Heat stress and HR zones
Hi!
My name is Tomer, and I lately started training toward the Israman IM at the end of January 2010. Though at this early stage I’m still undecided on whether I’ll go for the half distance or the full deal, I’m now on the 5th week of the ultra distance program.
Usually my favorite training time is early morning. But with most days having double sessions, I find myself training quite a lot at the evenings or late mornings (after 8AM) as well. With the summer on us, temperatures here are at the 30’s C (90’s F), and the humidity makes it even worst. What I find out that under these conditions I am no longer able to maintain the required HR zones, and my HR sores, especially at the lower range. For example – where I am supposed to run at 60% (122 BPM) I am actually at 135-140. The gap diminishes as I get into the higher HR zones, where at 84% my predicted HR (158) and actual (160-163) are getting in line. Even when walking back after the end of the session, my HR which usually drops in few minutes of walking into the 90’s, keeps above 110 for a long time.
As a result, in this sessions I have started using subjective feeling to decide on the level of effort, and rely less on the HRM. I wanted to know if you have any advice on how to objectively measure efforts under these conditions, and how to pass the long summer months (but the obvious “drink lot’s of water” :-) )
Best regards,
Tomer
My name is Tomer, and I lately started training toward the Israman IM at the end of January 2010. Though at this early stage I’m still undecided on whether I’ll go for the half distance or the full deal, I’m now on the 5th week of the ultra distance program.
Usually my favorite training time is early morning. But with most days having double sessions, I find myself training quite a lot at the evenings or late mornings (after 8AM) as well. With the summer on us, temperatures here are at the 30’s C (90’s F), and the humidity makes it even worst. What I find out that under these conditions I am no longer able to maintain the required HR zones, and my HR sores, especially at the lower range. For example – where I am supposed to run at 60% (122 BPM) I am actually at 135-140. The gap diminishes as I get into the higher HR zones, where at 84% my predicted HR (158) and actual (160-163) are getting in line. Even when walking back after the end of the session, my HR which usually drops in few minutes of walking into the 90’s, keeps above 110 for a long time.
As a result, in this sessions I have started using subjective feeling to decide on the level of effort, and rely less on the HRM. I wanted to know if you have any advice on how to objectively measure efforts under these conditions, and how to pass the long summer months (but the obvious “drink lot’s of water” :-) )
Best regards,
Tomer
Replies to This Discussion
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Permalink Reply by Steven T. McLean on -
Tomer,
I live in Michigan and it has been a very cool spring. Today was the first day with temp up to 92 and I did a 1:30 ride in the heat and humidity. I also discovered that my HR soared much higher than usual and even at a slower pace. I think we will adjust to the conditions but it will take some consistent training to do so. I hope Mike can give us an answer as to how to train at this point, stay with HR zones or switch to perceived effort.
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Permalink Reply by Jorge Ruiz on -
The heat and humidity definitely take a toll on HR. Living in Miami and trying to get my runs in at lunch time (90's ++), yes it makes a huge difference.
However, it preps you for race day since you will be riding and running in similar temps.
Hopefully Mike can give us some suggestions if we need to adjust HR to account for this, but I really think there is nothing we can do but suck it up.
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Permalink Reply by Tomer Geminder on -
I came uppon the following in a presentation about acclimatization for different conditions:
Heat Acclimatization
- Ability to get rid of excess heat improves with practice
- Sweat sooner, sweat glands produce a greater volume of sweat, and the sweat is more diluted (less concentrated, less mineral loss)
- Reduced blood flow to skin because of better sweating; more available to muscle
- Blood volume increases
- Heart rate increase is less (than nonacclimatized)
You can achieve heat acclimatization by exercising in the heat for 1 hour or more each day for 5 to 10 days. Cardiovascular adaptations occur within the first 3 to 5 days while changes in sweating mechanisms may take up to 10 days. Reduce exercise intensity to 60% to 70% the first few days before resuming more intense workouts.
So, the effect the higher heat stress minimise with time and expossure to heat (already doing much better, though keep try to avoide the heat of the day as possible).
And on teh negative side - if we are not sweating enough, we can expect to sweat even more, even under milder conditions - not sure how everybody would apreciate this ;-)
Tomer
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