Question: HR at low elevation vs. high

Triathlon Forum
1

I thought there are a few guys with smart hearts out there that I could reach out to!

My question is whether or not a maximal effort at different altitudes will yeild different avereages on the bike. Let’s say that you are racing 20k at sea level and another at 6000ft.

If there is a difference on the bike, how about running?
I assume power would be a bit lower? Thanks.

PT

2

depends on how long you’ve been at 6000ft prior to the race.

3

Let’s do a few scenarios:

  1. no time at all, just showing up the day of the race.
  2. Whatever the time it is to aclimate.

Thanks agian!

PT

4

different avereages on the bike.\

Are you talking about average speed, or average HR???

5

I am talking heart rate…

6

This is a good question. I’ve wondered what actually determines heart rate. I generally live around sea level, but went on a business trip to Denver last year. While there I went for a few short runs and had a heck of a time catching my breath. It was very difficult to run (as in very high perceived exertion), but when I stopped and took my pulse, it was zone 2.
I wondered, based on that experience, if the heart rate is determined by the amount of oxygen it has available to circululate?

7

At similar speeds, your heart rate will be higher at altitude. So lets say you are running a tempo run… 85-90% max HR, you will have to run slower to stay in that range. Hills will give you a big spike. If you are doing a race pace workout, or any workout where you are mostly concerned with pace, take longer rests.

Even if you are acclimated… or even lived at altitude your whole life… this still holds true. There is less air regardless of how acclimated you are.

8

Complex question and like everything else…it depends.

Read the following article for details on acclimatization to altitude. It is very well done: http://www.sport-fitness-advisor.com/acclimatization-to-altitude.html

Beyond that the simple answer is: Submaximally your HR will be higher trying to produce work. At race pace, ultimately, it will be lower. At or near max or race pace you will see a clear decline in Vo2, a decreased capacity for work, a decrease in cardiac output, a decline in power output, an increase in blood lactate, and an overall decline in performance.

When trying to do an event such as a short TT (20k) as mentioned above, based on all of the above, you will not (in most cases) be able to maintain as high of a HR as you are used to. In many cases it is as simple as an athlete not experienced with altitude going out too hard, pooling lactate, and slowing down. This can fly a little bit in the face of science but all our bodies are not the same and we are not machines. Everything is dependent and based on Vo2 vs leg strength as well.

If you are just out for a tempo run or ride your your HR will be higher than normal to maintain normal power and/or speed readings. Near max efforts are very different.

The best bet…arrive at the event in question less than 2 hours prior to the start. When I raced MTB I would stay at the base of the Mt and drive up the morning of. Unless you have 3 weeks to hang out it’s your best bet.

Scott Blanchard