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confused about my LT...(4 posts)

confused about my LT...Gall
Jan 27, 2003 5:35 PM
Hello again,

I did a LT test the other week on my indoor trainer. I did the 30 min all out and took the average of the last 20 mins. The results of this test showed that I had a LT of 176.

Anyhow, I look at the trainingbible site. And there is a discussion saying that when you use an indoor trainer to do a LT test the results might be higher or lower then your actual LT. They are saying this is the results may vary due to your body heat and motivation.

When I took the test I had plenty of motivation but I was sweating like mad. I didnt use a fan like they suggested.

So my question is... should I take a few beats off my results to make up for my 'body heat beats'?


Heat mattersKerry
Jan 27, 2003 5:58 PM
IME, my HR during a time trial (essentially the LT test) can easily go up 5 beats as the temp goes from 20 to 30 C (68 to 86 F). Does that mean my LT changed? No, but it means that if I am going to focus on HR training, I need to know my LT as a function of temperature. What you did on the trainer was to determine your LT at something like 100F (hard to determine exactly the applicable temp). Now go back and do it outside at some known temperatures, and then you'll have some useful information.
One more thing...Jon Billheimer
Jan 27, 2003 6:37 PM
Studies on heart rate variability show an amazing possible range due to not only heat, but rate of evaporation, barometric pressure, diet, state of training, etc. So while you're following Kerry's suggestion, also, take note of rate of perceived exertion and try to correlate that with varying heart rates. That will give you a check against which you can evaluate heart rate differentials on different days and under differing circumstances.
Good advice...James OCLV
Jan 27, 2003 7:05 PM
Both replies to your post offer very good advice. One other thing to keep in mind is that you shouldn't get too obsessed with this number. Remember, unless you determine your LT in a lab it's just an estimate. Jon's suggestion to use RPE along with your HR is a good one. Because LT can vary from day to day based on diet, temperature, recovery, etc. it's important to learn how to interperet what your body is doing based on "feel".

I know that you need this number to establish your training zones; and its variability is why most zones have a "range". Is there any reason (based on feel) that you might think that this number might be skewed? Use the results of other tests you've done, training and racing to validate this number. You can (and should) test yourself again in about 4 weeks or so. In the weeks before your next test, try to judge by "feel" whether or not the zones that you came up with are correct.