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10 Feb 2004

Heart rate Zones
I am a 37 year old male in very good shape, I recenlty completed a 75 km mountain bike race in 3h48 with an average heart rate of 171. This appears to be very high, am I at risk competing at this intensity for such a long duration?

Many thanks
Answer 378 views

01 Jan 0001


I would not think so, although there is a small possibility that a high heart rate indicates a problem. HOwever, the fact that you could exercise for this long at such a heart rate and not feel any adverse effects seems to indicate that it's not a problem. Generally, this level of stress would cause some sort of symptom - perhaps pain, if there was a problem.

So, rather than being a problem, I would say that in your case, the really high heart rate is just an exception to the rule. You must remember that a lot of generalizations are made when it comes to heart rate and exercise. Do not get caught up in to believing the heart rate monitor as the final authority in your fitness level. The best way to use your heart rate monitor is to use it to compare training sessions from week to week. Therefore, if you train one day doing a particular session, take note of your heart rate. The next time you do the exact same session (say 30 minutes cycle at over the same route, assuming the conditions are similar), you should be able to compare your heart rate during the session. If it is lower, then it indicates that you are fitter than before, and your training is going well. If it is higher, then it shows that you are either tired, or training too hard or are possibly becoming ill. This is a sign that you are in need of a few easy training days.

It is important that you don't think of heart rate as the absolute indication of fitness or health. It is the differences between heart rates in exactly the same session that is important, and understanding how your own individual heart rate differs from week to week will allow you to train with great precision.

Lastly, remember that heart rate depends on many factors - hydration, mood, stress levels, temperature and so on. Therefore, if your heart rate is not exactly what you think it should be, don't worry too much. Rather look at long term changes and patterns in heart rate, and try to interpret them as I explained above.
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