The Truth About Target Heart Rates
I know. You’re probably saying “here he goes again” and you are correct. You’re thinking “Come on, don’t attack the target heartrate zone idea too”. Sorry. Here we go again. Every time I have this conversation with a group I always get the question “ If this stuff isn’t true, why is it plastered on the front of every treadmill”. I can’t really answer except to say that it probably came out of the legal department.
The truth is that target heartrate zone training is a highly flawed concept that could result in us drastically overtraining or undertraining ourselves or a client. Why is it a flawed concept? Because the physiologists know that only a small percentage of the population actually fits the formula. Did you know that seventy percent of the population is plus or minus ten to twelve beats from the theoretical 220- age formula. Yes seven out of ten people don’t fit the mold. Even worse, thirty percent of the population deviates nearly twice that much.
In mathematical terms for seventy percent of the population maximal heartrate actually equals:
220 – age plus or minus 10-12 beats per minute
For thirty percent of the population maximal heartrate actually equals:
220- age plus or minus 20-24 beats per minute
Why is this such a big deal? To realize why, we need to first state that those whose heartrates are on the high end are at little to no risk. All that happens with those folks is that we don’t push them hard enough. The problem is with the folks who have an unusually low maximum heartrate. If we were to push a person in the thirty percent group that is minus twenty-four beats per minute to eighty percent of their theoretical maximal heartrate, we would actually be pushing them to ninety percent. This would be a major error that could have significant ramifications.
The lesson here is that, as with so many of the so-called truths of fitness, there is actually significant variability in what we seem to think is an accurate and time-honored formula. Be careful with yourself and with you clients. Buy a heartrate monitor and learn how both you and your clients really respond to exercise.