Monday, April 12, 2010

The Truth About Target Heart Rate Zone Training

If you've used any piece of traditional cardiovascular equipment (treadmills, elliptical trainers, stationary bikes, steppers, etc), you've undoubtedly seen the little graphs and charts on the display screens suggesting you train in your "target heart rate zone" while performing what is considered to be traditional cardiovascular exercise. These charts suggest, based on your age, what range-in heart beats per minute-you should be training in in order to receive a beneficial cardiovascular workout. In fact, entire well respected organizations within the fitness industry have developed their entire set of training guidelines for exercise prescription based around heart rate zone training.

So, "what of it"? Are these heart rate formulas valid? Are they effective? I think the answers may surprise you.

The entire premise behind this set of guidelines is that you can calculate your theoretical maximum heart by simply subtracting your current age from 220. So, if you are 50 years old, your theoretical maximum heart rate is 170 beats per minute. Many fitness organizations suggest you should train somewhere between 60 & 85% of your maximum heart rate for 20-60 minutes 3-5 days/week. So, going back to the 50 year old person, if their theoretical max heart rate is 170, they should be exercising in a range of 102-145 beats per minute.

Pretty straight forward, right? Well, yes, but here is the problem: research has shown that, for 70% of the population, the true maximum heart rate is plus or minus 10-12 beats. So, the 50 year old who is under the impression that their max heart is 170 actually may have a max of 158 to 182. For the other 30% of the population, things get even worse: true max heart rate can be plus or minus 20-24 beats. So, going back to our reference 50 year old person, depending on where they fall, their max heart rate might be 146...or it might be 194!!

You can see why trying to develop an exercise prescription or cardiovascular training program based on the old "220-your age" formula is terribly flawed. If you use this set of guidelines and apply them to your workouts, you may be under training, or worse yet, over training and over exerting. The under training situation isn't all that problematic (although you may not be getting a hard enough workout), but, if your true max heart rate is 24 beats less than what the formula suggests, you can be exercising entirely too hard, and, if you are a beginning exerciser with a history of cardiovascular health problems, the situation can be down right dangerous.

So, what's the take home message? Only use the 220-minus your age heart rate zone training philosophy as a very very rough guideline. I'd suggest using rate of perceived of exertion (RPE) on a 1-10 scale as a way to gauge exercise intensity. 1 on the scale means the training intensity is ridiculously easy and 10 means you are nauseous, terribly out of breath, and you know you cannot sustain the exercise for more than a couple of minutes without having to stop and lie down on the floor. For most, an RPE of 6-8 is about right if you are going to perform steady state exercise for 20-30 minutes (and I could write an entire series of articles as to why I don't like this approach as a primary means of receiving a cardiovascular workout but I digress).

Here's to training smarter and more effectively!

PJ Striet

PS-if you want to take advantage of my distance coaching and program design service to ensure you are training correctly and to avoid having to figure any of this stuff out on your own, just shoot me an EMAIL with "Distance Coaching" in the subject line. 
 

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