April 9, 2005 at 11:05 pm #2396
Donald Kirkendall, an exercise physiologist at the University of North Carolina, will never forget the time he put a heart-rate monitor on a member of the United States rowing team and asked the man to row as hard as he could for six minutes.
The standard formula for calculating how fast a human heart can beat calls for subtracting the person’s age from 220. The rower was in his mid- 20’s.
Just getting the heart to its actual maximum rate is an immense effort and holding it there for even a minute is so painful that it is all but inconceivable for anyone who is not supremely motivated, Dr. Kirkendall said. But this rower confounded the predictions.
“His pulse rate hit 200 at 90 seconds into the test,” Dr. Kirkendall said. “And he held it there for the rest of the test.” A local cardiologist was looking on in astonishment and told Dr. Kirkendall, “You know, there’s not a textbook in the world that says a person could have done that.”
“I’ve kind of laughed about it over the years,” Dr. Haskell said. The formula, he said, “was never supposed to be an absolute guide to rule people’s training.” But, he said, “It’s so typical of Americans to take an idea and extend it beyond what it was originally intended for.”
April 11, 2005 at 3:49 am #18264
Interesting article…I do agree with the inaccuracy of this formula. I train with a heart rate monitor and I very rarely (if not ever) get to my predicted maximum HR (I’m 21) excluding heart rate drift. My highest and most accurate reading is in the upper 180s to low 190s while in a VO2 max interval or a very hard set of hill repeats, which is low considering that 199-200 is my predicted maximum. And I know that max HR differs between individuals as well-I know a few people with very high max HRs (over 200) and others including myself with lower than the predicted values. Is there a more accurate way to determine max HR other than running all out up a steep hill?
April 11, 2005 at 12:43 pm #18265
The ‘formula’ for estimating maximum heart rate was never meant to be applied to individuals. Statistically speaking, in a large enough sample, the average maximum heart rate for the group approaches the value the formula predicts.
My ‘predicted’ mhr using the classic 220-age formula (47 yo) is 173. My actual highest recently observed heart rate is 189. I often run workouts at or above 173. In my case the formula is off by a large amount.
Some writters feel this formula is a better predicter of mhr: 205-(age/2).
This yields a 181 which is low but closer to my actual maximum.
Another problem is the misapplication of percentages to the maximum heart rate. The ‘better’ method is to apply percentages to heart rate reserve (the difference between maximum and resting heart rate).
For example if I do a long run at 75% of mhr the rate is 142. But using heart rate reserve (mhr-rhr)*% + rhr (where rhr is resting heart rate, in my case 43) the value at 75% is 152. This higher value is a very comfortable pace so clearly 142 would be too slow.
At least for me, I find it works best to simply run based on feel. The only time I wear a HRM is on the treadmill (I am usually on the mill only to do hill workouts). For hill workouts the hrm helps me determine if I am pushing myself to hard. Since I don’t run hills often the extra feedback helps (and also adds some interest to the otherwise boring treadmill).
April 11, 2005 at 5:25 pm #18266
The article does offer what those scientists suggest is a more accurate estimation but one of the points is that any formula is going to be just an estimation and that people should be careful not to fall into the trap of using something as much more than it was intended to be.
The most important thing I took from that article and from discussion of the article with a few people I know is that not even scientists know the best way to determine max heart rate. Many heart rate training proponents say that the reason for using heart rate training is because it is an exact science and it is easier to precisely determine proper training intensities than using other signals from your body. However, here we have a situation where even scientists have trouble determining the right way to get the number that is used as the basis for this training, which shows just how “exact” and “precise” this science is. I know when I was trying HRM training, I had to modify my numbers a few times when I found my heart rate going above even tested maximums. Combine that with misunderstandings about things such as whether percentages of intensities should be based on maxHR or HRR (some workout plans use one and some use the other, some don’t tell you what they are using) and it shouldn’t be hard to see why many people simply get lost when trying to train with them.
As was pointed out in the article, the best use for heart rate still seems to be to monitor how quickly you recover from a workout. If your heart rate drops significantly in the first minute or two after you complete a workout, you are in good shape. If the drops are not as precipitous, this is a sign that either you are not in very good shape or you are over fatigued and need to work more recovery into your training routine.
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