|heart rate formula debunked?||ET|
May 2, 2001 9:48 AM
|Below is an article from the New York Times:
April 24, 2001
'Maximum' Heart Rate Theory Is Challenged
By GINA KOLATA
Donald Kirkendall, an exercise physiologist at the University of North Carolina, will never forget the time he asked 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."
But maybe, some physiologists and cardiologists are saying, the textbooks are wrong.
The question of how to find maximum heart rates is not just of academic interest, medical experts say. The formula for calculating the maximum rate has become a standard in cardiology and in fitness programs, and an entire industry has grown up around it, with monitors sold to individuals and built into exercise equipment.
"There is a need, a clinical and societal need, to estimate the maximum heart rate," said Dr. Douglas Seals, an exercise physiologist at the University of Colorado.
Doctors use the formula when they test patients for heart disease, asking them to walk on treadmills while the speed and incline are gradually increased until their heart rates reach 85 percent of the predicted maximums.
The idea is to look for signs, like chest pain or a sudden drop in the heart rate, indicating that the heart is not getting enough blood. But if doctors underestimate how fast the person's heart can beat, they may stop the test too soon, Dr. Seals noted.
Personal trainers and exercise instructors design fitness programs around the maximum heart rate, often telling people to wear heart rate monitors and then to exercise at 80 to 90 percent of the maximum in brief spurts to build aerobic capacity and at 65 percent to 75 percent to build endurance.
Some heart monitors built into exercise machines even shut the machines down if an exerciser exceeds 90 percent of the predicted maximum. But if the heart rate formula is wrong, these exercise prescriptions are misguided.
"If you're trying to improve their aerobic fitness or to train for certain endurance events, then you want to know with a reasonable accuracy what intensity you're exercising at," Dr. Seals said. "If your estimate is 10 or 20 beats too low, then you're pretty far off."
Exercise physiologists say, however, that being pretty far off is more common than most people expect.
"The more information we have, the more we realize that that formula is just a very rough consideration," said Dr. Jack H. Wilmore, an exercise physiologist at Texas A&M.
And while Dr. Seals is now proposing a new formula to use as a general guide, he and others say it is simplistic to rely on a single formula to predict the maximum heart rates of individuals.
The common formula was devised in 1970 by Dr. William Haskell, then a young physician in the federal Public Health Service and his mentor, Dr. Samuel Fox, who led the service's program on heart disease. They were trying to determine how strenuously heart disease patients could exercise.
In preparation for a medical meeting , Dr. Haskell culled data from about 10 published studies in which people of different ages had been tested to find their maximum heart rates.
The subjects were never meant to be a representative sample of the population, said Dr. Haskell, who is now a professor of medicine at
May 2, 2001 9:50 AM
|The subjects were never meant to be a representative sample of the population, said Dr. Haskell, who is now a professor of medicine at Stanford. Most were under 55 and some were smokers or had heart disease.
On an airplane traveling to the meeting, Dr. Haskell pulled out his data and showed them to Dr. Fox. "We drew a line through the points and I said, `Gee, if you extrapolate that out it looks like at age 20, the heart rate maximum is 200 and at age 40 it's 180 and at age 60 it's 160," Dr. Haskell said.
At that point, Dr. Fox suggested a formula: maximum heart rate equals 220 minus age.
But, exercise physiologists said, these data, like virtually all exercise data, had limitations. They relied on volunteers who most likely were not representative of the general population. "It's whoever came in the door," Dr. Kirkendall said.
In addition, he and others said, gauging maximum heart rates for people who are not used to exercising is often difficult because many prematurely stop the test.
As the treadmill hills get steeper, people who are not used to exercise will notice that their calves are aching. "They will say they can't go any further," Dr. Kirkendall said.
In addition, Dr. Wilmore, the exercise physiologist, said it was clear from the scattered data points that maximum heart rates could vary widely from the formula. "If it says 150, it could be 180 and it could be 120," Dr. Wilmore said.
But the formula quickly entered the medical literature. Even though it was almost always presented as an average maximum rate, the absolute numbers took on an air of received wisdom in part, medical scientists said, because the time was right.
Doctors urging heart patients to exercise wanted a way to gauge exercise intensity. At the same time, exercise gurus, promoting aerobic exercise to the public, were asking how hard people should push themselves to improve their cardiovascular fitness. Suddenly, there was a desire for a simple formula to estimate maximum heart rates.
"You tell people to exercise at a moderate intensity," Dr. Haskell said. "Well, what's a moderate intensity?"
Soon, there was a worldwide heart-rate monitor industry, led by Polar Electro Inc, of Oulu, Finland, selling more than 750,000 monitors a year in the United States and citing the "220 minus your age" formula as a guide for training.
|everything I've ever read on the subject (other than, like, a||bill|
May 2, 2001 10:04 AM
|blurb in Parade Magazine) has pointed out that the formula (220 - age) once thought a reasonable guide was flawed to the point of useless.|
|re: heart rate formula debunked?||Mel Erickson|
May 2, 2001 10:55 AM
|The formula is not flawed. It is what it is, an average based on a fair number of actual measurements. We can debate whether the population on which it was based was representative but it doesn't necessarily mean there is a flaw in the formula. The flaw is is how the formula is applied. The infamous bell curve comes into play here. Like any average there are those that fall above and below the average. We know you can't take an average and apply it to a general population where there is a fairly large standard deviation, as is the case in MHR. The only way to accurately determine the MHR for an individual is to test that individual, not apply a formula. The formula is fairly useless but not because it is flawed.|
|re: UR right formula isn't flawed, the idea there is||cyclopathic|
May 2, 2001 11:35 AM
|such formula is flawed!|
|if better science criticizes the formula because the data that||bill|
May 2, 2001 12:21 PM
|contributed to its original formulation were flawed, which is what seems to be the point of the study, I'd say that the formula is flawed. |
But, even so, point well taken as to the distinction -- lots of deviation doesn't necessarily mean that the formula is flawed.
May 2, 2001 12:32 PM
|but we don't really know the population that was studied. I seem to recall that it was a fairly sizeable number. Even if they weren't randomly selected it probably represents the total population well enough for the statistical purposes of this formula. Nonetheless, it's all academic, literally and figuratively. It has no practical application.|
|formula for fit individuals||no excuses|
May 2, 2001 11:27 AM
|I've posted the article on this topic before regarding max HRs, but the formula that was stated for fit individuals (obviously 99% of the posers on this site) is 206 - 1/2 your age.
For me 206-24= 182, which is right on to what I usually see in high energy 45 minute spinning classes as far as the 60%, 70%, exertion levels.
|Formula for fit and older||sidley|
May 2, 2001 12:59 PM
|The above-mentioned "fit formula" predicts essentially the same maximum heart rate for 25 and 35 year olds as the standard 220 - age formula. The fit formula really only predicts different max heart rates for those posers among us who are either over 35 or under 20 and even then the differences are around 6 heartbeats. For instance, I am 27 and there is no real difference between the two. 206 - 13.5 = 192.5. Whereas 220 - 27 = 193.|
|What's Your Point?||grz mnky|
May 2, 2001 3:01 PM
|Anyone who has taken the time to do just a tiny bit of reading on the subject or has used a HR monitor immediately realizes that the 220 minus your age is a rough estimate at best. In fact the only strict rule is that there is no universal rule for an indiviual's HR. Pick up any of the books on the subject of HR training and you'll see that this is pretty much the first point all of the author's make. Throw in all the various factors (for which there is also no formula) and you have a real mess. The best thing to do is determine your own max HR and work from this. If this is the first time you've been exposed to this then let me apologize up front and be the first to welcome you to the real world. |
So this gets me to my question: what is *your* point other than wasting some bandwidth to reproduce an article, without the author's permission, I assume, that adds nothing new to the debate? The NYT is a fine source, but it's hardly the place to turn for definitive meidcal advice and we all know that reporters sometimes get things mixed up since they usually aren't experts on the given subject.
Like the kids say, "Duh."
BTW - what kind of bike do you ride - we can tell a lot about a person from that y'know ;-)
|hey, go easy on the cappuccino, will you?||ET|
May 2, 2001 3:54 PM
|Isn't your tone a little on the harsh side? I don't think the others who contributed to this thread viewed it as a waste of bandwidth. And I'm certainly not the first to copy an article without permission either, but you didn't criticize others for this.
BTW, several months ago, with your usual social charm, you took up bandwidth to say more or less that I was a moron for suggesting that it never pays to sit up in a tailwind, at least for all but typhoon conditions, but then I couldn't find any input parameters in the wind model in analyticcycling.com to back up your claim, thereby supporting my claim, and you said you'd get back to me after you looked over the model. Well, I'm still waiting, months later. Perhaps you'd like to use some valuable bandwidth for that, Mr. Physics know-it-all.
|You Should See Me on Meth||grz mnky|
May 2, 2001 4:05 PM
|ET - what's that stand for, Extra Testy? |
The guy took two full posts to plagerize an artilce and had zero to add, gee thanks. I'm gonna go find me some drivel to reproduce and see how long you guys spend debating it. What is he doing, selling subscriptions to the NYT?
How do you keep a moron in suspense?
I'll tell you tommorow....send me your email.
Enroll in a basic freshman physics course and pay attention when they get to vectors.
You should see me on a bad day when I really can't suffer fools.
|I for one found the origins of the debunked myth interesting,||bill|
May 2, 2001 4:46 PM
|as well as the subsequent science, such as it is, which, if not related as thoroughly as it may have been in Science or Nature or even the NE Journal of Medicine, appeared in the NEW YORK TIMES for heavens sake. If worthy of the Times, I think that we can catch a little on the friggin RBR BB. |
Lighten up, my wound up friend. You're not always cute when you're angry.
|Does This Make My Butt Look Big?||grz mnky|
May 2, 2001 5:29 PM
|I've got to be something more than all ass. |
So maybe a link to the site would have been better. This isn't even news worthy since it's been known about for a LONG time - check the publication dates on most of the accepted HR training books.
Yes I get wound up - that's why they limit me to one cup of coffee per day and only give me safety scissors and keep me in a padded cube. I ain't even close to angry - in fact I'm having a great day! You should see me when I'm pissed off.
So, should I start plagerizing every article that I think is interesting from the NYT to educate and titilate you? How about I start reproducing entire chapters from my engineering and physics text books on issues that I think are interesting or the next time some one asks a techie type of question that could really serve as a launch pad to a canon on things Newtonian? Things in the mechanical world are a lot more cut and dry and we could cut people off at the knees and stifle any debate or discussion. Grz Mnky would be the random jugernaut, free radical, and court jester all in one. Maybe this isn't such a good idea?
|it's getting bigger||ET|
May 3, 2001 8:22 AM
|First of all, you're wrong. I did not plagiarize. Apparently you don't know what the word means, because I did not use its contents or ideas as my own. I clearly attributed it to the New York Times, and its author and date were given. I needed two posts because it wouldn't all fit in one. I should've given a link, you say? Well, yes, but I couldn't. A PhD mathematican, who is also a co-worker and fellow cyclist, and no doubt a fellow moron in your eyes, found it interesting enough himself that he emailed the article's link to the other cyclists in the office, but the link didn't work, possibly because one has to register to access the NYT on the Web, something I've already done, or perhaps for other reasons. So I accessed the article (in its archives), copied it and posted it here just in case some others would find it interesting, which apparently some did. Sure, maybe some have known about it for a long time, but obviously many didn't or don't, including, apparently, some exercise physiologists themselves. And there is a relationship to cyclists monitoring their heart rates. So is it such a waste posting the article, possibly helping some fellow cyclists in the process?
Concerning whether one should sit up or stay aero in a tailwind, yes, I've taken freshman physics and understand vectors, but the wind issue isn't as clearcut to those who are not as intellectually superior as yourself. It's a question of increasing the rear surface area but also the frontal drag vs. having a smaller rear surface area but much less frontal drag, and all the input parameters I tried, and it was many, all resulted in aero being better than sitting up. The least you could've done is kept your word and got back to me as you said you would, especially after disparaging me the first time. It could just be (no, I'm not certain) that you're wrong.
I don't think this is about just another article. I can venture some guesses, e.g. it's personal and you just can't stand me for some reason and this was just itching to get out, or you have zero social skills, or you randomly get ticked off at times, or maybe all of the above.
Your posts are way out of line, their style not really proper on a forum, and I don't care if there are 5,000 silent types and just Bill (thanks, Bill) who is brave enough to say so.
|Much Ado About Nothing!!||SimpleGreen|
May 2, 2001 5:48 PM
|The mean decreases linearly via the formula 220-age. So what? That's just a trend. The real problem is that people in the business yearn for a formula. The foolish thing to do is to just use the average as a "formula", when the variance is so large.
Think about it this way. How many of you calculate your height or weight or annual salary by looking at the averages for the entire US population? Seems silly in those contexts, but that's what one is doing by using the "formula". The incorrect use/interpretation of data is the problem. The only information one can get from the data is that over time your max HR will decline, and there is a formula for the mean. It's funny how such a basic statistical result gets twisted and interpretted to the point of causing a controversy.
The closest thing to a "formula" for determining your max HR is to ride hard for 5 minutes and then hammer up a steep climb like a madman. Blow up like a roman candle!!
|Well, I guess I'm average||tommyb|
May 2, 2001 7:52 PM
|No matter how many times I try, my max heartrate always ends up being within a beat or two of 220 - my age. Therefore, the formula must be right, and the rest of you are just abnormalities outside the specified standard deviation. Data from you will not be considered as valid. Sorry.|| |