What's the deal with Target Heart Rate

[amirm]

Hi Myles. Thanks for taking the time to answer our questions.

My question is pretty basic I think. What is the magic around the target heart rate? Why do the formulas for it rely on age? What happens if you are above 80%? Saw on TV that it can cause one to burn muscle and hence is no longer good for your heart???

Why is it that sometimes I have an easy time getting my rate into the target zone but other days harder? Is it good for it to not want to rise up to that rate easily???

 

[flez007]

+1

 

[MylesBAstor]

Hi Myles. Thanks for taking the time to answer our questions.

My question is pretty basic I think. What is the magic around the target heart rate? Why do the formulas for it rely on age? What happens if you are above 80%? Saw on TV that it can cause one to burn muscle and hence is no longer good for your heart???

Why is it that sometimes I have an easy time getting my rate into the target zone but other days harder? Is it good for it to not want to rise up to that rate easily???

Haven't forgotten Amir! Will give you a response in a day or two!

 

[amirm]

No worries Myles. Thanks for taking the time to do so.

 

[MylesBAstor]

OK Mike Boyle said it best so no need recreating the response!

http://www.coreperformance.com/daily/movement/q-a-heart-rate-training-zone.html

Also:

The Problem with Formulas

At least 70% of the population does not fit into our age-old theoretical formulas. Strangely enough, when I write this fact I often get angry responses from the physiology crowd. However, it does not become less true. The 220 minus age formula is flawed on two key points. One, it doesn't fit a significant portion of the population. Two, it is not based on research. Even the developer of the now-famous formula admits that his thoughts were taken out of context. The more accurate method is called the Heartrate Reserve Method or Karvonen formula.

Karvonen Formula (Max HR- Resting HR) x %+ RHR= THR Ex- (200-60) x.8 +60 = 172

The key to the Karvonen formula is that it looks at larger measures of fitness by incorporating the resting heartrate and is therefore less arbitrary.

I will add this piece about measuring resting heart rate by Perry Nickelston:

http://pjbarry62.ipage.com/2010/07/17/are-you-overtraining-2/

Hope that helps more than confuses.

 

[Whatmore]

Myles, thanks for the info, very useful.
One question though, how do you measure your maximum heart rate?

 

[Speedskater]

Just some random thoughts:

a] The target heart rate formulas have caused more individuals anguish than almost other any well-meaning statement.

b] The original 220-age formula was a very informal statement at a sports seminar, then it took on a life of it's own..

c] These formula's only come close when averaged with a very large group of people.

d] Sally Edwards tested groups of competitive triathletes and found rates all over the place.

e] Maximal Heart Rate is sport specific.
Swimming, Cycling and Running will each have a different value.

f] Edmund R. Burke writes:
The most accurate way to determine your MHR is to have it clinically tested.
If you are over age 35 and/or are not in great physical condition, do not take a self-administered field tests.

If you really like to read, Tim Noakes, MD has a 900 plus page book on the subject.

'Lore of Running'

 

[RBFC]

Just some random thoughts:

a] The target heart rate formulas have caused more individuals anguish than almost other any well-meaning statement.

b] The original 220-age formula was a very informal statement at a sports seminar, then it took on a life of it's own..

c] These formula's only come close when averaged with a very large group of people.

d] Sally Edwards tested groups of competitive triathletes and found rates all over the place.

e] Maximal Heart Rate is sport specific.
Swimming, Cycling and Running will each have a different value.

f] Edmund R. Burke writes:
The most accurate way to determine your MHR is to have it clinically tested.
If you are over age 35 and/or are not in great physical condition, do not take a self-administered field tests.

If you really like to read, Tim Noakes, MD has a 900 plus page book on the subject.

'Lore of Running'

Excellent post.

Most folks aren't aware of the different heart rate limits for different activities. Intra-thoracic pressure, which differs widely depending upon the chosen activity and one's posture, etc. while engaged, is a factor in cardiac output and diaphragmatic excursion. Sometimes, it's not such a good idea to "dumb things down" for the masses.

Lee

 

[MylesBAstor]

Myles, thanks for the info, very useful.
One question though, how do you measure your maximum heart rate?

1. Stress test with cardiologist.
2. Best estimate according to paper in 2001 is 220-0.8 x age.

 

[amirm]

Thanks for the info guys but my question remains . What happens if I am over or under some? Let's say my target is 130. What happens at 120? 140? What if I am at 120 one day and 140 the other?

A related but I suspect harder question: I have the option of getting to my target through speed (faster peddling) or resistance (more effort). Is one better than the other? When I did my echo cardio, they kept increasing the effort (incline of the threadmil).

 

[MylesBAstor]

Depends on your goals.

You can't do the same intensity every day.

All things being equal, you're better off increasing the intensity/difficulty of the exercise.

 

[Steve williams]

Thanks for the info guys but my question remains . What happens if I am over or under some? Let's say my target is 130. What happens at 120? 140? What if I am at 120 one day and 140 the other?

A related but I suspect harder question: I have the option of getting to my target through speed (faster peddling) or resistance (more effort). Is one better than the other? When I did my echo cardio, they kept increasing the effort (incline of the threadmil).

They increase the rate and incline of the treadmill in an ECHO EKG in order to reach your desired heart rate for your age and yes they use 220 - your age

 

[MylesBAstor]

Age-Predicted Maximal Heart Rate Revisited
Hirofumi Tanaka, PHD, Kevin D. Monahan, MS, Douglas R. Seals, PHD
Boulder and Denver, Colorado

OBJECTIVES We sought to determine a generalized equation for predicting maximal heart rate (HRmax) in
healthy adults.

BACKGROUND The age-predicted HRmax equation (i.e., 220 2 age) is commonly used as a basis for
prescribing exercise programs, as a criterion for achieving maximal exertion and as a clinical
guide during diagnostic exercise testing. Despite its importance and widespread use, the
validity of the HRmax equation has never been established in a sample that included a
sufficient number of older adults.

METHODS First, a meta-analytic approach was used to collect group mean HRmax values from 351
studies involving 492 groups and 18,712 subjects. Subsequently, the new equation was
cross-validated in a well-controlled, laboratory-based study in which HRmax was measured in
514 healthy subjects.

RESULTS In the meta-analysis, HRmax was strongly related to age (r 5 20.90), using the equation of
208 2 0.7 3 age. The regression equation obtained in the laboratory-based study (209 2
0.7 3 age) was virtually identical to that obtained from the meta-analysis. The regression line
w
CONCLUSIONS 1) A regression equation to predict HRmax is 208 2 0.7 3 age in healthy adults. 2) HRmax
is predicted, to a large extent, by age alone and is independent of gender and habitual physical
activity status. Our findings suggest that the currently used equation underestimates HRmax
in older adults. This would have the effect of underestimating the true level of physical stress
imposed during exercise testing and the appropriate intensity of prescribed exercise programs.
(J Am Coll Cardiol 2001;37:153– 6) © 2001 by the American College of Cardiology

Maximal heart rate (HRmax) is one of the most commonly
used values in clinical medicine and physiology. For example,
a straight percentage of HRmax or a fixed percentage of
heart rate reserve (HRmax 2 heart rate at rest) is used as a
basis for prescribing exercise intensity in both rehabilitation
and disease prevention programs (1,2). Moreover, in some
clinical settings, exercise testing is terminated when subjects
reach an arbitrary percentage of their age-predicted maximal
heart rate (e.g., 85% of HRmax) (3). Maximal heart rate also
is widely used as a criterion for achieving peak exertion in
the determination of maximal aerobic capacity (1,4,5).
Because maximal exercise testing is not feasible in many
settings, HRmax is often estimated using the age-predicted
equation of 220 2 age. However, the validity of the
age-predicted HRmax equation has not been established,
particularly in a study sample that included an adequate
number of older adults (e.g., .60 years of age). The latter
limitation is crucial in that older adults demonstrate the
highest prevalence of cardiovascular and other chronic
diseases. As such, this is the most prevalent population
undergoing diagnostic exercise testing, representing a key
clinical target for exercise prescription. Importantly, older
adults are a population in which there is often a reluctance
or an inability to measure HRmax directly, owing to concerns
related to the physiologic stress imposed by strenuous
exercise. Thus, ironically, the 220 2 age HRmax prediction
equation is used in this population more than in any other.
Accordingly, the aim of the present study was to determine
an equation for predicting HRmax in healthy, nonmedicated
humans ranging widely in age. To address this
aim, we first used a meta-analytic approach in which group
mean HRmax values were obtained from the published data.
Subsequently, we cross-validated the newly derived equation
in a well-controlled, laboratory-based study. With each
approach, we attempted to establish the generalizability of
the equation by determining whether gender or habitual
physical activity status exerted a significant

 

[amirm]

They increase the rate and incline of the treadmill in an ECHO EKG in order to reach your desired heart rate for your age and yes they use 220 - your age

When I took the test, they asked me to keep running until I couldn't. I was ill and was a bit scared of passing out so I stopped just shy of what I could have done otherwise. To my surprise, they said my hear rate (?) was equiv. to a person 10 years younger! What did they compare it to? Is that some average they have on the same test? Or some other formula?

Interesting bit. The nurse said the above in a very positive manner. Then the cardiologist looked at it and barely acknowledged that it was better than the norm for my age!

 

[Speedskater]

Amir,
To my surprise, they said my hear rate (?) was equiv. to a person 10 years younger!
This is an almost meaningless statement. You can't compare one person's MHR to another person's. Sally Edwards tested triathletes that ran similar times and found that they had different MHR's.

Do a book search for:

Edmund R. Burke
Sally Edwards
Tim Noakes, MD

Your actual number is not important, it's how you exercise when you know the number.

 

[rbbert]

As Steve posted, medical stress tests using the Bruce protocol (pretty typical) still use the old 220-age formula for estimating MHR. It's for convenience and reproducibility as much as anything, I don't think anyone knowledgable about the subject thinks it's particularly accurate.

 

[MarinJim]

My goal in cardio (mountain biking on Mt. Tam) is to have fun.

 

[Frank750]

I just went through this at the University of Chicago Medical Center 2 weeks ago. A friend of mine and I do a Executive Health Care Physical every 2 years which includes a stress test. I was on the treadmill for exactly 12 minutes. My max heart rate was 182. My friend, and this was unbelievable to me because he doesn't do much exercise, was on it for 12:57 but his max heart rate was only 152. When doing this test, they make it clear that you are to go until total exhaustion. That's what I did. I don't think I could have gone 2 more seconds and she was about to bump the level up at 12:01 which would definitely have caused me a problem. This performance supposedly put me up in the 80th percentile for my age which is 59. My buddy was in the upper 90 percentile.

Based on the stress test results, a Physiologist then prepared a suggested cardio routine for me in a later meeting that day. When I questioned him on my friends ability to go an extra 57 seconds longer than I could, he explained that while it was great he could do that, my advantage was my max heart rate of 182 compared to his 152 gave me greater capacity for improvement. Still not sure about this but if he said it, it must be true??

Any way, I've been on an elliptical for the past week or so working my heart rate to 157 and trying to stay there for at least 30 minutes. I've been pretty good about it. After a month of this, I'd have to check the directions again to be exactly sure, I'm supposed to start interval training and take my heart rate to the max for a minute and then drop back down to 157 for a period then back up to 182 again for a minute. If anyone is interested in the specifics, I can give them when I get home.

Obviously this routine is customized by a Professional with direct and specific access to all of your medical records. I certainly wouldn't do any of this based on a formula around age and percentages.

 

[Mike]

Interesting methods in that article. I would not have thought that maximum heart rate to be a normally distributed random variable, but there wasn't any mention of transforming it using a natural logarithm prior to using a regression analysis. I didn't see p-values, either. I'll look again.

 

[Kingsrule]

They increase the rate and incline of the treadmill in an ECHO EKG in order to reach your desired heart rate for your age and yes they use 220 - your age

Not really
I just had one and my target was lower than 220- age by 30......
The one I had 3 years ago also used the same target rate as the one above.