T Nation

resting heart rate effect on RMR

would a low resting heart rate (48-50) have an effect on Resting Metabolic Rate?

my resting heart rate is 48-50, but it sees my RMR is also very low? I need to get it tested, any suggestions for testing RMR?

is there a link between the two?

Scratch, take a look at the BodyGem/MedGem at healthetech.com. You can get your RMR tested. It’s a very accurate test, within 1-2%. There’s a locator, too, at that site that will find the closest location to you. I’d recommend you call everyone in the area. Prices ranged from $50 to $200 for the same test.



I don’t believe there’s a correlation between the RHR and RMR, though I’ll defer to someone who is stronger in exercise physiology than myself. The test is based on how much oxygen your body utilizes (which is affected by the amount of muscle you have), not how efficiently your heart pumps the blood to the rest of the body. If you don’t get a response here, you can always talk to the people at healthetech.com.



Good luck!!! I found the test provided me VERY useful information, and I consider it to be well worth the price.

Scratch…In addition to checking up on that useful info that TT provided, if you live near a large University, you might also inquire within to see if they offer services for measuring BMR/RMR. As far as any correlation between RHR and RMR, I’m not certain of anything in particular, but I’ll be glad to look into it.

TT…How did the actual results from the BodyGem compare to estimates for RMR, such as the equation used by John Berardi (i.e. 500 + 22 x FFM in kg) or the Harris-Benedict estimate (i.e. Timbo not sure:-)?

Pretty soon, they’ll be available at every 24-hour fitness.

Joel

It shouldn’t make a difference. Aside from that, if you live in the California Bay Area, I can test you as I do RMR tests and energy expenditure consultations.

Timbo, I never ran JB’s calculations for maintenance calories or diet-down calories. Even on RMR, I’m not sure what percentage of maintenance that number is. The guy that did my test told me it was roughly 80% of a sendentary person’s maintenance calories. And that’s how I use the number. I eat the number of calories reported as my RMR.



Joel Marion, however, has said that RMR is more like 60% of your maintenance calories, which would be way too much of a caloric deficit. Either way, I’m making progress, 'bout a pound a week.

For a normal, healthy, person

RMR- 60%

cost of activity- 30%

TEF- 10%

This is not taking into consideration any exercise performed, etc. For people on this site who exercise reguarly, the cost of activity percentage will go up.

Here are the variables that I have read about, and consider primarily affect BMR: [br]

Age: In young people, the BMR is higher; age brings less lean body mass and slows the BMR. [br]

Height: Tall, thin people have higher BMR’s. [br]

Growth: Children and pregnant women (and I would suspect training individuals in a constant anabolic state) have higher BMR’s.[br]

Body Composition: The more lean tissue, the higher the BMR. The more fat tissue, the lower the BMR. [br]

Fever [br]

Stress: Stress hormones raise the BMR.[br]

Environmental Temperature: Both the heat and cold raise the BMR. [br]

Fasting/Starvation: Fasting/starvation hormones lower the BMR. [br]

Malnutrition: Malnutrition lowers the BMR. [br]

Thyroxin: The thyroid hormone thyroxin is a key BMR regulator; the more thyroxin produced, the higher the BMR. [br]

As far as the heart rate goes, it may have a MINOR correlation, in the aspects of more EFFICIENT blood pumping, and therefore less energy utilised by the heart. So lower RHR = lower BMR?? No, I don’t think so.[br]
The heart is a VERY EFFICIENT ORGAN ANYWAY, only using a relatively small amount of energy/time.[br]
In comparison to ALL the above situations, it probably pales into significance. [br]

Can’t help on the testing front I’m afraid, but it looks like you got plenty advice there anyway. SRS

thanks guys will follow up on all the helpfull advice. i am in NY, but traveling this week to LA.

really appreciate the help.

In the resting state the body utilizes fat as its major fuel source. This fact provides a means to measure RMR. You see, one of the by products of the breakdown of fat is CO2. Therefore the ratio of 02 intake and CO2 release is the determinate of RMR. Your low heart rate suggest only that your body is more efficient at utilizing the oxygen you take in. RMR and BMR are generally increased with increases in lean body mass, unless you have a thyroid problem. If you have no reason to believe you have a thyroid problem (ie. family history, previous problems, anabolics) you should not be worried. You may still want to get it checked. If you live near a University contact the Exercise Science or Physiology department and you can often get it check for much cheaper than you can elsewhere, such as at a hospital. Some GA’s will even do it for free.