heart monitor

[veruca salt]

Hello, I was just wondering if anyone out there uses a heart monitor, and what one they used. I don't know how important it is, so I thought I would check with you first. Any information would be appreciated. Thank you.
Kerri

 

[Aquajock]

Hi, Kerri! IMHO a heart rate monitor is of limited value to a consistent exerciser, given that it only (I think) measures heart rate alone and does not measure stroke volume (i.e. the amount of circulatory blood being pumped out with each beat) which truly determines cardiac output. Because many things can affect heart rate that have nothing to do with how hard the person is exerting herself (climatic conditions including heat, humidity and elevation, caffeine or other stimulant intake, medications that can blunt or elevate the heart rate response, one's own cardiovascular fitness level), heart rates and their monitors must be taken in context. To truly determine cardio exercise intensity, an HRM might be of some value when combined with the Rating of Perceived Exertion and/or the Talk Test.

A-jock

 

[Aquajock]

P.S. Love your screen name. Roald Dahl would be proud!



A-jock

 

[trevor]

Hey there A-jock,
I may not have this right but I think heart rate is, at least indirectly, a measure of how much blood your heart is throwing out on each stroke. The more efficiently your heart pumps out blood, the less hard it has to work to accomplish this feat. Thusly, it will have to pump less times to get the job done, if this makes any sense. This is why a lower resting heart rate is desirable. I do agree that other outside factors like caffeine definitely affect this measurement but that's why you take baseline numbers during your resting state. Having said this I am not an owner of an HRM but I do think that they are a very valuable tool for measuring fitness and also measuring how hard you are working. I personally don't think much of "perceived exertion" measurements because there are days when you feel like hell during a workout but actually you aren't doing anything as far as challenging yourself cardiovascularly.
Anyway, just my two cents.

 

[Aquajock]

Trevor - your point is well taken. Again, it is the calculation of heart rate (the number of beats within a given time frame) combined with the volume of blood being pumped out with each beat (stroke volume) that gives you total cardiac output, the amount of oxygen-rich blood going out to the working muscles. And yes, the more efficient your heart is the fewer times it needs to beat; one of the benefits of effective cardiovascular exercise is a lower resting heart rate.

IMHO, if a heart rate monitor is to be used one should determine one's heart rate training zone by the Karvonen formula, which factor's in one's resting heart rate and thus one's current cardiovascular fitness level. And again, one should use the HRM in concert with other measurements: The Talk Test (you should be somewhat breathless and able to carry on a very short conversation, but NOT able to sing) and the Rating of Perceived Exertion. Especially in the summertime, with higher ambient temperatures AND higher humidity in many areas, the heart rate can be driven up in a manner that does not indicate true exercise-induced cardiovascular workload.

A-jock

 

[trevor]

Good points Annette. I too use the Karvonen formula. Maybe I will get a HRM one day, don't know yet. My spin instructor thinks they are a must for the class. Right now my HRM is my finger on the carotid!
Take care.