T Nation

heart rates during cardio

how accurate are the heart rate meters on your average top notch gym equipment? after about 3 minutes of peadaling hard during a cardio workout i can move my heart rate to 170 on these machines. if i start doing serious sprints after that my heart rate goes up to 189. however, if i grip the posts hard as opposed to lightly it drops significantly to 170 or so…

how do i know if i’m over doing it? i never feel faint, dizzy, short of breath… i do feel worked out but the heart monitor sometimes scares me.

Good way to check is compare with a polar type chest strap device (usually pretty solid) or do a 6 sec pulse check to see if it is the right range.
After working in many gyms, you get to see some are good some are crap even ones that are the same model.
Also some get interference from the machines next to it, so if granny next to your is criusing your read out may be down and vica verca…

They’re probably bull. Once I compared with an actual rate monitor and it was off by 30bpm. Now I just bike till I start sweating hard.

-Zulu

Apart from the accuracy of HR montitors on fitness equipment, I recommend conducting your cardio based on your perceived exertion, not your heart rate. APMHR is an estimate only, and not a very good one for a lot of people. Also, HR response to exercise is not even close to the same for every individual.

Joel

I am posting a FAQ from Clarence Bass’s website about heart rate training. Enjoy:

Forget the Maximum Heart Rate Formula

Q: Do you use the standard formula for computing maximum heart rate (220 minus age) in designing your own training programs or programs for other people?

A: No. I?ve long suspected that the much-used formula is of little use, especially for athletes. I stopped using it when I discovered that my heart rate was not falling with age, as the formula predicts. My maximum has not fallen in more than 20 years. It was 182 when I was tested the first time as I approached 40, and recent tests at the Cooper Clinic showed that it?s still in that range or higher now that I?m over 60. (For further details on my heart rate maximum over the years, see The Lean Advantage 3.)

So, you can understand my interest when Vic Mansfield, a regular visitor to our site, called my attention to an article by Gina Kolata on last week?s The New York Times Health Page (April 24, 2001): “Maximum Heart Rate Theory Is Challenged.” It appears that I?m not alone in my rejection of “The Formula.” Believe it or not, the doctor who created the formula shares my skepticism.

The formula was devised in 1970 by Dr. William Haskell. According to the article, Dr. Haskell and his mentor, Dr. Samuel Fox, were trying to determine a safe level of exertion for heart disease patients. They culled data from about 10 studies and came up with the formula more or less off the cuff. Haskell, who is now a professor of medicine at Stanford, says the subjects in the studies were never meant to be a representative sample of the general population; most were under 55 and some were smokers or had heart disease. Nevertheless, “The formula quickly entered the medical literature,” The Times reports. “The absolute numbers took on an air of received wisdom.”

“I?ve kind of laughed about it over the years,” Dr. Haskell told Kolata. “[The formula] was never supposed to be an absolute guide to rule people?s training.”

Those in the know, so to speak, have long realized that the formula is only a rough estimate, and not a very good one at that. Dr. Fritz Hagerman, an exercise physiologist at Ohio University, told The Times that he learned from more than three decades of studying world-class rowers that the whole idea of a formula to predict an individual?s maximum heart rate was ludicrous. Hagerman has seen Olympic rowers in their 20s with maximum heart rates of 220. And he has seen others on the same team and with the same ability, with maximum rates of just 160. The reason, Hagerman explained, is that some athletes push out more blood with each heart beat, and others accomplish the same thing with a faster heart beat.

What guidelines should athletes use? The article doesn?t say, but I have some suggestions. First, you can have your maximum heart rate measured in an exercise physiology laboratory. As readers know, I?ve had mine measured at the Lovelace Medical Center in Albuquerque, the human performance laboratory at the University of New Mexico and at the Cooper Clinic. Once you know your actual maximum, heart rate is a pretty good indication of workout intensity and useful in comparing one aerobic workout with another. For more details, see the articles in The Lean Advantage 3 on my use of heart rate monitors.

Another approach is to use perceived rate of exertion, which is just about as good and certainly more convenient than monitoring heart rate. That?s the method I use most often in my hard aerobic workouts. Listen to your body and it will tell you how hard you?re working. There?s no need to focus on your heart rate. Your breathing and your muscles will tell you all you need to know. With a little experience, you can judge whether you?re working “very hard” or “hardly working,” or somewhere in between the two extremes.

I don?t need a heart rate monitor to tell me that I?m working extremely hard during my treadmill workouts. I record the time, speed and angle of incline in my training dairy and use that to judge my progress from one treadmill workout to the next. I do essentially the same on my rowing and Air-Dyne workouts, using the performance monitors on these machines to track my efforts. For specific examples of progressively more intense aerobic workouts, see Lean for Life. The key is to slowly ratchet up the intensity as your condition improves.

Best of Luck.