Target Heart Rates

January 20, 2005 8:19 AM

Target Heart Rate. What damage are you doing, if any, by working out above your so-called Target Heart Rate? [mi]

I have just returned to the gym after a 3+ years hiatus and whenever I track my heart rate, I am above the suggested zone. I feel fine when I am working out and have tried to increase resistence and/or slow down but nothing seems to help. I am a 29 year old female 25-30 lbs overweight.

posted by Lola_G to health (16 comments total)

Which zone are you targetting? If you're targeting aerobic and sitting in the anaerobic zone, you're not doing any harm, but you may not get the results you're looking for.
posted by teg at 8:48 AM on January 20, 2005

Decrease resistance?

Anyway, I'm not going to give you tons of links to exercise physiology sites. The Target Heart Rate that you get from gripping the shiny metal conductors (on a Precor EFX elliptical machine, for example) and entering some data like age and weight is not all that accurate. They are based on averages.

There are several formulas for determining your theoretical maximum heart rate. From there you can derive the low and high limits for a range that you might want to stay in while you exercise.

If you know your theoretical max you can then derive the 60%/70%/80% that put you in the "fat burning" or "cardio conditioning" range. If you really want to track heart rate, an inexpensive chest strap type monitor might be a good investment. Many machines will read the data from the chest strap transmitter (i.e. you won't need to wear the watch/receiver) and display the results.

Short answer: If you are in otherwise good health, no damage working above your 'target.' You are just working harder and deriving more benefit. Of course, I am not a physician.
posted by fixedgear at 8:51 AM on January 20, 2005

I do use the Precor EFX machine. I can't do the "fat burning" programs as I get bored too easily. I increase resistence in an effort to slow my self down but I am still above the so-called "cardio" zone.

I am just worried that I am working out ineffectively.
posted by Lola_G at 9:18 AM on January 20, 2005

The age-based Target Heart Rate computation is just an estimate... don't take it any more seriously than the Body Mass Index (which you shouldn't take very seriously.)

For a better test, you'd need to measure your Maximum Heart Rate with a treadmill test. And even then, percentages of that to get your aerobic vs. anaerobic zone would still be an estimate based on averages. In particular, people in very good shape often have a maximum heart rate (and thus aerobic target heart rate) way above the normal calculation.

Generally, anything you can maintain comfortably (you're not gasping; you could still speak) for a sustained period is going to be aerobic.


Zed, ACE-certified group exercise instructor and personal trainer
posted by Zed_Lopez at 9:30 AM on January 20, 2005

fixedgear: Is there an "inexpensive chest strap type monitor" and/or "chest strap transmitter" that you could recommend? I'd like to track my heart rate as I exercise and I don't need anything terribly fancy (though I wouldn't want it to fall apart after a couple months either).
posted by Alex Handcoding at 9:58 AM on January 20, 2005

The charts you see at the gym are not terribly accurate. After one of my spin instructors (who is also a paramedic) explained the origin of the charts I quit worrying about it so much.

I do have a heart rate monitor and love it, but I also go by how I feel and how my breathing is. All my life I have been above the charts...your true maximum heartrate is what your heart can actually do, not what the chart says. Having said that, you don't want to do your workout that high. Building a base of fitness at a lower percentage is much better, with lesser amounts of the high stuff.

Bottom line is, make sure you are breathing. Your body will let you know way before you do too much.

Alex H, I use a Polar model which cost around fifty bucks. It's fairly basic. I think there are cheaper ones but this one is holding up really well and I like it.
posted by konolia at 10:16 AM on January 20, 2005

These articles might be a bit more than what you're looking for but they offer some good advice on using your heart-rate to determine the relative intensity of your workouts: 1, 2.
posted by driveler at 10:30 AM on January 20, 2005

I read somewhere once that Jean Claude Van Damme increases his heart rate to 200bpm for an hour daily on a bike. Whoa. I think the article referred to this as a "controversial" fitness method.
posted by Shane at 10:44 AM on January 20, 2005

Alex, I got a prospritit heart-rate monitor at Target a few years ago for $30 and I've entirely satisfied with it. I've used it near daily for hour-long workouts and haven't had a problem.
posted by ttrendel at 11:03 AM on January 20, 2005

I've recently gotten into triathlon training, and read some books. So that doesn't make me an expert. FWIW, there are basically two zones worth working out in: aerobic and anaerobic. The main difference between the two is what the body uses as its energy source. In all cases, the body uses fat storage and carbohydrates as fuel. When operating in the aerobic zone, the mixture is more fat than carbs. As you progress through the aerobic zone into the anaerobic zone, (harder to maintain a conversation) the mixture swings to more carbs and less fat. There are other things that go on in the anaerobic zone (lactic acid, etc), but my point is to burn fat, stay in your aerobic zone while working out. You'll last longer and won't get as sore.

Complete a threshold test as others have suggested, find your zone and enjoy working out. Keep in mind I only read the books. I am not trained in this whatsoever.
posted by RobbyB at 11:16 AM on January 20, 2005

The cool thing about getting a polar heart rate monitor is a lot of treadmills, ellipticals, stairmasters and whatnots can read the sensors on your chest so you can see your HR without having to look at the watch.

I've been happy with my Polar monitor for years.
posted by birdherder at 11:35 AM on January 20, 2005

Is it universal that, if you feel ok, the heart rate isn't a big deal? I've been running for years without paying any attention to my heart rate. A couple of weeks ago, after finishing a 7-mile run on a treadmill, I grabbed the HR sensors on a whim and saw that I was in the 170s range... that sort of freaked me out, even though I presumably have been doing the same thing for a long time. Should I have been freaked out?
posted by COBRA! at 11:44 AM on January 20, 2005

I find the same thing (really high HR) whenever I haven't been going to the gym regularly. It normally starts falling down to more expected levels after a few weeks (or months, if the break was *really* long), once my heart gets more efficient at pumping.

One thing that I've noticed to speed up the acclimation process is interval training. Go fast, go slow, go fast, repeat. It seems to get my HR recovery times (that is, from the 170s to the 130s) down, fast.
posted by occhiblu at 1:11 PM on January 20, 2005

Yes, I second (third?) the recommendation for a Polar. Check out bike sites like Nashbar. That is a thirty buck HRM, will last a good long time, and work with the machines at most gyms. Substitute the word "person" for "cyclist" and you are all set.
posted by fixedgear at 4:03 PM on January 20, 2005

I only pay attention to my heart rate as a novelty. If you work out at a high heart rate, you'll get tired faster, but pushing your heart rate in spikes can improve your performance by improving your VO2 max (which I don't feel like explaining but google can surely tell you all about). Interval training is great for this.
I would worry about heart rate last, especially if you're just training to lose weight and not for some sort of competition. Go by your perceived exertion, not by some heart rate formula.
The aerobic/anaerobic zone thing is one of those fitness ideas that magazines like to bash all the time. Their point is (rightly) you burn more calories the harder you're working, and while the mix might be slightly more from fat at lower heart rates, ultimately you should care more about total calories burned, so ignore the "fat burning" vs "cardio" zones.
posted by ch1x0r at 4:43 PM on January 20, 2005

3 things:

-Without knowing your maximum HR, knowing your HR at anyone moment means not very much at all. A HR of 170 may be very high for someone with a max HR of 180, and may be midrange for someone with a max of 205.

-Most gym charts etc suggest HR zones that are too low because they do not factor in what is known as the HR Reserve. This is your resting HR. To find zones that are valid for you, take your MaxHR and subtract your resting HR (a HR taken after lying still for at least 20 min). Figure percentage zones on that number, and then add back in your resting HR. This is called the Karvonen method and is described here.

-The so called fat burning zone is a myth. This is because although you use a greater percentage of fat calories to fuel your exercise at a lower HR, you use a higher number of calories at a higher HR. Even though the higher HR uses a lower percentage of fat calories, it ends up using more fat calories as a concrete number because of the greater number of calories burned over all. This is explained here.
However, there is a reason to work out at a low HR, and that is in order to build a solid aerobic base from which to specialize your fitness. See this thread for information about effective training for fitness, which is, of course, different than simply losing weight.
posted by OmieWise at 7:57 AM on January 21, 2005