Sunday, July 28, 2013

Playing the Numbers: Heart Rate

Photo credit: FratmenJonah
I've really just begun to look at heart-rate training. I know I keep my body in my target heart rate, described below, but I've not begun to maximize my cycling efficiency with heart rate zones. That's the next step, and this preliminary outline is just the beginning. Use it to gain a general understanding of the topic. For a general discussion of this topic for cyclists, read here.

As a preface: just get out and bike. Any amount of doctor-approved aerobic exercise is more likely than not to be beneficial. That being said, you can maximize your workout and make it more safe by
knowing something about heart rate and its effects on exercise.

I. Simple: Resting and Target Heart Rates

The American Heart Association recommends these steps:

A. Determine your resting heart rate.

This you do in bed when you first wake up. You can follow the American Heart Association's instructions, or you can strap on your Garmin and use it to determine your heart rate at rest.

Resting heart rate is unique to each person, so you can't just go by a chart. The average is 60 to 80 beats per minute. Athletes typically have lower resting heart rates, which can be as low as 40. If you're just starting an exercise routine, your resting heart rate can be as high as 100. Your resting heart rate will also increase as you age, so you may have to repeat this step periodically.

This will establish a baseline and help you to determine if additional medical intervention is required before you start a new exercise program.

B. Know your target heart rate range.

For this step, you can use the age-based chart on the American Heart Association's website:


This step will be expanded in the intermediate step, below.

C. Monitor your exercise to make sure you're within your target range.

Then, as you exercise, monitor your heart rate. You can do this for free with a watch and your finger, but a much easier way is with your Garmin (or similar device). The point here is to keep your heart in the range indicated for your age.

I'm between 45 and 50, so my target heart rate is 88 to 149 beats per minute. This represents 50 to 85% of my maximum heart rate (estimated to be 175 beats per minute per this chart).

The point is to slow down if your heart rate goes over the maximum and to increase effort if your heart rate goes below the minimum. Start out slow and increase over time.
During the first few weeks of working out, aim for the lowest part of your target zone (50 percent). Then, gradually build up to the higher part (85 percent). After six months or more, you may be able to exercise comfortably at up to 85 percent of your maximum heart rate. But you don't have to exercise that hard to stay in shape.
Exercising in your target range will maximize fat burning and aerobic activity. You have to keep your heart rate up in the range from thirty minutes three times per week (for minimal results) up to at least one hour every day to achieve real weight loss.

II. Intermediate: Calculating your Maximum Heart Rate

Once you have a good handle on maintaining exercise in your target zone, you can fine-tune those numbers by calculating your personal maximum heart rate, rather than relying on the averages. There are several methods. I'll outline the first one here. Ride With GPS points to Sally Edwards's page on calculating heart rate, which is where I got this information.


The SubMax 1-Mile Walking Test.
Go to any high school or college track (most are 400 meters or 440 yards around) and walk or stride as fast as you can in your current condition. Walk as fast as is comfortable. Walk four continuous laps. 
The last lap is the important one. Take your pulse, or use your heart rate monitor, to determine your average heart rate for only the last lap. The first three laps are just to get you to reach a heart rate plateau and to stay there for the last lap. 
Add to this average last lap heart rate the one of the following that best matches your current fitness level: 
1. Poor Shape: +40 bpm 
2. Average Shape: +50 bpm 
3. Excellent Shape: +60 bpm
This final number (for example, an average 135 bpm last lap plus 60 bpm, because I'm in excellent shape, would equal 195 bpm for me) should be fairly close to your Max HR.

I haven't tried this yet. Anyone willing to do it with me?

III. Advanced: Training Zones

Since I've not even figured out my personal maximum heart rate, I can't say that I'm ready to talk about training zones with any authority. However, I'll lay them out here and leave it for future blog posts to discuss the details.

Basically, each "zone" is a subset of your target heart rate range, plus the range from 80 to 100%. A general description from Bike Radar is:


  • Zone 1 (60-65% of maximum heart rate): For long, easy rides, to improve the combustion and storage of fats.
  • Zone 2 (65-75% of MHR): The basic base training zone. Longish rides of medium stress.
  • Zone 3 (75-82% of MHR): For development of aerobic capacity and endurance with moderate volume at very controlled intensity.
  • Zone 4 (82-89% of MHR): For simulating pace when tapering for a race.
  • Zone 5 (89-94% of MHR): For raising anaerobic threshold. Good sessions for 10- and 25-mile time-trials.
  • Zone 6 (94-100% of MHR): For high-intensity interval training to increase maximum power and speed.

If you follow the AMA guidelines, you'll stay in Zones 1, 2, and 3 for your entire ride. As you can see, generally, this means burning fat and moderately intense exercise. For me, using 180 as my maximum heart rate, these zones are:

  • Zone 1: 108 to 117 bpm
  • Zone 2: 117 to 135 bpm
  • Zone 3: 135 to 147 bpm
  • Zone 4: 147 to 160 bpm
  • Zone 5: 160 to 169 bpm
  • Zone 6: 169 to 180 bpm

Now I know I ride over 147 bpm regularly. For my most recent 78 mile bike ride, I was in Zone 4 for only 11 minutes.


So, what are the advantages of training up to be in higher zones? Without reading more, I can say that training for higher zones increases your capacity to ride in them. This means that you can climb faster and more efficiently. Since climbing is my favorite part of cycling, I'm going to try to increase this number over time.

I'm also going to read more about how to do so, and will report what I learn here. Anyone want to go for a ride?

Love,
Your Bear

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