Practice a Healthy Way of Life

Heart rate is a useful indicator of fitness (resting heart rate), and work intensity during aerobic/cardio workouts, but it can be difficult to find and maintain a sense of your pulse manually when resting, and doing so during workouts can be difficult because you may be distracted by what you are doing or because taking your pulse may take your focus off your exercise. That’s why some runners actually walk for a short distance while they take their pulse manually, while bicyclists either stop or coast with only one hand on the bars.

The solution is a heart rate monitor. The most reliable ones are those that sense the heart rate through a chest strap.  I have been using one to track my workouts for some time, and I recommend them. Whether you’re really trying to get into optimal condition for some reason, or just trying to get in better shape than you are, a heart rate monitor can be like a coach, providing instantaneous (right now) feedback on your exercise intensity that can tell you when you need to ramp it down a bit or when you need to get your butt in gear. There is an adage I’ve heard in the fitness field that says “people tend to work too hard on their easy days and too easy on their hard days.”  I didn’t realize how true this was until I started using a heart rate monitor, and from personal experience I can say that a heart rate monitor can help you remedy this, so you can achieve your fitness goals more efficiently and avoid overtraining.

So, what can you do with a heart rate monitor (HRM)?

The HRM as Fitness Indicator

There are at least two heart rate parameters that are useful indicators of aerobic fitness, resting heart rate, and heart rate recovery. Resting heart rate is the lowest number of beats per minute (BPM) your heart reaches when you are fully at rest. Heart rate recovery is the BPM decrease in heart rate during a short period of rest after right at the end of a workout.

Resting Heart Rate. Measuring your resting heart rate is fairly easy. For the best results, you should pick a morning after a day or two in which you have not exercises extensively, because your heart rate will remain somewhat elevated for a day or more after a good workout. When you wake up, relax your body and either take your pulse manually (for 15 seconds and multiply by 4, 30 and multiply by 2, or a full minute), or hold your heart rate sensor across your chest and use your heart rate monitor to monitor your heart rate for a minute while you remain relaxed. If you use the recording function on your heart rate monitor, it may provide you an average heart rate during the minute and make things easier for you.  Just settle down and rest a bit before you start monitoring and stay still and relaxed during the process and you’ll get something approaching your true resting heart rate if all goes well.

Here’s a way to interpret your fitness based on resting heart rate:

Note: Don’t be alarmed (or overly excited) if these tables suggest you are more or less fit than you think you really are.  It’s really only a rough guide.

Heart Rate Recovery. I use a procedure that measures how much the heart rate decreases after two minutes of rest from submaximal exercise.  By submaximal, I mean that my intensity is elevated to a level I can maintain for a long period of time. That equates to around 65-75% of my maximum heart rate (more on maximum heart rate below), but as long as your are consistent each time you test, you can simply shoot for heart rates beetween 120 and 135 – a range that is squarely ‘aerobic’ for most people. You need to elevate your heart rate enough that you have sufficient room between your workout heart rate and your resting heart rate, to actually have a real “recovery.”

At the end of a typical aerobic (base training) workout, simply stop, lay down, relax completely, marking your heart rate at the time you stopped and then again after two minutes of rest. Some heart rate monitors will do this automatically when you stop your monitor’s chronograph/stopwatch function, which is convenient. It is best, if you can, to actually record the average heart rate for a short period at the end of the two minute period before you get up and start moving around.  An average is generally preferrable to an instantaneous reading in all circumstances because heart rate tends to jump around a bit.

The better your cardiovascular health and fitness, the more quickly your heart rate returns to normal after exercise. Research has shown that heart rate recovery after exercises is negatively correlated with risk of death due to cardiovascular disease. That means, the more your heart rate drops in the short period immediately following exercise, the lower your risk of heart disease.

Here’s a way to intepret your heart rate recovery in a 2 minute recovery test:

decrease in BPM / Fitness / Health Risk
less than 30 / Fitness: LOW / Risk: HIGHER
30 – 45 / Fitness: NORMAL / Risk: AVERAGE
more than 45 / Fitness: HIGH / Risk: LOWER

The HRM as Training Tool

An HRM is a great training tool, which can provide nearly instantaneous objective feedback on your exercise intensity during workouts, so you can adjust your effort appropriately for maximum benefit. For example, on days when you are planning to do aerobic or base training, you can use it to make sure your intensity is at aerobic levels. Since it seems to be natural for some people to always push their effort, it is not uncommon for people to routinely train at higher than squarely aerobic intensities, but if you are working too high, your muscles begin to switch over to anaerobic metabolic pathways, which cannot be used as effectively for sustained activity. One effect of working at these higher intensities during long workouts is that your muscles may adapt to working at higher intensity for a bit longer, which isn’t altogether unhelpful. However, the higher intensity also produces byproducts and tissue stress and microtears that slows recovery between workouts by forcing the body to divert energy it might otherwise use to build your aerobic capacity up (improving your endurance and ability to take up and use oxygen), to clear lactic acid and heal the muscle tissue. Likewise, if you are trying to push up your strength and edurance, you may want to work at higher than aerobic intensities. Feedback from an HRM can keep you in the right metabolic or heart rate “zone” (Heart Rate Zones are discussed below).

So, how do I use a heart rate monitor for training?

There are volumes describing heart rate training in all it’s variations. I base my own training on what I think is the simplest approach, called Heart Zones training (advocated by Sally Edwards), although I have adapted it to some extent for my purposes and incorporate other ideas that I think make sense. All of the approaches to heart rate training require some approximation of your maximum heart rate, which serves as the basis for determining your heart rate training zones. The zones are typically calculated as percent ranges of the maximum heart rate. For example, if :

Heart Zone – Percent of Maximum HR – Intensity
Zone 5 – 90-100% – MAXIMAL, anaerobic/difficult to sustain for long
Zone 4 – 80-90% – THRESHOLD, high-intensity, difficult, transitioning from aerobic to anaerobic
Zone 3 – 70-80% – AEROBIC, moderate intensity, sustainable for long periods
Zone 2 – 60-70% – LOW AEROBIC, light-moderate intensity, sustainable indefinitely, base endurance work
Zone 1 – 50-60% – MINIMAL/RECOVERY

Zone 1 is generally agreed to be the minimum intensity of exercises needed to see improvement in fitness and cardiovascular health. Zone 1 and lower Zone 2 are also often used for “recovery” work. During interval workouts, high intensity intervals are alternated with short recovery periods at Zone 1 or 2 intensity (more on interval training in another post), and on days between higher intensity workouts, people will sometimes do a very light recovery workout at these intensities.

Zones 2 and 3 are generally agreed to be best for building base aerobic endurance. If you want to be able to run for long periods to simply have the endurance to complete an endurance event, you should be doing a lot of work in the upper parts of Zone 2 and in Zone 3.

Zones 3 and 4 do the most to improve speed or performance in endurance events. Those who want to improve their times will include one workout during the week in which intervals are run in Zone 4 at the goal pace, alternating with Zone 1/2 recovery periods (more on interval training in another post). Some also include one “tempo” workout, or use tempo training instead of intervals. Tempo training involves starting at an aerobic pace after a warmup and gradually increasing the pace throughout the workout, finishing in Zone 4, sometimes sprinting in to Zone 5 at the end. Both interval and tempo training help increase the lactate threshold, the exercise intensity/heart rate at which lactic acid buildup rates exceed lactic acid clearance rates in the body, causing lactic acid to build up as muscles become exhausted. Some athletes (I am one of them), may run entire 5K or 10K races in Zone 4.

Zone 5 is reserved for high-intensity interval training and sprint training, because it corresponds to an intensity at which anaerobic metabolism dominates, lactic acid builds up, and fatigue sets in after a short period, forcing the athlete to stop. High intensity efforts in Zone 5 have their place, but if you want to build endurance, you will generally visit Zone 5 only rarely during your workouts.

So, how do I determine my maximum heart rate?

There are a variety of methods for estimating your current maximum “realized” heart rate.  If you are starting with low or poor fitness, you should recheck your maximum heart rate and adjust your heart rate zones periodically, because you may find that your maximum realized heart rate increases over time as you become more fit, and if you train seriously your maximum realized heart rate may eventually approach your maximum absolute heart rate. Maximum absolute heart rate is determined by genetics, but we have to improve our physiological and psychological (yes, some of it is mental) conditioning to ever approach it.  In any event, what you are interested in at any given time is the maximum realized heart rate, because it reflects the maximum you are capable of at any given time given your current condition.  Over time, as your maximum heart rate increases, you’ll find that it becomes easier to work in your existing heart rate training zones. By adjusting your zones periodically, you ensure that the perceived intensity required to work in each zone remains more consistent over time, and you’ll ensure that you are always “in the zone” you intend to be  in.

Calculating maximum heart rate. When you are just starting out with Heart Rate training, unless you already do the equivalent of running a 5K, you might as well start by calculating your theoretical maximum heart rate and using that to set your zones. Sally Edwards’ Heart Zones approach suggests the following calculations, but any number of other equations achieve similarly useful results (it’s just a number, after all – not magic):

Heart Zones® (Male) = (210 – (0.5 * Age) – (0.1 * Body Weight)) + 4
Heart Zones® (Female) = (210 – (0.5 * Age) – (0.1 * Body Weight)) + 0

Estimating maximum heart rate. There are a variety of tests you can do to estimate your current maximum heart rate that have worked out well for me. I use, and suggest, three methods and take the average of the two as my estimated maximum heart rate for calculating my heart rate training zones. One method is called the “step test” and if you do an internet search you will see that there are some variations on this test. I’ll explain how I do it here, which is consistent with the method suggested in Sally Edwards’ Heart Zones method. The second method is also suggested by Sally Edwards and it is called the “chair test.” The final method is the “5K race test.”

The Step Test goes like this:

1. Pick a step of about 8″ in height (a normal step in your house will do), but you can use a stepping block if you have one this size.
2. Step up and down on this step with both feet, switching your leading leg each time, so that each full cycle (up, up, down, down) takes 2 seconds – 30 cycles/second, for three minutes.
3. At the end of three minutes record your heart rate, round it up to the nearest 5 (this is my own modification), and add the appropriate constant to calculate your estimated maximum heart rate.

Constants depend on fitness level as follows (which you can judge based on your resting heart rate as described above).

Step Test Constants
Athlete: 65
Excellent: 60
Above Average: 55
Good: 50
Average: 45
Below Average: 40
Poor: 35

The Chair Test goes like this:

1. Sit down in a normal chair, then stand up and repeat full cycle (up, down) at a rate of 30 times per minute for one minute.
2. Record your heart rate at the end of the one minute, round up to the nearest 5, and add the appropriate constant to calculate your estimated maximum heart rate.

Constants depend on fitness level as follows (which you can judge based on your resting heart rate as described above).

Step Test Constants
Athlete: 80
Excellent: 75
Above Average: 70
Good: 65
Average: 60
Below Average: 55
Poor: 50

The 5K Race Test goes like this:

1. Run a 5K race, or just run a race-pace 5K distance course of your choosing.
2. In the last two minutes, really push yourself and sprint to to the finish.
3. Record your maximum heart rate at the end of the run and add 5 to it.

Observed Maximum Heart Rate. For people who include sprint periods or intervals in their workout regimen, maximum observed heart rate (MOHR) can be the best estimator of maximum heart rate, although I still at 5 to my MOHR to estimate my maximum heart rate.

Caveats

Maximum Heart Rate and therefore appropriate heart rate training zones, often vary for different types of activities (cycling, running, swimming, lawn mowing, whatever). Regardless, the estimates of maximum heart rate above will result in training zones that will be adequate to guide training in a variety of activities.  If you are a specialist, however, you may wish to have a sport-specific estimate of your maximum heart rate.  Cyclists can do a test similar to the 5K race test, but instead do it as a 10-15 min. time trial effort.  Start with 10-15 minutes of lite/moderate intensity riding (Zone 2/low 3), then drive as hard as you can sustain for 10-15 min, with a maximal effort sprint over the final 30-45 seconds. Add 5 to your maximum heart rate at the end of the ride, and you have your cycling specific estimate.

Final words (for now) on the subject

So, that’s it in a nutshell. You don’t absolutely need a heart rate monitor to train effectively, but if you want to train efficiently and shoot for your best performance, I suggest you give heart rate training a try.  Check out the Heart Zones methods by Sally Edwards, and check the resources available on the Heart Zones website to get some pre-designed workouts that use heart rate to guide effort for best results. It might seem intimidating at first, but a heart rate monitor might be the least expensive coach or personal trainer you will find, and it’s always a good idea to keep learning.

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