NOTE: This review is available as a downloadable MP-3 audio file (23 mB, 16-min, $1.99).

But, recently, new research has revealed other ways you can use your heart rate to determine not only how hard you are exercising, but, also how healthy your cardiovascular system is. This review will discuss 4 different ways you can use your heart rate to monitor your fitness. Your personal trainer may not even know some of these details.

1) MAXIMUM HEART RATE

Before you can calculate your training heart rate, you first need to determine your maximum heart rate.

a) In Non-Athletes:

The traditional formula for calculating maximum heart rate is:

• Max HR = 220 - age

However, several years ago, researchers in the department of kinesiology and applied physiology at the University of Colorado in Boulder noticed that this equation underestimated exercise heart rates in older subjects.

Hirofumi Tanaka, PhD, and his group conducted an exhaustive review of 351 studies involving nearly 19,000 subjects and derived a new formula. They then validated it in 514 healthy subjects.

They propose:

• Max HR = 208 - (age x 0.7)

In 40-year-old subjects, both formulas yield the same result (ie., 180 beats per minute). The Tanaka equation produces slightly lower limits (than the old one) in subjects younger than 40, and raises the limit slightly in subjects older than 40 years old.

Other formulas exist. However, Roy Benson, MPE, and Declan Connolly, PhD, authors of the excellent book Heart Rate Training, claim that these formulas are nearly worthless. They point out that the size of the heart in adults is variable and that this impacts on the maximum HR that can be achieved. Thus, they feel that the only precise method for determining maximum HR is with an "all-out" effort.

An all-out effort can be very risky in anyone other than an elite athlete. So, for that reason, using formulas that estimate maximum HR are the way to go.

But, let's say you're not interested in winning your age group in next month's neighborhood 10-K; you are only exercising for health reasons. In this case, you still need to know your maximum heart rate. Knowing your maximum HR allows you to determine your "training" heart rate, which is explained below.

There's also a medical use for knowing maximum heart rate. Cardiologists have determined that the inability to attain a target heart rate during exercise appears to be an ominous predictor of mortality. Researchers at the Cleveland Clinic found that patients who could not reach at least 85% of their predicted exercise heart rate had a higher risk of death (Lauer MS, et al. 1999).

b) In Athletes

As mentioned above, an "all-out" test is the most accurate way to determine maximum HR in an athlete. However, each athlete should be tested in an activity that most closely matches their chosen sport. Four of these methods are summarized below.

To get the most accurate HR reading, the final effort must be extremely intense. A HR monitor is highly recommended. (NOTE: Do not do this unless you are fit, or have been given a clean bill of health by your physician.)

• Runners, Basketball Players, Soccer Players, Tennis Players, Cross-Country Skiers:

The November 2004 issue of Runner's World magazine offers a method for fit runners to determine their maximum heart rate:

• warmup
• run as hard as you can for 3 minutes
• walk for 2 minutes
• run as hard as you can for another 3 minutes

During the last minute of running, you should be at your maximum heart rate.

Benson and Connolly, in Heart Rate Training, recommend this method in runners:

• Use a running track, or a gradual incline that goes for about 400-600 meters.
• Do a good 0.5 to 1-mile warm-up.
• Run 1 lap on the track, or, 1 lap up the incline as fast as you can.
• Allow 2 minutes to recover. Walk or jog during this period.
• Repeat the run test a 2nd time.
• Allow 2 minutes to recover. Walk or jog during this period.
• Repeat the run test a 3rd time. Assess your HR at the end of this run.

• Cyclists:

Benson and Connolly, in Heart Rate Training, recommend this method in cyclists:

• Find a route that requires a strong climb for 600-1,000 meters, and, a flat section that allows for a 2-to-3-mile recovery.
• Warm up by riding for 5 - 8 miles.
• Climb the hill as fast as you can. During the final 70 - 100 meters, get out of the saddle and push as hard as you can.
• Recover by riding on a flat section for 2 - 3 miles.
• Repeat the climb and recover again.
• Climb the hill a 3rd time and assess your HR.

• Swimmers:

Benson and Connolly, in Heart Rate Training, recommend this method in swimmers:

• Perform a 500-yd warm-up at a slow-to-moderate pace.
• Swim 100 yards as fast as you can.
• Rest 30 seconds.
• Repeat the 100 yard swim as fast as you can.
• Rest 30 seconds.
• Repeat the 100 yard swim as fast as you can and assess your HR.

• Rowers:

Benson and Connolly, in Heart Rate Training, are not quite as explicit for testing rowers as they are for other categories of athletes, but, it appears this may be the method:

• Warm-up by rowing for 15-minutes at a moderate pace.
• Perform an all-out 2000-meter effort and record your HR.

2) TRAINING HEART RATE

Now that you know your maximum heart rate, you can determine your training heart rate. Coaches and their athletes know that driving the heart rate up into a specific range is the key to improving performance in aerobic events like cycling, distance running, etc. For example, Ed Eyestone offers the following guidelines in the November 2004 issue of Runner's World magazine:

Serious endurance athletes (triathletes, distance runners, etc.) will train mostly at the aerobic training pace. About 10% of their training will be at the lactate threshold pace. Extremely-intense "intervals" make up only a small percentage of the overall training plan.

Training heart rate is also helpful for people who want to exercise for health benefits. Research shows that untrained individuals will begin to improve their aerobic fitness when they exercise regularly at 50% of their maximum heart rate (Pollock ML, et al. 1998).

For example, for a 60-year-old person, the maximum heart rate (using the Tanaka equation) is 166. Fifty percent of that is 83 beats per minute. Thus, exercise does not need to be exhausting to achieve a health benefit.

Active.com has a nifty Target Heart Rate Calculator.

3) RECOVERY HEART RATE

"Recovery" heart rate is a determination of how long it takes your heart rate to return to normal after you stop exercising. This concept is mostly for people who are out of shape. Research shows that people with a slower recovery are at higher risk of sudden death than people who recover more quickly:

• Researchers at the Cleveland Clinic exercised patients on a treadmill, then measured their heart rate 1 minute after running stopped and compared it to their peak heart rate. The failure of heart rate to fall rapidly after exercise stopped was associated with increased overall mortality (Cole CR, et al. 1999).

• A similar result was seen in a study from France. Cardiologists exercised patients on a stationary bike for 10 minutes, then measured their heart rate 1 minute after cycling stopped and compared it to their peak heart rate. Patients with the poorest recovery had 2.1 times the risk of sudden death compared to patients with the best recovery (Jouven X, et al. 2005).

4) RESTING HEART RATE

Last but not least, the 4th way you can use your heart rate to monitor your exercise program is to simply take your pulse while at rest. Resting heart rate is an indication of your aerobic fitness, and, also, if you have recovered adequately from yesterday's training session.

One of the dramatic things that happens to your heart when you become aerobically fit is that your heart pumps more blood with each beat. This is known as "stroke volume." Since more blood is pumped with each beat, the heart doesn't need to beat as fast, so, resting heart rate is slower.

In one study of female runners, the resting heart rate directly related to how far the women ran per week (Williams PT. 1996):

A similar trend is seen in men (Kokkinos PF, et al. 1995):

You may have heard of marathon runners who have resting heart rates in the 50's, or, even in the 40's. Generally, this is a sign of a strong heart and a healthy vascular system. In the 1970's, the great tennis player Bjorn Borg was reported to have a resting HR in the high 30's. When cyclist Lance Armstrong was competing, it was reported his resting HR was 32-34. But, the lowest resting HR I have ever read about was documented in another professional cyclist: Miguel Indurain, 5-time winner of the Tour de France. He had a resting HR of 28 beats per minute! (source: Heart Rate Training, p. 30).

The opposite is also true. In one study of middle-age men with no evidence of cardiovascular disease, a resting heart rate of 75 beats per minute or higher had 3.5 times the risk of sudden death compared to men with resting heart rates of less than 60 (Jouven X, et al. 2005). Thus, resting HR is also a powerful indicator of the "health" of your cardiovascular system. In fact, it appears to be a better measure of risk of cardiovascular events than other indicators such as cholesterol levels (Blair SN. 2009).

SUMMARY

It turns out that something as simple as keeping track of your heart rate can tell you a lot about your health and fitness. Here's how to do it:

• Maximum Heart Rate: To repeat, do NOT do the running test unless you have a clean bill of health from your physician. Instead, use the formula by Tanaka et al. listed above.

• Training Heart Rate: If you simply want to exercise for health benefits, you only need to exercise at about 50-60% of your maximum heart rate. However, if you want to improve your times in a 10-K race for example, then you need to push your HR into the 70-90% range periodically. Since it is very difficult to take your pulse when you are exercising this hard, use a heart rate monitor.

• Recovery Heart Rate: Most research studies have evaluated recovery heart rates at 60 seconds after exercise ends. A slower recovery back to baseline heart rate signals an unhealthy or unfit cardiovascular system.

• Resting Heart Rate: Take your pulse as soon as you wake up in the morning, preferably, without an alarm clock, and definitely before that first cup of coffee. Take it while you are still lying in bed; don't sit up. If you don't want to do a 60-second count, then do a 6-second count and simply add a zero.

FOR MORE INFORMATION

The definitive book on how to use your exercise heart rate to optimize your training is Heart Rate Training by Benson and Connolly.

Readers are referred to the following related stories in our Articles Library:

• Health and Fitness Targets
• Heart Rate Monitors
• Interval Training
• Measuring Fitness: Aerobic Capacity

EXPERT HEALTH and FITNESS COACHING

Stan Reents, PharmD, is available to speak on this and many other exercise-related topics. (Here is a downloadable recording of one of his Health Talks.) He also provides a one-on-one Health Coaching Service. Contact him through the Contact Us page.

REFERENCES

Blair SN. Physical inactivity: The greatest public health problem of the 21st century. Br J Sports Med 2009;43:1-2. (no abstract)

Cole C, Blackstone EH, Pashkow FJ, et al. Heart-rate recovery immediately after exercise as a predictor of mortality. N Engl J Med 1999;341:1351-1357. Abstract

Eyestone E. Heart-Rate Monitors. Runner's World, November 2004, p. 36. (no abstract)

Jouven X, Empana JP, Schwartz PJ, et al. Heart-rate profile during exercise as a predictor of sudden death. N Engl J Med 2005;352:1951-1958. Abstract

Kokkinos PF, Holland JC, Narayan P, et al. Miles run per week and high-density lipoprotein cholesterol levels in healthy, middle-aged men. Arch Intern Med 1995;155:415-420. Abstract

Lauer MS, Francis GS, Okin PM, et al. Impaired chronotropic response to exercise stress testing as a predictor of mortality. JAMA 1999;281;524-529. Abstract

Pollock ML, et al. American College of Sports Medicine Position Stand. The recommended quantity and quality of exercise for developing and maintaining cardiorespiratory and muscular fitness, and flexibility in healthy adults. Med Sci Sports Exerc 1998;30:975-991. Abstract

Tanaka H, Monahan KD, Seals DR. Age-predicted maximal heart rate revisited. J Am Coll Cardiol 2001;37:153-157. Abstract

Williams PT. High-density lipoprotein cholesterol and other risk factors for coronary heart disease in female runners. N Engl J Med 1996;334:1298-1303. Abstract

ABOUT THE AUTHOR

Stan Reents, PharmD, is a former healthcare professional. He is a member of the American College of Lifestyle Medicine (ACLM) and a member of the American College of Sports Medicine (ACSM). In the past, he has been certified as a Health Fitness Specialist by ACSM, as a Certified Health Coach by ACE, as a Personal Trainer by ACE, and as a tennis coach by USTA. He is the author of Sport and Exercise Pharmacology (published by Human Kinetics) and has written for Runner's World magazine, Senior Softball USA, Training and Conditioning and other fitness publications.