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by Kevin Polansky

April 4, 1993

Know the five heart rate zones

In my last article I stated that swimmers are learning from other aerobic-based sports about a new scientific breakthrough for more optimal training. By using a heart rate monitor, all swimmers can more easily determine their specific training level and consequently produce a desired level of physical fitness.

Having determined your resting heart rate (RHR) and your maximum heart rate (MHR), you can use a few simple calculations to determine your specific training level. Each level has its specific benefits. With the help of your coach, you can develop a training program oriented to your individual distance and stroke preferences.

As mentioned in Part I, the five levels of training specificity for swimming are:

  • Moderate to Easy: 50% to 60% of your MHR
  • Weight Management: 60% to 70% of your MHR
  • General Aerobic: 70% to 80% of your MHR
  • High Aerobic Threshold: 80% to 90% of your MHR
  • Anaerobic or Red-Line: over 90% of your MHR

Over the last twenty years, I have seen numerous training techniques and philosophies come and go . . . especially in Masters swimming. Since Masters swimming has little or no research to back our training philosophies, many of us have been training as we did while competing on the high school, club, or college levels. We often attempt to continue training with the same intensity that we exhibited in our younger days. Yet as we get older, we must take into account the aging process. Using a heart rate monitor will help us to train with better results and will keep us from "overtraining."

Yet how can we tell that overtraining is taking place? Very simple. Take your RHR every morning and look for significant changes. If your RHR has dropped from the initial monitoring, rest assured that you are getting stronger and swimming faster. If it has risen approximately five beats per minute above your initial RHR, you may be experiencing the following:

1. Overtraining or fatigue. It usually takes from 24 to 96 hours to recover fully from a workout depending on the swimmer's training levels and time spent in those levels. Obviously, a swimmer training for only 20 minutes at the Weight Management level will usually recover more quickly than a swimmer training 30 minutes at the High Aerobic Threshold level.

2. Health-related problems. Watch out for sickness, injury, fever, and other stress-related problems. While using my heart rate monitor in a workout this past winter, I noticed that my heart rate was unusually high for a normal warm up. I proceeded to have one of my worst workouts in months. Not only was I unable to swim for long, I was unable to swim very fast, and I quickly became frustrated. As expected, less than eight hours later I came down with a sore throat and fever which turned into strep throat.

To train more specifically to your optimal range, you must monitor your own heart rate rather than comparing your efforts with another. Resting heart rate values can vary as much as 50 to 60 beats per minute between two people of the same weight, height, age, and sex. Although you may be warming up at the same speed as your partner, you may be in the Easy to Moderate range (50% to 60% MHR) while your partner may be swimming at the High Anaerobic Threshold level (80% to 90% MHR).

So that you may better understand the five specific levels of training, here is a brief and simple explanation of each:

1. MODERATE TO EASY (50% to 60% of MHR)

This level of training may seem to be very easy and relaxed. That's because it is! Unfortunately, many swimmers believe the misperception that because we feel we are not working hard or breathing hard, there must not be any training benefits. Not true! Exercise physiologists, trainers, and coaches are using this level more and more due to its warm up and recovery effects.

Adults starting a training program should begin by swimming at this level. Experienced Masters should be using this level for warming up, cooling down, and for relaxed recovery swims between or after very high intensity swims (high aerobic threshold or red-line swimming). Generally, 10% to 15% of your training should be at this level.

2. WEIGHT MANAGEMENT (60% to 70% of MHR)

Research has shown that at this level, your body reaps the benefits of burning fat while improving on your aerobic fitness. Stroke drills and moderate-effort long swims with short rest periods are ideal for this level. Much of your base training in early season should fall in the Weight Management level.

A good indicator of training at 60% to 70% of MHR is in being able to talk with your coach immediately following your swim without having to catch your breath in mid-sentence. Roughly 20% to 45% of your training should fall in this zone, depending on the phase of your training season.

3. GENERAL AEROBIC (70% to 80% of MHR)

General Aerobic swimming is also known as endurance base training. At this level, your body produces lactic acid equal to your body's ability to remove it. Training in this zone will give you the benefits of becoming fitter, stronger, and faster. Roughly 40% to 50% of your training should be General Aerobic.

An example of a main set would be one in which your heart rate would decrease by 10% between repeats. Depending upon age and fitness level, this may be a rest of 10 to 60 seconds between repeats.


During this training zone, your body changes from aerobic training to anaerobic training. You will feel the pain of training hard and experience fatigue, tired muscles, and heavy breathing. Those who swim against the clock and are competitive with their fellow swimmers should train in this and the Red-Line zones.

During sets at your high aerobic threshold, you will need more rest to recover from each swim. Your work to rest ratio might be 2:1 or 1:1. You need not do much High Aerobic Threshold training at the beginning of your training season. Near the end of your season, you may wish to do as much as 30% of your workout in this and the Red-Line zone.


In order to become extremely fit and to prepare for racing, you must train in this zone. You will experience oxygen debt as your train your speed (fast-twitch) muscles for competition. You will feel the intense pain in your muscles as you give 100% effort.

Your work to rest ratio will be anywhere from 1:1 to 1:6, or even higher. Since the intensity is so great, you will be unable to maintain this speed for very long. Like the High Aerobic Threshold level, you will do very little of this training in early season and increase during tapering to roughly 30% of your total yardage, combined with the previous level.

My personal experience has shown that using a heart rate monitor enables me to get in better shape faster and with less fatigue than in years past. Who knows -- maybe it can do the same for you!

Kevin Polansky has coached high school swimming for twenty years and was named Colorado high school Coach-of- the-Year on four occasions. He holds eight Masters world records and ten national records. He ran the first Masters training camp at the US Olympic Training Center last summer.


  • Technique and Training
  • Health and Nutrition


  • Sports Medicine