Heart Rate Training

Training Intensity

Choosing the correct training intensity is key to developing the endurance to run a successful marathon. The emphasis here is on training intensity not training pace! The term intensity is simply a measurement of how hard you are working during an exercise.

A reliable measure for the intensity of your training is your heart rate. Your heart rate increases with increased training intensity. Your heart rate will e.g. also be higher if you attempt to train at the same pace but are still fatigued from a previous workout or a lingering illness.

Several factors determine your training intensity, e.g. of course the pace, your fitness level, the terrain you are running in, your daily form, the environmental conditions . E.g. your exercise becomes a lot more intense when you maintain a constant pace changing from running on a level surface up a steep hill.

A heart rate monitor is the tool of choice to accurately measure and monitor your heart rate during the workout. Most heart rate monitors today store the development of your heart rate for the duration of the workout and allow you to download and analyze it on a computer.

Train Smart not Hard

Training at a higher intensity does not necessarily yield a better result. The risk of injury increases significantly and over training can become a serious problem. Moreover training does not have the desired training effect. Training at a high intensity conditions so called fast twitch muscles which deliver the greater force required for the high intensity but cause early fatigue. All these effects might not show immediately but several weeks or months into the training!

Training at a intensity too low does not have the desired training effect either.

The choice of the correct training intensity is therefore essential to condition your slow twitch muscles needed for an endurance event.

Maximum Heart Rate (MHR)

Maximum Heart Rate is the heart rate at the point of highest workout intensity. The accurate maximum heart rate is measured under lab conditions in a fatigue or stress test and can only be attained for a very brief period. In the absense of a stress test running uphill to the point of exhaustion and taking the heart rate at the top approximates the maximum heart rate well. The often quoted rule of thumb, MHR = 220 - age is in my opinion not very accurate.

Training Zones

The maximum heart rate is used to determine the correct Target Heart Rate Zones for the specific types of exercise. The American College of Sports Medicine(ACSM) recommends a target zone of 60-80% of the maximum heart rate for exercise. A lower HR is recommended for endurance base training and weight loss, while the higher range is used to improve cardiovascular fitness and athletic performance. Exercise Intensity is typically measured in percent of your maximum heart rate.

We distinguish 5 heart rate zones for exercise intensity, numbered from 1 to 5. The heart rate zones are only a guideline.

• Zone 1 is the base training HR zone. Zone 1 is aerobic exercise used to increase endurance. The HR should be 60-65% of the MHR.
• Zone 2 is no-mans land. Training in zone 2 is too exhausting to improve endurance and not intense enough to yield the improvements of zone 3. Avoid training in zone 2.
• Zone 3 is the threshhold training HR zone. Hill training, tempo runs and interval training is run at this intensity. Zone 3 is used to increase cardiovascular fitness. The HR should be 75-85% of the MHR.
• Zone 4 training improves your body's ability to deal with training at an anaerobic intensity level. Track interval workouts and repeats are in this category, the HR is 90-95% of the MHR.
• Zone 5 is peak intensity exercise. If used carefully training in this zone can help to improve peak intensity the body can handle. The injury risk at this intensity is considerable. This exercise is done at 95%+ of the MHR.

Heart Rate and Fitness Levels

At the beginning of the training your heart rate will only allow you to train at a rather slow pace. Often, this is regarded as demoralising and consequently ignored. Zone 2 is then used without given any better training results at the end. Following the zone based training regime, your fitness level will improve within a few weeks and you will be able to run at a much faster pace while staying within the same training zone.

Moreover, as your body adapts your training zones shift. While 60-65% might be an accurate range for an aerobic workout at the beginning of the training, this may very well change to 65-80%, allowing you to run at an even faster pace for a zone 1 exercise.

Example: consider an experienced marathon runner with a MHR of 193 monitored for one year after a training interruption.

How to Find your Training Intensity?

Unfortunately, a lactate test is necessary to determine the exact heart rates defining the training zones. The heart rates given as guidelines are a good approximation for a fit distance runner. Many heart rate monitors have built-in algorithms to determine heart rate zones with a simplified stress test.

In the absence of a heart rate monitor we use your previous race performance to determine the appropriate pace group and your training intensity.