It’s a well know fact that utilizing Heart Rate monitors within your training regimen is the best way to maximize the effectiveness of your training programs while minimizing your effort and time spent in workouts. Essentially, doing more with less. The effectiveness and accuracy of tools to monitor heart rate zones within workouts has grown by leaps and bounds over the past decade, as popularized by companies like Polar. The question then becomes, how do we utilize these tools to maximize training?
Traditional means of estimating maximum heart rate is the use of the simple equation: 220-age=Max HR. Other common equations include paced running tests, step tests, and walking formulas, along with a variety of others that are supposed to estimate Max HR, VO2 Max and Anaerobic Threshold. From these, athletes are told to estimate their training zones by taking percentages of these numbers (i.e. 70%, 85%, etc. depending upon the goals of that specific training session). Within these equations and numbers, one is expected to train three different energy systems, plan recovery workouts, and assess overtraining concerns.
If you have ever tried this, it proves to be very difficult with just an “estimate” of your training zones. This is due to several problems with traditional methods. None of the equation methods take into account the individual’s fitness level or their genetic potential. Most of the equations are also not individualized to each athlete, especially the 220-age equation. In fact, Dr. Haskell (the developer of the formula) was quoted in the New York Times, “The formula was never supposed to be an absolute guide to rule people’s training. But, it’s so typical of Americans to take an idea and extend it beyond what it was originally intended for.”
The other major problem with Max HR formulas and equations is that they rarely look at Anaerobic Threshold. Anaerobic Threshold is defined as the point at which the body’s metabolism changes from Aerobic to Anaerobic. This is associated with heavier breathing, increased fatigue, burning in the muscles, production of carbon dioxide and an increase in Lactic Acid production. For the endurance athlete, this point is very important, because pushing the body to the anaerobic energy system can quickly lead to a state of fatigue, and ultimately, a slower pace. Anaerobic Threshold is not only affected by age and genetics, but it is also rather dependent upon an individual’s training status.
In the past, the only means of determining an accurate Anaerobic Threshold has been through a very intense graded exercise test consisting of a dozen EKG leads, a nose plug, a large tube in the mouth and running or cycling until complete failure. Fortunately, over the past few years, technology has become such that testing and exercise prescription has become much easier and cheaper to perform. Units such as the Zephyr Technologies Team testing and monitoring system has proven to be a very valid and reliable means of performing a sub-max graded exercise test. The test usually lasts between eight and twelve minutes and consists of either running on a treadmill or riding your road bike while wearing a mask and Polar heart monitor. The test begins at a very low intensity exercise (i.e. walk) and increases in intensity every minute or so. The intensity continues to increase until the athlete is at approximately an 8 out of 10 on a perceived exertion scale (with 10 being the worst workout imaginable). At that point, the athlete should be long past their Anaerobic Threshold and approaching their maximum heart rate.
Throughout the test, heart rate, ventilation, skin temperature, activity level and power are all monitored. As demonstrated in Figure 1, the ventilation will rise at a constant rate for the first several minutes of low intensity exercise. The beauty of the system is that it monitors all of this without the use of a mask. As the intensity rises and the athlete approaches anaerobic threshold, a temporary decrease is usually seen in ventilation, followed by a sharp increase as the athlete begins to breathe harder and expel large amounts of carbon dioxide in an effort to decrease blood acid levels and return the blood stream to a natural pH level. The dip is the moment when the body moves from the aerobic energy system to the anaerobic system and is a very important moment for training purposes (marked in figure 1 by a vertical line). While the Zephyr also determines VO2 Max, recovery HR, Calories per minute, and fat percentage, the AT HR is by far the most important component of the test.
From the AT HR, accurate training zones can be determined. A great deal of different philosophies exist with regard to what training zones one should use. Most of them revolve around either a 5 or 3 zone program.
The major underlying concept behind any heart rate training program is variation among workouts. With the human body being very accommodating, it is important to constantly keep the body’s systems off balance to eliminate plateaus.
High intensity interval workouts are useful for increasing one’s Anaerobic Threshold (AT). By increasing the AT, an athlete will be able to compete at a higher level by increasing their intensity while staying Aerobic and thus preventing fatigue. Low intensity recovery workouts are important for allowing the body to repair damaged tissue caused by high intensity training. Medium intensity workouts usually consist of training at or just below the AT to allow the body to adapt to race day intensity.
Heart Rate training has proven itself to one of the most effective means of endurance training for its ease of use and effectiveness when proper testing is available.