Heart Rate Training, again…
I know I have talked a lot about heart rate training in the past but I just wrote an article for USA Triathlon that was used in their coaches publication that pulls together all the information into one place. Here’s the article. Remember, it was written specifically for coaches but can be applied to anyone. This is a great time of year to get tested as the season is getting started so you can assess where you are and where you need to be. If you want to schedule an appointment for testing email me at info@annefinch.com or call FitMed Partners at 843.284.5720.
The Importance of Heart Rate Training
by Anne Finch, MS, CWC, USAT Coach
It is winter and most of your athletes are likely still in or starting to come out of base-training. By now you should have conveyed to them the importance of bringing down the intensity to allow their bodies to recover from the stresses of last season, to take the time to work on skills and limiters, and then start the process of allowing fitness to build again. Most coaches and athletes understand this in theory, but the hard work can be lost if proper heart rate zone training is not applied.
We know the purpose of training is to get stronger and faster week after week, year after year. Popular literature and well-respected endurance coaches often will refer to the concept of the fitness ceiling- that being the highest level of fitness that an athlete can currently achieve. Your job as a coach is to help your athlete hit that ceiling during the peak of his or her race year. The ultimate goal is to move your athlete beyond the current ceiling and improve year after year. What was once challenging can now be effortless.
But peak fitness can only be improved upon if your athlete has a strong base. When describing this to my athletes, I like to use a home-building analogy. The roof can only be as high as the foundation of the home can support. Without a rock-solid base building regime where one works on strength, endurance, and efficiency, the body will eventually break down and result in a decrease of the fitness ceiling.
This is why the importance of heart rate training should be clearly understood.
A heart rate monitor can be one of the most inexpensive and most worthwhile pieces of equipment an athlete can invest in, but it needs to be used correctly. Just wearing a heart rate monitor is not going to guarantee better training. Correct use of a heart rate monitor assumes two things. First, I recommend the athlete be tested to determine his or her exact heart rate zones. The default settings of the monitors use the Karvonen formula, a heart rate reserve formula, to determine these zones. Two athletes are rarely exactly alike, so understand that heart rates do not necessarily follow a formula or fit a standard mold either.
A VO2max test, the gold standard test for determining an athlete’s fitness level, is the ideal test for obtaining precise heart rate zones. If there are no facilities that perform VO2max testing in your area, you can perform a Conconi test to determine your athlete’s anaerobic threshold heart rate, and from the anaerobic threshold heart rate you can estimate aerobic threshold. While the Conconi test is preferred to the generic heart rate zones of the Karvonen formula, it is inferior to the VO2max test.
Once your athlete’s heart rate zones are determined the second assumption is that you and your athlete clearly understand the objectives of each and every training session and the importance of staying within the prescribed zones. Coaches may offer slightly different opinions on defining heart rate zones, but generally they are as follows:
- Zone 1 65% of Maximum Heart Rate (active recovery)
- Zone 2 65-72% of MHR (endurance)
- Zone 3 73-80% of MHR (high level aerobic)
- Zone 4 84-90% of MHR (lactate/anaerobic threshold)
- Zone 5 91-100% of MHR (anaerobic/race pace training)
During the off-season when recovery and building a strong base foundation are the main focus, the majority of training should be easy, sustainable efforts in heart rate zones 1 and 2. After several weeks less training time is spent in zone 1 and an increasing amount of time is spent in zone 2. Next, begin to introduce periods of training in zone 3. Then, once your athlete moves out of base building and into the fitness building periods you include harder efforts in zones 4 and 5. Without knowledge of the athlete’s heart rate tendencies and capabilities, this can easily become a guessing game and thus some precision in targeting ultimate fitness goals can be lost.
What happens to athletes who do not use a heart rate monitor or follow heart rate training can be seen in a 2001 study by Foster et al. They determined most non-professional endurance athletes tend to train too hard on easy days and not hard enough on hard days. As a result, you have an athlete training in what I call the Gray Area training zone. Within the gray area, an athlete is training too hard for improving his fitness foundation and not hard enough for maximizing the fitness ceiling. In other words, it is the place where there is minimal or unfortunately no reward for the effort.
Monitoring an athlete’s heart rate obviously provides data on how hard the cardiovascular system is working during training. But, there is more to it than that. It also serves as a gauge for what is happening in the body metabolically. The metabolic factor is critical for endurance athletes as heart rate is indicative of which energy system is being used.
There are three energy systems in the body – Aerobic (oxygen), Anaerobic (lactic acid), and ATP-PC – and each represents distinct metabolic events in the body. These metabolic events use different substrate as fuel – fat, carbohydrate, and phosphocreatine, respectively. There are advantages to training each of these systems throughout the year and important considerations should be made with each. Knowledge of an athlete’s heart rate zones will help you and your athlete pinpoint when he is using each of these energy systems.
The aerobic system is utilized within the low heart rate zones when the effort is minimal and oxygen uptake by the muscle cells is at its maximum. The primary fuel source used in these heart rate zones is fat. This is important to an endurance athlete for two reasons. First, fat is the most abundant fuel source in the body, even in the leanest athletes. In fact, if only using the body’s fat energy reserves, an athlete could exercise for close to 120 hours without refueling. Second, aerobic training provides an enhanced responsiveness to fat metabolism during exercise. Put another way, the more time spent training in the aerobic zones the more efficient an athlete becomes at metabolizing fat as the primary fuel source.
Once intensity increases to levels in which the oxygen uptake cannot meet energy demands, the body shifts to the anaerobic energy system. Training in this zone occurs once you have surpassed your anaerobic or lactate threshold heart rate. In this system the primary fuel source is carbohydrate. While carbohydrate serves as a quick and easy substrate, there are two key points to keep in mind when training or racing above the anaerobic threshold heart rate. First, a by-product of carbohydrate metabolism is lactic acid. While lactic acid is not problematic in itself, lactic acid metabolism produces lactate and hydrogen atoms. The hydrogen atoms cause acidosis in the body which may be responsible for the fatigue experienced with high intensity exercise. However, the body can be training to utilize lactic acid as a fuel source and thus threshold workouts are be vitally important to an athlete’s training plan. A second key point to remember about going above threshold is that there is only enough carbohydrate stored in the body to fuel a few hours of intense exercise. Once carbohydrate stores are depleted the athlete must slow down to utilize fat metabolism. Additionally, it may take anywhere from 24 to 48 hours to replenish carbohydrate stores after anaerobic training. Therefore, if another hard training session is performed before carbohydrate stores are replenished, further depletion can occur and eventually symptoms of over-training may occur.
The third system, the ATP-PC system, utilizes phosphocreatine to produce energy in very short bouts of extremely intense activity that last between 5 and 15 seconds. This explosive power is seen in all out sprints. To maximize the benefits of training this energy system, multiple intervals lasting less than 20 seconds followed by relatively longer recovery periods allows for high intensity training too brief to stimulate the anaerobic system. Intense interval training is useful in helping an athlete improve their peak oxygen consumption (VO2max). Use of a heart rate monitor for interval training will ensure that the athlete is producing absolute maximal efforts needed to see peak VO2 gains.
Understanding the three energy zones and comprehensive knowledge of your athlete’s heart rate zones-specifically their anaerobic threshold heart rate- will help you help them prevent gray area training. This ensures long-distance training sessions which are important for building or maintaining endurance and stay low enough to maximize fat metabolism. It also guarantees that shorter threshold and interval training sessions are intense enough to maximize their benefits as well.
Anne Ahern Finch, MS, CWC is owner of Anne Finch Endurance Training in Charleston, SC, as well as an Exercise Physiologist, an adjunct professor of Anatomy and Physiology, personal trainer, and competitive cyclist and triathlete. She can be reached at info@annefinch.com.
References:
Foster C, Heimann KM, Esten PL, Brice G, Porcari JP. Differences in perceptions of training by coaches and athletes. S Afr J Med 2001: 8: 3–7.
Hagerman, Fritz. Training the Energy Systems.
Filed under: Training | Leave a Comment
No Responses Yet to “Heart Rate Training, again…”