Max Heart Rate, Testing, Zoning for Conditioning
Heart rate training is a very useful tool for make big gains in cardiovascular conditioning, provided it’s based on good effective estimations of what is appropriate intensity levels per the athlete/student. Max Heart Rate (MHR) can be measured accurately in the lab but is time consuming and fairly pricy. It is possible to estimate ones Max HR accurately via self testing using parameters like heart rate at lactate threshold (Carmichael, 2003) and this is used to set up heart rate based training zones. Recently, a newer, non-intrusive way to test this that may prove more accurate than for anyone at any age is Watts (Power). This is to say, it is easier to attain HR at Lactate Threshold (LT) without using a formula. A simple Functional Power Test correlated to HR will help greatly in setting appropriate HR Training zones.
LT power output levels appear to reflect the ability of Adenosine Triphosphate and Phosphocreatine (ATP-PCr) energy pathways to produce high powered energy. ATP is created and stored on the muscles cells as fuel. These cells then generate mechanical work (i.e. cycling, running, etc.) from the energy produced in a naturally occurring chemical reaction the converts ATP into Adenosine Di-phosphate (ADP) and phosphate (P). ATP is stored in limited supplies that are quickly consumed by the muscle cells during exercise. The body using an organic compound found in the muscle tissue called Phosphocreatine and the resulting ADP to re-synthesize ATP. The ATP-PCr energy pathway defines the energy created by the breakdown of PCr to a re-synthesized ATP (Fitness Advisor, 2008). At a certain load or intensity, the Lactate created or produced will out-way the removal and clearance. This is the Lactate Threshold barrier (the point of peak sustainable HR). As intensity (and HR) increase beyond this point (where removal is not capable to keep pace with production) an acidoses state appears to occur and systematically the body begins shut down in attempt to return to a more balanced homeostasis. The body protects itself from harm by slowing itself down.
Understanding the Lactate Threshold
Understanding the Lactate Threshold barrier and it’s associated HR is key for creating proper HR zone values and percentages for conditioning. Why are zones important? Well, simply put, there are different metabolic processes that occur in each zone. Conditioning each one of these zones is paramount for a good fitness plan. Understanding how and when to train these specific zones is also key. Especially, when considering high performance athletes or anyone who wants to truly maximize a workout.
There are several ways to test for aerobic and Lactate Threshold power values and correlate to it to heart rate, however, the most precise way is to do a full stress test (VO2 Max Test) in a lab on a bicycle or treadmill. Testing for LT Power outside of a lab is not very difficult but it does require some equipment such as a good bicycle or stationary bike and a power meter. Once your’ve figured out the LT Power Threshold and it’s associated heart rate, it’s not very difficult to set one’s zones based on percentages using LT as the lowest part of zone 5. For example with an LT of 175 (the beginning of zone 5) it’s safe to say that’s ruffly 85-90% of one’s Max. But really the limiting factor in all performance is the LT Barrier. So therefore, training to this (LT Barrier) becomes very important for increasing cardiovascular conditioning and ultimately performance. Max HR values are not a vital metric for training performance (however, it is important to know for overall fitness).
Based on research and applications of HR Max prediction, I recommend the following:
- Currently, there is no acceptable formula for accurately estimate HR Max
- Should you need or want to estimate Max HR, then population specific formulas could be used as guideline. The most accurate general equation appears to be that from Inbar (1994) which is HR Max= 205.8 – 0.685 (age). Nevertheless, the error margin is +/- 6.4 bpm (a fairly large margin).
- An acceptable prediction error for HR Max (see white paper), for application, is an estimation of VO2 Max which is +/- 3 bpm. Thus, a person with a HR Max of 200 bpm, equals and error of +/- 1.5%. If this precision is not possible, then there is no justification for using for using VO2 estimation.
- Additional research needs to develop to improve the accuracy of HR Max prediction for specific populations and modes of exercise. However, attaining Peak HR is easier to achieve though simple testing (i.e. the Pacer Test or step test or Functional Power Test (FPT)
- Current Functional Power Testing may be a more appropriate and accurate way to asses HR at LT to determine HR training zones that are appropriate for individualized zone conditioning plans
- Use a 5 zone training plan to get the most from your workouts and save time by optimizing what you do and when you do it. Get in, do your plan, get out! 🙂