As of late, I have received numerous questions via email or phone regarding training zones, what zones mean, and how max HR is important to the success of zone calculation.
I want to explain exactly what max HR is, how it can be used, and how it can function to the benefit or detriment of your training.
First of all, max HR is defined by many-a-textbook as the maximum rate at which your heart can beat and still produce a suitable cardiovascular output. We have all been confronted with data from our various performance devices which tells us the maximal HR we achieved during a specific bout of exercise. Of course, with increasing intensity, the probability of achieving a “new max” (in parentheses for a reason…) becomes higher.
However, it is very interesting to note that this “new max” shouldn’t be considered a new max HR at all- it is only a new percentage of your theoretical max HR. We’ve all been inoculated with the ole’ “220-your age” idealistic metric towards zone calculation. What this naturally assumes is that, as you age, your natural (or theoretical max) decreases. This is simply not the case.
Now, your ability to achieve a certain level of max most certainly does, but this is only linked to the hormonal decline in an achievable level of fitness, which DOES decline with age, of course.
When using your max HR for zone calculation it is very important to take into consideration the time of year (proximity to key events), fitness status, and primary method of training. As you become more aerobically fit, your max HR increases due to the increased oxygen demand placed on your cardiovascular system via mitochondrial oxygen consumption (in the muscle).
This can be seen during near-max efforts such as what you might encounter in a race or fast group ride. Similarly, if you are a crit racer, time-trialist, or track cyclist, it is important that you understand that your max HR will be lower than an endurance cyclist. This is due in majority to the difference of metabolic energy production employed during competition in your event. Short range, high intensity cyclists rely heavily upon anaerobic metabolism for energy production, in part because of its ability to fill the energy void more quickly than aerobic metabolism.
However, because of the reduced need for oxygen, the VO2 max of a cyclist in this category is not incredibly high. Furthermore, the percentage of VO2max in which LT is breeched is very low (x<40%). In other words, you show me a cyclist with a very high VO2max, but who achieves LT at a very low percentage of VO2max, and I will show you a cyclist with a remarkable genetic potential.
Zone calculation is incredibly important especially as your fitness levels begin to reflect your training modes. As you become more aerobic you begin to delay the onset of anaerobic respiration, which in turn, demands more of your heart to continue delivering a steadily increasing supply of oxygen.
This, of course, will correlate with an increase in your VO2max. Without properly accounting for this upturn in fitness via zone calculation and adjustment, you will not be delivering the progressive overload your body needs to continue adapting- which means that you can write your own ticket to plateau county.
The point that I am trying to make is that for you to be consumed with max HR is just as futile as consuming yourself with VO2max.
These two near-functionless metrics are the metaphorical white bread surrounding the real flavor of the sandwich. While their value has meaning and is certainly a key indicator of overall fitness, training with these two parameters alone would be like walking into the Louvre, taking a few snapshots of the Mona Lisa, and then heading for the exit. Your overall aerobic physiological profile as related to race/event performance is a complex minutia of detail; when examined can provide a level of clarity that makes endurance training a questionless science NOT an art.
Your performance is determined NOT by the overall value of VO2max or max HR, but by the percentage of both metrics you are able to maintain for the longest period of time. Understanding and training on this principle will maximize your aerobic capacity, prevent physiological plateau, and optimize your fuel ratios.
If you have any questions please call me at 501-358-2112 or email me