This is likely the most overrated metric in all of endurance sports. Remember, intensity is the key, not volume. Certainly there is a bell curve of the amount of volume which will help stimulate maximal adaptation, and that bell curve is dependent on many things for different athletes, the most important being the individual athlete’s previous training history, and individual training response. How you can figure out the right amount of volume for you or your athlete is the entire purpose of technology and training. Technology allows us to dial in training stress specific to our bodies and goals, in terms of volume and intensity.
Heart Rate (HR)
If volume is the most overrated metric in all of endurance sports, heart rate is the second most overrated metric. No one ever won a race based on the heart rate they achieved. HR is measured by beats per minute, or bpm. How high your HR can reach doesn’t mean a thing, but you’ll hear athletes brag about the bpm they reached in a workout or race. In truth, if you take an out of shape, overweight individual, and have them go for a jog, their HR will likely be higher than that of a fit individual. HR plays a role in determining a few important metrics we will discuss, (see my Efficiency Factor post), but HR by itself doesn’t really mean much.
I realize for a lot of you, this sounds earth-shattering. Why wouldn’t you pay attention to HR in the workout or in the race? How am I supposed to judge how I’m doing? What if my HR gets high? What if it doesn’t get high enough? The answer is, it doesn’t matter. HR is variable from athlete to athlete, and even day to day within the same athlete, sometimes due to training, sometimes due to things which have nothing to do with training.
The main issue with athletes getting so hung up about HR is that it is a metric which truly doesn’t mean anything by itself. My wife can reach heart rates over 200 bpm in a run workout, while I can go as hard as possibly and never break 185 bpm. Does this mean she is faster than me? No, of course not.
You probably noticed that when you start an interval, heart rate lags behind, as it takes awhile to catch up. If you’re doing very short intervals, say 15 seconds or less, there isn’t enough time for HR to catch-up to truly represent the intensity of the effort. It’s just an input metric, communicating how your body is responding to the stress you’re giving it in the moment. You can’t do much with that.
Output metrics on the other hand, such as the pace you run at, mean something. If I told you I did a run at 150 bpm, you wouldn’t really know what that means. Was it a fast run? A slow run? But if I told you I did a run at 6 min mile pace, now you understand how fast that is. Output is the entire point of performance and competition.
I want to be clear about HR though, as you should collect HR during just about all training sessions. Sometimes you should actually pay attention to it during the session, but those sessions will be outlined later on by me here. Otherwise HR should be given no attention during a session. It is important to collect it for later analysis, but otherwise don’t let it dictate the workout, and NEVER let it dictate your racing.