The Biggest Mistake Athletes Make with Training Zones

by Bethany Rutledge

If you look at any forum where new triathletes gather whether it be reddit, beginner triathlete, or even Slowtwitch, there still exists much confusion over the use of heart rate and the proper use of zones. I am consistently surprised by the number of people who use the default zones from their training device as gospel. These zones are calculated off of max heart rate and are virtually meaningless unless you get lucky and happen to have both the same max and derivative zones in their formula.

With the increasing availability of optical heart rate sensors (wrist heart rate) on GPS watches, fit bits, and apple watches, more athletes than ever have heart rate at their fingertips.  Which is a good thing! However, it also means more confusion, since many athletes with little interest in the science of training are using heart rate. Thus, it is not unusual to hear athletes claiming to do all their runs in zone 5, perform three-hour rides at an IF of 1.2 or other impossible feats.

Let me ask you a few questions: Do you have too much money in the bank?  Am I too old for this? Are these pants too tight? What do those questions all have in common? The answer is that they’re all subjective, just like the question of whether your heart rate is too high, low, or just right.

In order for heart rate to provide value, you require a north star and that star is your lactic threshold heart rate. There are a few good ways to find this value, which by the way, will likely be different on the bike versus the run. If you don’t have a coach to help you, then consider getting a lab test to help you get started. If you’re on your own, check out Joe Friel field tests to get a good sense of where you’re at. Or, if you’re local to Atlanta hit up an Energy Lab FTP test to get a good estimate of your cycling lactic threshold heart rate.

There is much to be said about zone training after you’ve properly set your zones. But the first step is getting both your run and cycling zones, nailed down accurately. Happy training!