What Heart Rate Zone Should You Train In?

Heart rate zones are commonly used to structure endurance training and control training intensity. Training in the correct zones helps athletes build aerobic fitness, improve endurance and avoid doing too much training at high intensity.

Most endurance training should be done at relatively low intensity. This is often referred to as Zone 2 training or aerobic training. Training at this intensity improves aerobic capacity, increases mitochondrial density and improves the body’s ability to use fat as a fuel source.

Higher intensity training sessions are still important, but they should be used strategically rather than performed every day. Easy runs, long rides and recovery sessions should usually be done at low intensity.

Heart rate zones can be calculated using maximum heart rate or threshold heart rate. Threshold heart rate is usually more accurate for endurance training because it reflects sustainable effort rather than theoretical maximum effort.

You can calculate your zones using the Heart Rate Zones Calculator on this site.

The key point is that endurance training should not feel hard every day. Consistency and appropriate intensity are more important than constantly pushing hard sessions.