Calculating Heart Rate Zones for Cyclists: The Complete Guide

Why train with heart rate?

Heart rate training is one of the most accessible ways to systematically get stronger on the bike. Your heart is an honest measure of your effort: it accounts for fatigue, heat, stress, and sleep. By training in the right heart rate zone, you prevent your easy rides from becoming too hard and your intervals from becoming too easy. The result is more progress with less risk of overtraining.

Determining Heart Rate Zones: Two Methods

There are two common ways to calculate your zones. The simplest is based on your maximum heart rate (HRmax). The rule of thumb 220 minus age gives a rough estimate, but can be significantly off. A better method is a maximal test on the bike, for example, a standing start followed by an all-out sprint after a solid warm-up.

The second method uses your lactate threshold heart rate (LTHR or FTHR). You determine this with a 20 or 30-minute time trial at a consistent intensity. The average heart rate over the last 20 minutes is your FTHR. This method is more precise and is recommended by many coaches.

The Five Classic Zones

Based on your FTHR, you divide your training into five zones. Each zone has its own purpose:

• Zone 1 (recovery): less than 81% FTHR, for active recovery and easy rides.
• Zone 2 (endurance): 81 to 89% FTHR, ideal for long rides and fat burning.
• Zone 3 (tempo): 90 to 93% FTHR, for sustained tempo blocks.
• Zone 4 (threshold): 94 to 99% FTHR, your race and climbing pace.
• Zone 5 (VO2max): 100% and higher, for short, explosive intervals.

Reliable Measurement with the Right Sensor

Accurate zones are of little use if your measurement is incorrect. A chest strap remains the gold standard and responds much faster than a wrist-based sensor, especially during intervals. Combine it with a bike computer or your smartphone via ANT+ or Bluetooth. Check out our complete selection of heart rate monitors, from Polar H10 to Garmin HRM Pro and Wahoo TICKR.

Want even more insight? Connect your heart rate monitor to a power meter and possibly a cadence or speed sensor. The combination of watts, revolutions per minute, and heart rate shows exactly how efficiently you are training and when fatigue sets in.

How to Apply Your Zones in Practice

Start with a long easy ride in zone 2, followed by a short interval training in zone 4 later in the week. Repeat your FTHR test every six to eight weeks, as your zones shift with your fitness. Log your training sessions in an app like Strava, TrainingPeaks, or Zwift and see if you are truly in the intended zone.

With the right sensor and properly set zones, every ride transforms into a targeted training session. Whether you're training for your first tour ride or competing in a classic race, heart rate zones provide direction and structure.