If you are a competitive cyclist, you have heard of zone training and used some form of it during your training. However, if you are the average weekend warrior, or just starting your first training program, zone training might be something new that is worth implementing into your workouts.​

Zone training is described as categorizing the intensity of exercises into “zones” based on certain physiologic parameters. These parameters can vary from your heart rate, blood lactate levels, VO2 max, or even which type of muscle fibers are being recruited during the exercise. The zones match up to the perceived exertion level of the exercise. The rate of perceived exertion within each zone of exercise correlates to the values of each of these following parameters (% Max HR, Lactate, Muscle fiber type) :


Rate of Perceived Exertion (RPE) (1-10)


Lactate (mmol/L):

Muscle Fiber Type:

1, 4, <68%,<2, Type I

2, 5-6, 69-83%, 2-3,Type I

3, 7, 84-94%, 3.5-5, Type I-IIa

4, 8-9, 95-100%, 5-8, Type IIa

5, 10, NA, >8, Type IIa-b

6, 10+, NA, Type IIb​

While measuring blood lactate can be a helpful biomarker to determine which aerobic zone you are in, it can be more invasive and expensive to track. Therefore, most people determine their training zones from their heart rate and rate of perceived exertion levels.

Another good rule of thumb is the conversation test: If you are exercising and can hold a conversation while speaking full sentences, this correlates to zone 2. If you can only talk in small phrases, you have entered zone 3. The effort from zones 4 and up would make it extremely difficult to verbally communicate altogether.​

Studies have shown that training in zone 2 is ideal for improving mitochondrial density and function, which can improve insulin sensitivity and increase the efficiency of fat oxidation. Zone 5 training is considered VO2 max training, which can improve overall power output and aerobic capacity. The amount of time spent in each zone depends on your overall goals of training, however, a good program should dedicate at least some time in each zone to maximize the impact of your workouts.