VO2 vs RPE for Runners

Are you curious about the best way to track your training as a runner? Beyond just speed and distance, there are two major ways you can evaluate your running ability and focus your training.

First is VO2 max, or maximal oxygen consumption, is a measure of a person's aerobic fitness. Second is RPE or Rate of Perceived Exertion, a subjective measure that allows runners to gauge the intensity of their workouts based on how they feel, typically on a scale from 1 to 10.

What is VO2 Max?

The V in VO2 max stands for volume, while O2 stands for oxygen. VO2 max refers to the maximum amount of oxygen an individual can utilize during intense exercise, making it a key indicator of cardiovascular fitness and endurance capacity. Typically, VO2 max is measured as ml/kg/minute (milliliters of oxygen consumed per kilogram of body weight per minute of exercise).

Training to improve VO2 max typically involves high-intensity workouts, often at a perceived exertion level of 9 or 10 on the RPE scale, where efforts are short and all-out, such as during sprints or VO2 max intervals.

The most accurate measurement of VO2 max takes place in an exercise medicine lab. You’ll run on a treadmill while wearing a heart rate monitor and a mask to record how much oxygen you're taking in and how much carbon dioxide you're exhaling.

You can also measure your VO2 max yourselfwit hone of these techniques:

  • Use your fitness tracker: Some fitness devices like a Garmin or Forerunner provide VO2 max readings.

  • Use an online calculator: There are a number of online tools to measure VO2 max. Try one like this!

What is RPE?

RPE, or Rate of Perceived Exertion, is a subjective measure that allows runners to gauge the intensity of their workouts based on how they feel, typically on a scale from 1 to 10.

The RPE scale includes the following:

  • How fast you’re breathing.

  • How fast your heart is beating.

  • How tired your muscles are.

  • How much you’re sweating.

The scale is as follows:

RatingPerceived Exertion Level

  • 0 No exertion (at rest)

  • 1 Very light

  • 2 to 3 Light

  • 4 to 5 Moderate (somewhat hard)

  • 6 to 7 High (vigorous)

  • 8 to 9 Very hard

  • 10 Maximum effort (highest possible)

This method encourages a deeper connection between the mind and body, enabling runners to adjust their training intensity in real-time according to their physical and emotional state, as well as environmental conditions. For instance, a runner might aim for an RPE of 3-4 during easy or conversational pace runs, which aligns with Zone 2 training aimed at building aerobic fitness.

Should Runners use VO2 or RPE?

While VO2 max training focuses on pushing the physiological limits to enhance performance, RPE provides a flexible and intuitive approach that can accommodate the variability in day-to-day performance due to factors like fatigue, stress, and recovery.

Heart rate monitoring, often used alongside VO2 training, can be influenced by various physiological variables, including hydration status and environmental conditions, which can introduce inaccuracies. RPE, therefore, serves as a practical alternative or complement to heart rate-based training, especially for trail and ultrarunners who face diverse and changing conditions during their runs.

It’s not as much a question of which should you use, but rather a testament that you should use both. VO2 training is crucial for improving a runner's physiological capacity, while RPE offers a versatile and immediate feedback mechanism that supports sustainable and adaptive training practices. Integrating both approaches can lead to a well-rounded training regimen that addresses both the physical and perceptual aspects of running performance.

If you’re looking for more training guidelines, contact Oregon Running Clinic for a personalized training plan.

Charlotte Spangler