The Importance of Exercise Intensity
Exercise intensity is one of the most crucial factors in determining the effectiveness of a workout. This intensity is measured through different parameters such as power, heart rate, pace and RPE (Rating of Perceived Exertion). RPE is a simple, subjective way to measure exercise intensity based on how you feel during exertion. While it may seem antiquated compared to modern devices, it is surprisingly accurate and useful.
RPE scales
There are two common RPE scales: the Borg scale of 6-20 and a simpler scale of 0 to 10. In both scales, greater effort translates into a higher RPE value. The Borg scale, used in physiology laboratories, ranges from 6 (no effort) to 20 (maximum effort). Multiplying the number of perceived exertion by 10 gives an approximation of the heart rate. Although accurate, this scale is not intuitive outside the laboratory. For this reason, many cyclists prefer the 0 to 10 scale, where 0 is no effort and 10 is maximum effort.
RPE and the Conversation Test
The Talk Test is a simple way to use the RPE. As the intensity of the exercise increases, speaking becomes more difficult. An easy pace allows for full conversations, while maximum effort allows only single words to be spoken between gasps. This test also helps to assess the effort of a training partner by listening to their breathing or trying to engage them in conversation.
10-Point RPE Scale
| RPE | Effort | Speaking Ability |
|---|---|---|
| 0-1 | Little or no effort | Speak freely, breathe through your nose |
| 2-4 | Active recovery rate | Speak comfortably |
| 4-5 | Aerobic “cruising” pace | Speak comfortably, breathe through your mouth. |
| 6 | Aerobic pace of “tempo”. | Speaks in short sentences, breathes with difficulty |
| 7-8 | Lactate threshold rate | Speaks in short sentences, labored breathing |
| 8-9 | Time trial or hard climbing | Loose words between gasps |
| 10 | Maximum effort | Grunting, moaning, crying |
Using RPE in Training and Competition
RPE is useful for any type of exercise and is especially valuable during competition. It provides context to power and heart rate data, helping cyclists assess intensity without relying solely on technology. During races, RPE is an accurate and realistic way to measure intensity, especially in varying conditions such as altitude or weather.
RPE and Recovery Monitors
Perceived exertion ratings can also supplement data from recovery monitors such as Garmin, Wahoo or Coros. If these devices indicate that you are recovered, check with your RPE to see how you really respond to intense efforts.
Measuring Training Progress with the RPE
RPE can indicate progress even without changes in power output or pace. For example, at the beginning of the season, a 20-minute climb at 250 watts may feel like an effort of 7. Later, when your fitness has improved, that same climb at 250 watts may feel like an effort of 6. An RPE of 7 to 8 on the climb may translate to 275 watts at the height of the season.
Competing by Sensations: RPE in Competition
In racing, RPE is often the best way to measure intensity. Factors such as altitude, temperature and fatigue affect heart rate response and power output. Learning to race by feel, rather than relying on numbers, can lead to the best performances. Keep recording data for later analysis, but in the moment, it is crucial to be able to assess intensity without looking at a screen.
Objective: to understand the sensations
One of the biggest goals when working with cyclists is to teach them to train and compete by feel. The best performances often occur when cyclists tune their bodies rather than focusing on the numbers. The goal of a skilled cyclist, even if recreational, is to learn to use technology effectively while reducing their dependence on it.
