How to Tell How Hard You’re Exercising

Exercise intensity can be monitored even when no watch, chest strap, or other heart-rate device is available. The body provides several cues that change as effort increases, and learning to notice those cues can make intensity easier to judge during a workout. Some of the most useful methods turn those everyday sensations into simple ways of describing how demanding the exercise has become.

Two commonly used approaches are rating of perceived exertion, or RPE, and the Talk Test. RPE focuses on the overall sense of effort, while the Talk Test uses the ability to speak comfortably as exercise intensity changes .^1,4

RPE asks you to rate how hard the exercise feels overall. The original Borg RPE scale runs from 6 to 20, with 6 representing no exertion or essentially resting effort and 20 representing maximal exertion. RPE can be used to guide exercise intensity without requiring continuous heart-rate feedback. How RPE is interpreted can vary with factors such as exercise mode, familiarity with the scale, and the instructions being used. It is therefore better treated as its own measure of perceived effort rather than as a way to reproduce a particular heart-rate value .^1,2

The Talk Test approaches intensity from a different direction by asking whether comfortable speech can be maintained during exercise. As comfortable conversation becomes difficult, exercise intensity is generally approaching or exceeding a ventilatory or lactate threshold. The Talk Test provides a practical estimate rather than a direct measurement of those physiological thresholds. Formal Talk Test protocols usually use standardized speech and responses such as positive, equivocal, or negative, so informal rules based on an exact number of words should not be treated as universal cutoffs .^3,4

The advantage of these methods is that they make exercise intensity easier to notice in real time without depending on a device. With practice, changes in effort and speech can become familiar signals that help distinguish an easier session from one that is becoming substantially more demanding. They do not turn subjective experience into a laboratory measurement, but they can make the sensations that accompany exercise more useful and easier to interpret.