The rate of perceived exertion (RPE) is a subjective scale that guides training intensity by allowing individuals to assess their effort level during exercise. RPE helps individuals understand how hard they are working, enabling them to tailor workouts based on their fitness goals. For instance, aiming for a specific RPE can enhance workout effectiveness, whether for endurance or strength gains. It's particularly beneficial for those who may not have access to heart rate monitors. RPE empowers exercisers to tune into their bodies and adjust intensity accordingly.