Reps in Reserve (RIR) is a method used to estimate how many more repetitions you could perform at the end of a set before reaching muscle failure. It helps gauge training intensity without always pushing to complete failure. However, when you lack experience, accurately judging your RIR can be challenging because it requires a good sense of your own limits and fatigue levels, which beginners typically have not developed yet.
For beginners, the accuracy of RIR is often lower because they may not fully understand what true muscle failure feels like or how to pace themselves during sets. They might either stop too early, thinking they have no more reps left when they actually do, or push too hard and misjudge how many reps remain. This can lead to inconsistent training intensity and less effective workouts. Experienced lifters develop a better internal sense of effort and fatigue, making their RIR estimates more reliable over time.
Despite this, using RIR as a rough guide can still be beneficial for beginners. It encourages stopping sets before complete failure, which helps manage fatigue and reduces injury risk. Beginners are often advised to aim for leaving 1-3 reps in reserve, which balances effort and recovery. Over time, as they gain experience and better body awareness, their ability to estimate RIR improves, allowing for more precise control of training intensity.
Research and coaching advice suggest that training with moderate to high effort—often leaving 1-3 reps in reserve—is effective for muscle growth and strength gains. Beginners should focus on learning proper form and gradually increasing intensity rather than obsessing over perfect RIR accuracy. Using RIR alongside other cues like how the muscles feel and overall fatigue can help beginners progress safely and effectively.
In summary, while RIR is a useful tool for managing workout intensity, its accuracy is limited for those lacking experience. Beginners should use it as a flexible guideline rather than a strict rule, focusing on consistent effort and gradual improvement in self-awareness.
Sources
https://sweat.com/blogs/fitness/guide-to-sets-reps-and-rest
https://rippedbody.com/rpe/
https://dr-muscle.com/maximizing-muscle-growth-the-role-of-rpe-in-hypertrophy/
https://betterme.world/articles/building-a-workout-plan/
https://smart.dhgate.com/mastering-how-to-calculate-rpe-a-practical-guide-to-optimizing-your-workout-intensity/
