Reps in Reserve (RIR) is a training concept that refers to how many more repetitions you could perform at the end of a set before reaching failure. For example, if you finish a set with 2 RIR, it means you could have done two more reps but stopped to avoid complete muscle fatigue. This approach helps manage training intensity and recovery by preventing excessive muscle exhaustion.
Flexibility training, on the other hand, focuses on improving the range of motion and mobility of muscles and joints through stretching exercises such as dynamic stretches before workouts and static stretches afterward. Consistent flexibility work can reduce injury risk and enhance movement efficiency.
The interaction between Reps in Reserve and flexibility training lies mainly in how managing fatigue through RIR can support better movement quality and safer flexibility work. When you stop strength exercises with some reps left in reserve, your muscles are less fatigued, which allows you to perform flexibility exercises with better control and less risk of overstretching or injury. Conversely, improved flexibility can enhance your ability to perform strength exercises with proper form, potentially allowing you to push closer to failure safely when appropriate.
Using RIR to avoid training to failure means you maintain better muscle function and joint stability, which is beneficial when performing flexibility drills that require controlled movement and muscle engagement. For example, if you train with 1-3 RIR, you preserve enough muscle capacity to execute dynamic stretches effectively before workouts and static stretches after, supporting overall performance and recovery.
In summary, managing your effort with Reps in Reserve helps maintain muscle readiness and joint health, which complements flexibility training by enabling safer and more effective stretching routines. Flexibility, in turn, supports strength training by improving range of motion and movement quality, creating a positive cycle between the two.
Sources
https://www.fitbudd.com/academy/strength-and-conditioning-meaning-principles-and-benefits
https://www.runnersworld.com/training/a69204484/stretching-myths-for-runners/
https://betterme.world/articles/calisthenics-daily-workout-plan/
