Myth vs. Fact: Do You Really Have to Train to Failure to Build Muscle?
- Benjamin Duperron
- Jun 21
- 4 min read
I often hear athletes and gym-goers echoing a common mantra: "Go big or go home!" or "You're not working hard enough unless you're hitting failure on every set!" While the sentiment of pushing yourself is admirable, the idea that you must train to muscular failure every single session to build muscle is a myth that can actually hinder your progress and increase your risk of injury.
Let's clear this up.
The Myth: You Have to Train to Failure to Build Muscle
Many believe that the only way to stimulate muscle growth (hypertrophy) is to push each set until you literally cannot complete another repetition with good form – also known as "training to failure." The logic seems sound: if you push your muscles to their absolute limit, they'll be forced to adapt and grow stronger.
The Fact: The Importance of "Reps in Reserve" (RIR) and How Training to Failure Every Session Can Hinder Recovery and Progress.
While training to failure can be an effective tool in specific circumstances, it's far from a universal requirement for muscle growth. In fact, consistently pushing to failure on every set can be counterproductive. This is where the concept of Reps in Reserve (RIR) comes into play.
What is Reps in Reserve (RIR)?
RIR is a simple, yet powerful, way to gauge the intensity of your sets. It refers to the number of additional repetitions you could have completed with good form before reaching muscular failure.
RIR 0: You trained to failure (no more reps possible).
RIR 1: You could have done 1 more rep.
RIR 2: You could have done 2 more reps.
RIR 3: You could have done 3 more reps.
Why Not Train to Failure All the Time?
Here's why relying solely on training to failure can be detrimental:
Increased Fatigue and Impaired Recovery: Pushing to failure is incredibly taxing on your central nervous system (CNS) and muscular system. Doing this frequently can lead to excessive fatigue, extended recovery times, and even overtraining. If you're constantly fatigued, your subsequent workouts will suffer, and your overall progress will slow down.
Higher Risk of Injury: When you push to the absolute limit, your form often degrades. This significantly increases your risk of injury, especially with complex compound movements like squats, deadlifts, and bench presses. Sacrificing form for one more rep is never worth it.
Diminishing Returns for Hypertrophy: Research consistently shows that most of the muscle growth stimulus occurs within a few reps before failure. Training with 1-3 RIR provides almost the same hypertrophic benefits as training to failure, but with far less fatigue and risk.
Reduced Training Volume: Because training to failure demands longer recovery, you might find yourself needing to do fewer sets or workouts per week. By leaving a few reps in the tank (1-3 RIR), you can often perform more total quality sets over the week, leading to greater overall volume and potentially more growth in the long run.
Impact on Technique and Skill Acquisition: When you're constantly grinding out reps to failure, it's harder to focus on refining your technique. Leaving RIR allows you to practice movements with crisp, controlled form, which is crucial for long-term strength development and injury prevention.Effective Alternative Strategies
When Can Training to Failure Be Useful?
While not for every set or every session, training to failure still has its place in a well-structured program:
Periodically: As a training "intensifier" for certain blocks of training (e.g., once every few weeks or as a final set on an isolation exercise).
Isolation Exercises: It's generally safer and less fatiguing to take isolation exercises like (bicep curls, tricep extensions, or lateral raises) to failure compared to heavy compound lifts.
To Gauge Max Effort: Occasionally testing a set to failure can help you better understand your current strength levels and how to accurately assess RIR in subsequent sets.
The Takeaway for Your Training:
For most of your working sets, especially with compound exercises, aim to finish with 1-3 Reps in Reserve (RIR). This "sweet spot" allows you to:
Maximize muscle growth stimulus.
Manage fatigue effectively.
Maintain excellent form.
Reduce injury risk.
Ensure consistent, long-term progress.
Don't let the "no pain, no gain" mentality fool you into counterproductive training. Smart training, consistent effort, and understanding RIR will get you further on your strength and muscle-building journey than blindly pushing to failure every time.
References:
References & Further Reading:
Grgic, J., Schoenfeld, B. J., Orazem, J., & Sabol, F. (2021). Effects of Resistance Training to Muscular Failure Versus Non-Failure on Strength and Hypertrophy: A Systematic Review and Meta-Analysis. Journal of Strength and Conditioning Research, 35(5), 1431-1440. (This meta-analysis offers strong support for the effectiveness of RIR training.)
Schoenfeld, B. J., et al. (2019). Resistance Training Volume Enhances Muscle Hypertrophy. Medicine & Science in Sports & Exercise, 51(3), 488-494. (Highlights the importance of total training volume, which RIR training can help optimize.)
For more in-depth explanations on RIR and training to failure, check out resources from the National Academy of Sports Medicine (NASM) Blog or the in-depth articles by Stronger by Science.
https://www.empower.physio/blog-all/rpe-vs-rir-part-ii-how-do-i-use-them
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