If you’ve been in the gym long enough, you’ve probably heard that pushing your sets to complete failure is the key to muscle growth. But is it really necessary? Let’s break down the science behind training to failure and whether it’s a must for maximizing your gains.

What is Muscular Failure?

Muscular failure happens when your muscles can no longer produce enough force to move a given weight. This occurs as a response to accumulating fatigue and an inability to recruit more motor units to sustain the effort. Essentially, you reach a point where you physically cannot perform another rep with good form.

The Science Behind Failure Training

The principle of motor unit recruitment helps explain why some believe failure training is necessary. Motor units (a nerve and the muscle fibers it controls) are activated in a specific order. Lower-threshold motor units, which are associated with type I (endurance-oriented) muscle fibers, fire first. As these fatigue, the body recruits higher-threshold motor units that activate type II (strength and power-focused) muscle fibers.

The theory behind training to failure suggests that only by reaching this complete exhaustion do you ensure full recruitment of all possible motor units, which could potentially maximize muscle size and strength.

What Does the Research Say?

While some studies have suggested that training to failure can be beneficial, others indicate that it may not be necessary—or could even be detrimental in some cases. A 2022 systematic review and meta-analysis by Grgic et al. examined 15 randomized controlled trials comparing training to failure versus stopping short of failure. Here’s what they found:

• Total Participants: 394 (265 males, 129 females), all young adults
• Duration: 6 to 14 weeks
• Training Frequency: 2-3 days per week
• Subjects: Both trained and untrained individuals
• Quality of Studies: Moderate to good methodological quality

The results? Training to failure wasn’t definitively superior for muscle growth or strength gains. This suggests that while failure training might be one strategy, it’s not the only way—or even the best way—to achieve results.

Should You Train to Failure?

The answer depends on your goals, experience level, and overall training volume. Here are some key takeaways:

• For Beginners: Training to failure too often can lead to excessive fatigue and hinder recovery. Stopping 1-2 reps shy of failure (known as leaving “reps in reserve”) is often more sustainable.
• For Advanced Lifters: Occasionally training to failure can be useful, particularly for smaller muscle groups or as a tool to break through plateaus. However, going to failure on every set may lead to increased fatigue and a higher risk of overtraining.
• For Strength Gains: Research suggests that training close to failure (but not necessarily to complete failure) is just as effective for building strength while reducing injury risk.
• For Hypertrophy: Maximizing muscle growth doesn’t require failure training in every set. Consistency, progressive overload, and proper recovery are far more important factors.

The Bottom Line

You don’t have to train to failure to build muscle and strength effectively. While it can be a useful tool in certain contexts, it’s not the end-all-be-all of resistance training. Instead, focusing on progressive overload, good technique, and smart programming will yield better long-term results without unnecessary fatigue or risk of injury.

Looking to optimize your training plan? Our Fitbliss coaches can help tailor a program that balances intensity and recovery for your specific goals!