Science

Train to Fail

Most lifters aren’t lifting with enough intensity to maximize hypertrophy, which is slowing down their muscle gain.

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By Krystal Khine

Novice and advanced lifters make the same mistakes session after session. Exercise selection, technique, volume, and recovery are common mistakes, as they’re all necessary factors to account for when trying to build muscle. Most lifters nail those down to an adequate level sooner rather than later. In reality, the factor that distinguishes a lifter who builds muscle from one who doesn’t generally isn’t any of these—it’s training intensity, and most lifters lack enough of it. 

The primary drivers of hypertrophy, or muscle gain, are often misconstrued, which contributes to the ineffective training habits of most lifters. For decades before modern anesthesiology, anecdotal evidence suggested that muscle soreness—damage to the muscle fibers—was driving muscle gain because muscle fibers seemed to be built back stronger after. From a logical standpoint, that makes sense. After a hard workout, one is bound to be sore, and that soreness reminds us of hard work. But recently, it’s been revealed that damage to the muscle, or “fatigue,” doesn’t build muscle, and is actually counterproductive to hypertrophy. 

The actual mechanism that stimulates hypertrophy is mechanical tension, or the force that is exerted on a muscle fiber. For a muscle to experience any significant degree of mechanical tension, it must be contracted with resistance. To experience more mechanical tension, there must be more resistance or load. This is why resistance training (usually weightlifting) builds muscle mass, but other beneficial activities like running or walking that also subject our muscles to some mechanical tension don’t; those activities provide our muscles with far less resistance, and thus less mechanical tension. To maximize mechanical tension in resistance training, a lifter must train with uncomfortable levels of intensity. There should be a point in a set of resistance training at which the contraction involuntary slows down. Once a lifter is lifting with enough effort and intensity to push their limits, they will eventually reach a point at which the movement doesn’t just involuntarily slow down, but stops completely, no matter how hard they may attempt to complete a repetition. That’s muscular “failure,” and unlike what we associate it with in general English, it’s a good thing in the context of lifting.

Lifting with maximal amounts of mechanical tension will trigger a stimulus and improvement. But to build significant muscle, a lifter must increase the resistance across sessions so that when their strength and muscle mass increase over time, they’re still achieving equally high degrees of mechanical tension. That’s known as progressive overload, and it’s extremely crucial for hypertrophy. Over time, progressive overloading allows the body to put on muscle mass. 

Up until very recently, the science related to the benefits of training to failure lacked consensus—it claimed that training to the brink of failure, but not all the way to it, has similar net results as training to complete failure whilst inducing slightly less fatigue. However, most lifters who read that were still training to failure in the hopes of maximizing gains. Those who trained to failure were still seeing substantial results. Generally, people who are unable to gauge how close they are to failure terminate their sets far too early. Due to this, a good lifting strategy is to train to one’s absolute limit in order to reduce the risk of terminating a set too early. 

However, the disagreement over when to terminate a set was recently resolved through new studies. In early 2021, a meta-analysis in the Journal of Sport and Health Science showed that training to muscular failure rather than training to the brink of it has no significant detrimental differences. The consensus of the scientific and lifting communities is clear—train until you cannot physically complete another repetition of the exercise. 

While it may sometimes feel scary to lift with very high intensities because of injury risk, it’s actually perfectly safe. Resistance should be heavy enough that it is at an intense level, but not so heavy that every repetition requires excessive cheating (unintentionally using other muscles to relieve intensity) or form breakdown. Training to failure’s immense benefits for hypertrophy are clear and supported by extensive research. Along with accounting for the other crucial factors for hypertrophy, such as an adequate protein intake and amount of sleep, using the highest intensity that you can manage will maximize gains. Whether you train to gain muscle, prevent injury, or for fun, training to failure should be a vital part of everyone’s workout program.