Should you train to failure, or is it best to leave a couple of reps in the tank? We explore this hotly debated bodybuilding topic.
When it comes to building strength and muscle, intensity matters. That means hard workouts generally produce better results. That’s because your body is actually pretty lazy and would prefer not to waste energy on building muscle. Therefore, there needs to be a significant stimulus to make it trigger hypertrophy.
But how intense do your workouts need to be to be effective? Opinions vary. On the one hand, fans of very high-intensity strength training say you need to push your muscles to failure or beyond to maximize hypertrophy. They believe that reps left in reserve (RIR) are wasted opportunities for growth.
On the other hand, more conservative approaches suggest that training to failure is unnecessarily demanding, and you can get the same results from less intense workouts, stopping several reps shy of failure.
Who’s right? Actually, there is evidence to support both points of view. And, as with many training topics, you’ll need to determine the approach that is right for you.
In this article, we explore when, why, and how to train to failure so you can decide if this is something you need to do for your gains and goals. But first, let’s make sure we’re all on the same page by defining what training to failure actually is.
What is Training to Failure?
One of the reasons that training to failure is such a controversial topic is that there are various interpretations of what failure is. Even studies on training to failure have different definitions, which doesn’t help make this topic any less confusing. So, what does training to failure mean, and how do interpretations vary? Let’s take a look!
1. Form Failure
This is the definition of failure that most lifters are familiar with. Form failure means you cannot do any more reps without changing your technique, e.g., using your legs and back to lift the bar during biceps curls. This is probably the most accessible form of failure training for most people.
2. Concentric Failure
Concentric failure occurs when you can’t complete the lifting phase of an exercise. For example, you can’t fully extend your arms during bench presses or lock out your squat or deadlift. While some lifters push themselves to concentric failure, most do not, as it can be dangerous and leave you pinned under a heavy bar. Concentric failure training often requires a spotter.
3. Speed/Velocity Failure
This is the type of failure often used in studies. It is best defined as the point at which your movement speed decreases by a certain percentage, usually around 20%. However, because most gym rats don’t have access to a velocimeter, this definition is of less practical use. Importantly, just because your movement speed decreases doesn’t mean you can’t crank out a few more reps. We even have a name for these slower repetitions – grinders. Most people can grind out several slow-mo reps at the end of a set. Speed/velocity failure is not very useful for our purposes.
4. Eccentric Failure
Eccentric failure occurs when you can no longer control the lowering phase of the exercise. For example, after reaching concentric failure during a set of pull-ups, you use your legs to help you get your chin above the bar and then lower yourself down. When you can no longer control your descent, you have hit eccentric failure. Eccentric failure happens after concentric failure because you are stronger eccentrically than you are concentrically. In other words, you can lower more weight than you can lift.
5. Isometric Failure
Isometric failure is the point where you can no longer hold a weight in a fixed position, e.g., the mid-point of a pull-up. This is the deepest level of failure you can reach, as it comes after concentric and eccentric failure. If you are so fatigued that you can no longer lift, lower, or hold a weight at the end of your set, it’s safe to say your muscles really are exhausted.
6. Metabolic Failure
Metabolic failure occurs when exercise by-products such as lactate accumulate to such a degree that you are forced to stop. For example, during a set of high-rep leg extensions, your quads might burn so much that the pain forces you to stop. However, this level of failure is not determined by muscle strength. Instead, it’s your ability to tolerate pain and clear lactate from your muscles, both of which vary according to training, experience, motivation, and genetics.
So, simply “training to failure” is not as straightforward as many people think, and there are degrees of failure from mild to extreme. For clarity and convenience, in this article, failure means form and concentric failure. They are the most widely used definitions and the most straightforward to implement. Things like speed/velocity failure and isometric failure are not really practical for our purposes.
Now we’ve defined failure, let’s move on to why training to failure can be beneficial.
Benefits of Training to Failure
Training to failure invariably means pushing past the point at which you’d normally want to end your set. In short, it’s gonna hurt! So, you probably want to know whether the reward is worth the effort.
To that end, let’s take a look at the main benefits of training to failure:
1. Increased Muscle Activation
Muscles are made of muscle fibers, and those fibers are grouped into motor units. Each motor unit is innervated or controlled by a single motor nerve. Motor units are recruited sequentially from smallest to biggest. The closer you get to failure, the more motor units you activate. Therefore, if you want to stimulate the maximum number of available muscle fibers, training to failure will help.
2. Enhanced Muscle Hypertrophy
Leading on from the point above, evidence suggests that training to failure may result in more significant muscle hypertrophy compared to non-failure training (1). This makes sense, given what we know about the importance of intensity in stimulating muscle growth.
3. Increased Metabolic Stress
Training to failure increases metabolic stress on the muscles. This stress leads to the production of metabolic by-products like lactate, which can further stimulate muscle growth. Metabolic stress is one of the three primary mechanisms of muscle hypertrophy, along with mechanical tension and muscle damage.
4. Enhanced Mind-Muscle Connection
Training to failure requires maximum effort and focus. This can help improve your mind-muscle connection, which is crucial for targeting specific muscles during exercises. By pushing yourself to failure, you become more aware of how your muscles are working and can better engage them during your workouts.
5. Psychological Benefits
Pushing yourself to failure and overcoming physical challenges can have significant psychological benefits. It can build mental resilience, discipline, and determination, which can carry over into other areas of your life.
Training to failure is a personal choice that depends on your goals, preferences, and overall training philosophy. It can be an effective way to stimulate muscle growth and improve strength, but it also carries risks of overtraining and injury. It’s important to listen to your body, track your progress, and adjust your training accordingly.
Ultimately, the decision to train to failure or not should be based on your individual needs and preferences. Experiment with different approaches, consult with a qualified trainer or coach, and make informed decisions that align with your goals.
Remember, there is no one-size-fits-all approach to training, and what works for one person may not work for another. Stay consistent, stay safe, and keep pushing yourself towards your fitness goals.