Learn All About Muscle Failure

Muscle failure refers to lifting weights to the point where a muscle can no longer contract concentrically. That's a fancy way of saying that your muscle is experiencing a momentary failure, the inability to perform another repetition.

Training to Failure
Most of us regular exercisers don't train to complete failure. Those who do are usually bodybuilders, powerlifters, people involved in competitive strength training or people working to build larger muscles.
What does that mean for the rest of us? Is the only way to build lean muscle tissue to train to muscle failure?

How We Build Muscle
The way our bodies build muscle is by lifting more weight than it can handle. In other words, we overload the muscle and, by doing that, our muscles adapt by growing more and bigger muscle fibers to handle that added weight. The ultimate form of overload is to train to momentary muscle failure, which is why many pros use this kind of training for muscle building, but there's no consensus that this is the best kind of training for building muscle.

What Is Muscle Failure?
So, what does muscle failure feel like? For those of us who don't lift to failure, it probably feels very uncomfortable. The idea is that you do as many reps as you can with good form until you're tired. Then? You keep going until you can barely get through the last rep. You don't want to drop the weight on your head, of course, but recognize when your form is going and stop at that point.

This type of training recruits the maximum number of motor units and muscle fibers you can, which is why it's the choice for people who want to build larger muscles.