Types of Failure

Before we attempt to manipulate intensity as a variable in training, we first should define what failure actually is.

I like to break it down into three stages:

1) Technical Failure

When you hit a technical failure, you did not fail to complete a full rep, but you will not be able to do another with proper form.
This will obviously be a best guess since you cannot know if you are going to fail the next rep unless you try it, but as you gain experience, you will quickly learn to gauge the difference between technical failure and other types of failure.

Most of our exercise prescriptions refer to this definition of failure.

2) Concentric Failure

Concentric failure is the point in which the target muscle(s) can no longer move the external load, irregardless of technique or safety precautions.
This is what most people think of when they hear “failure”, but it’s often not the best target to shoot for when taking risk, fatigue, and sustained performance into account.

3) Eccentric Failure

Whereas concentric failure is the inability in the muscle fibers to shorten, eccentric failure is the inability to resist lengthening under load.
Eccentric failure is rarely going to be a goal in normal training, but it’s important to define in order to complete the failure picture.