Types of Failure

Before we go any further, we first should define what failure actually is. I like to break it down into 3 stages: 1) technical failure, 2) concentric failure, and 3) eccentric failure. 

Technical failure is the first to present itself and is when form breaks down to the extent that safety and/or intent become compromised. This type of failure point will be most important when performing heavy, compound exercises like squats and deadlifts due to structural (and technical) limitations that commonly present before muscular failure. Picture the knee valgus during squats or the back rounding during deads—at this point, the set cannot be continued with integrity but additional reps can be completed. 

Next comes concentric failure, or the point in which the target muscle(s) can no longer shorten against the external load. This is what we inherently think of when we hear “failure”. Images of bench presses stuck halfway up immediately come to mind. 

Last, but certainly not least, is eccentric failure. Whereas concentric failure is the inability in the muscle fibers to shorten, eccentric failure is the inability to resist lengthening under load. This is possible because of a cool feature of our microscopic sarcomeres: more tension can be controlled through lengthening versus volitionally acted upon through shortening. Eccentric failure is rarely a target in normal training, but it’s important to qualify this late stage of muscular failure to complete the picture. 

Between technical and concentric failure, I tend to refer almost exclusively to the former when discussing this topic. And the rest of this course will imply technical failure unless otherwise specified.