Have you ever finished your workout and felt like you still had energy? Do you feel like you haven’t seen the amount of physical progress you’d expect given the amount of time you’ve spent in the gym?
If so, you may be missing a crucial component of training for muscle growth.
It’s known by a few different names: The failure point, point of exhaustion, muscle shock, or volitional fatigue. While failure isn’t something you’d typically strive for in other areas of life, failure at the gym can be a great thing. By learning to push your muscles to the point of failure, you can give them the signals they need to grow, which, in turn, may help you accomplish the results you’re looking for.
Ready to see some gains? Get ready to leave the gym feeling exhausted and proud of it!
It is very important to stress that your goal during weightlifting sessions should always be to maintain perfect form, first and foremost. Once you’ve reached the rep at which you can no longer lift without sacrificing form, then, and only then, you have reached the point of failure.
This is actually so crucial I’m going to emphasize it twice: do not sacrifice form to get an extra rep. If you break form while lifting weights, you may accidentally injure yourself, which could potentially force you to sit out the next few weeks, completely negating any improvements you intended to achieve.
Let’s say you are doing a standard dumbbell curl and you have reached the failure point before your final set. What you might want to do is drop to a lighter weight until you finish your set without sacrificing form.
Do this at your discretion. If you are failing during the last few reps of your last set then you have done your job and stimulated your muscles; put the weights down and move on to the next exercise. Don’t force an injury on yourself by trying to push past failure. The secret is to work up until you hit failure, not beyond that point.
Arnold Schwarzenegger, while in his prime, would use a method of dropping weight during his training routine in order to maximize the failure point and do what he believed was “shocking” his muscles into growth. During sets of bench presses, Arnold would perform these drop sets until failure.
In an interview, Schwarzenegger explains that he’d do “...20 reps of 315 [pounds], and then have guys pull off plates. Then I'd do 10 reps of 225, and then I'd have the guys take off another pair of plates. I'd have 135 left and I'd see if I could do 15 or 20 reps… All of a sudden your pectoral muscle is shaking. You don't know what to do because it's cramping and being tortured. It's in pain because you've now shocked the muscle." 
This method of driving your muscles to that moment they’re shaking is exactly what the point of failure should feel like. Fitness professionals agree that working to exhaustion changes muscle fibers in a way that leads to significant growth.
But what kind of scientific support does this concept have?
At the University of Florida, a clinical trial was conducted on this principle. Participants were split into two groups to perform the same exercise over the course of several weeks. One group would train to volitional fatigue (failure point) of 7-10 reps on a Nautilus knee extension machine, and the control group would not. 
This was in an effort to monitor and record any change in muscle development stimulated by the difference in approach to the exercise. The group that was the control group did not have any change in strength, while the group who trained to fatigue saw an increase in strength.
“The training group improved their 1-RM and 7-10 RM strength (by 31.7 and 51.4%, respectively) (P < or = 0.01) while the control group did not change,” researchers noted. 
For an extremely intense workout, try this approach:
Once a week, on the day before your rest day, pick an exercise that you perform fairly well, or one that you like to perform. On your last set of that exercise, drop down 10 or 15 pounds and try to do an uncounted set of infinite reps. Keep doing the reps until you simply cannot move the weight anymore without your form being sacrificed, then drop the weight down another 5 pounds and repeat until the point of failure.
Keep repeating this dropping set until even performing the movement without weights becomes a challenge. The next few days might be painful, but it’s a surefire way to mix-up your routine and introduce the failure point into your regimen.
1. Arnold Schwarzenegger’s 3 favorite lifting methods, http://www.bodybuilding.com/fun/arnold-schwarzeneggers-3-favorite-lifting-methods.html, March 2015
2. Effect of training on the relationship between maximal and submaximal strength, http://europepmc.org/abstract/med/8423746, March 2010