The secret to faster muscle gains

In order to stimulate muscle growth you need to create muscle fibre damage through resistance training. BUT the eccentric, lengthening phase of an exercise creates more muscle fibre damage (larger gains) than the concentric, shortening phase. That's where the concept of Hellcentrics comes in:

Hellcentrics works best when trained in a split routine – that means training certain muscle groups on certain days, e.g. Monday: Chest and Biceps; Tuesday: Legs; Thursday: Shoulders and Triceps; Friday: Back. If you don't have a training partner, there are still some exercises that you can do to test the concept, such as a Bicep Curl. Simply curl with one arm for eight reps and use your other arm to assist with the four Hellcentric reps. 

The concept of Hellcentrics was developed by strength coach and competitive bodybuilder Tom Fuller along with Michael Palmieri who founded the Institute of Sport Science and Athletic Conditioning.