WARNING: This program is incredibly anabolic, and along with this comes an unusual level of intensity. An advanced routine that will leave you sore and drained at least for a day or two after the session, when you use real eccentrics, you'll know it. It is strongly recommended that you follow the M&F recovery guide discussed in this issue. If you're up to the challenge, you'll experience some of the greatest gains possible.

The Sexy Science of Muscle Growth

The reason we're so interested in eccentrics is because research shows that they're so beneficial for growth and strength1,2. Emphasis on this portion of the rep induce the microtrauma to our muscle fibers that stimulates our body to repair and build bigger and stronger than they were before3. Unfortunately, as a corollary they also cause a lot of delayed onset muscle soreness (DOMS)4,5.

This isn't necessarily bad news, as this may also be correlated with muscle growth. It would seem that the simple idea of training for soreness has some merit afterall. Interestingly, the speed of the forced eccentric movement (not a voluntary slowing of the weight on the way down) is directly correlated with the growth and strength potential, as well as DOMS6,7. Within reason, the faster the negative, the better it is for us.

Among the anabolic properties of heavy eccentric training is an increase in muscle IGF-1 levels8. The latter is the prominent growth factor responsible for muscle growth and repair, more of which is a very good thing. Additionally, there is a reduction in the production of the negative growth factor myostatin9. You may have heard a lot about this recently as myostatin actually inhibits muscle growth, and its control has spawned a new breed of anabolic drugs (one of which is likely going to be commercially available quite soon). In summary, eccentric training gives us more of what we want, and less of what we don't, all of which favors hypertrophy.

Sexy Strength

For those of you more interested in the strength side of the equation, eccentrics are still ideal. The reason is that we're taking advantage of an otherwise unused portion of the repetition, and the very high forces involved during this phase stimulate the nervous system to adapt and grow (nerve cells grow from strength training too)10,11.

Bonus: Injury Reduction

Another critical component of athletic performance is eccentric strength. This is largely used for decelerating and changing direction, which are key times for injury. Consistent with this, brand new research has shown that eccentric strength decreases during athletic match play, and this is correlated with elevated injury risk12. This is because our muscle handles less of the load, leaving our joints to take more of the forces. This could lead to excessive load bearing during stopping or directional changes, which is often how undesirable tissue trauma occurs. By training this portion of the movement, we can increase eccentric strength and potentially protect against athletic injury.


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2 Eur J Appl Physiol. 2008 Feb;102(3):271-81.

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4 Am J Phys Med Rehabil. 2002 Nov;81(11 Suppl):S52-69.

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6 Eur J Appl Physiol. 2003 Aug;89(6):578-86.

7 J Appl Physiol. 2005 May;98(5):1768-76.

8 J Physiol. 2008 Nov 15;586(Pt 22):5549-60.

9 Eur J Appl Physiol. 2007 Nov;101(4):427-36.

10 Eur J Appl Physiol. 2003 Aug;89(6):570-7.

11 Sports Med. 2006;36(2):133-49.

12 J Athl Train. 2009 Mar-Apr;44(2):180-4.