Faster eccentric reps are better than slow eccentrics for sports

As I have suspected for quite some time, it appears that slow eccentrics may negatively impact performance measures as found in a recent study published in JSCR (edit: In my opinion, this applies to novice athletes whom don’t know how to relax on the eccentric portion of sporting movements, experienced athletes can benefit from slow eccentrics but this usually consists of the supramaximal method).  If you have my jump program (comprehensive guide to the vertical jump), you would already have seen that I discuss how fast eccentric exercise can improve rate of force development.  There are a few vertical jump programs which emphasis performing the eccentric portion very slowly (good for tendon health, bad for performance), which is fine if you are in an anatomical adaptation phase (preparing the body for future training: anatomical adaptation). 

What did the authors do? [1]

• They took 30 college-aged males (average approximately 23) and split them into 3 groups:
  • 1 group performed a 2 second eccentric
  • 1 group performed a 4 second eccentric
  • 1 group performed a 6 second eccentric
  • The concentric portion was performed in 2 seconds for all groups with a 1 second pause
  • Exercise was a barbell smith machine squat with 4 sets x 6 repetitions (80-85% RM ) as the dosage
• Note:  The slow eccentric training cadence is very similar to the one promoted in the Triphasic System and The Flight System

What were the authors findings?

• They found all groups improved in average power in a squat jump protocol
• *The 6 second eccentric group suffered a reduction in peak velocity in the squat jump protocol
• The authors concluded that, “longer eccentric contraction times may negatively negatively impact explosive movements such as the vertical jump while shorter eccentric contractions may instigate greater amounts of soreness”[1].

Overall, I think this helps provide more evidence that slow eccentrics are probably not great for sports performance.  It is my hypothesis that performing the eccentric portion as rapidly as possible (while being safe), is much more sport specific and will translate much better into performance measures (fast eccentric exercise=greater RFD).

1.  Mike, Jonathan, Nathan Cole, Chris Herrera, Trisha Mclain, Len Kravitz, and Chad Kerksick. “The Effects of Eccentric Contraction Duration on Muscle Strength, Power Production, Vertical Jump and Soreness.” Journal of Strength and Conditioning Research (2016): 1. NSCA.