The best known way to increase potentiation (to enhance or increase the effect of force output) is to utilize proper activity prior to the actual lifting of the weight. In Roger Enoka’s book, “Neuromechanics of Human Movement,” he describes the effect of post tetantic potentiation as “a twitch elicited in a resting muscle does not represent the maximal twitch.” (pg. 391) According to Enoka, muscular twitch force is maximal following a brief tetanus or stimulation. One study showed an increase in strength after tetanus in the realm of 5% to 140%. I believe the discrepancy in strength increase is based off the muscle fiber make up of the subjects studied. Fast twitch muscle fibers tend to ellicit a greater potentiation response than do slow twitch fibers. Therefore, slow twitch individuals (distance runners) may not respond to eccentric hook training as well as fast twitch individuals (shot putters).
As you can see in the video (Eccentric Hook Video), the hooks provide a strong muscular contraction on the eccentric portion of the lift. When the hooks are released from the bar a more powerful muscular contraction is achieved due to the effects of post-tetantic potentiation. There are even further benefits to training with the hooks. Higher threshold motor units are recruited and thus trained/fatigued. Vladimir Zatsiorsky, sport scientist at Penn State and author of “Science and Practice of Strength Training”, has made it clear that to reap the benefits of high threshold units, they MUST be trained and fatigued (pg. 86). Hooks train high threshold motor units, they fatigue the high MU’s and dramatically improve maximal strength.
Please Note: These strength gains are related primarily to maximal strength. Shot putters or fast twitch fiber type may respond well to this training but this does not mean this training is necessary for their sport. Long Jumpers experience large eccentric forces, so it may work at times for them but for individuals such as shot putters and discus throwers and hammer throwers, special strength takes priority over maximal strength.
