Fiber Type/Biomechanics vs Max Strength/Force Production

This is one that I have been contemplating for a while now that I thought would make for interesting conversation.

Consider Carl Lewis and Ben Johnson:

Taking in to account the strength levels, of Johnson, that have been well documented here on Charlie’s site, it is safe to say that he possesed very high levels of strength/force production.

Going by aesthetics alone, not having any hard data of my own, Lewis did not appear to have near the strength/force prodution values that Johnson did.

I will continue under the assumption that the RFD of both athletes was comparable.

It is a fact that tendon inserstion, on two levers, places a large role in mechanical advantage. Thereby decreasing the length of the moment arm, allowing for greater force production. For example: the more distal the insertion point of the biceps tendon onto the forearm, the greater load that can be lifted in the biceps curl.

It is also a fact that individuals fortunate enough to be born fast twitch dominant will tend to excel at power development sports. I will also assume that both sprinters posses a high percentage of Type II fibers.

So I contend that Lewis has a phenomenal percentage of fast twitch fibers in conjuction with an optimal biomechanical structure (i.e., optimal lever length/tendon insertions) which allowed him to excel in the sprints/long jump and pose serious competition to the otherwise superior strength/force production of Johnson.


James Smith

James, a recent article by Rahmani, Locatelli and Lacour (EJAP online - not yet in press but available in ‘online first’ section of the journal) looked at a similar idea comparing Italian and Senegalese sprinters. Basically they showed the italian athletes had more power and likely greater percentage of FT muscle but only ran the same 100m times due to being biomechanically disadvantaged as compared to the Senegalse athletes(ie the Italians had relatively shorter legs and greater lower leg masss).

Contrasting body types thus can produce similar performances on the the track due to sprinting being dependant on several factors as you discuss.

For the record I reckon Ben would have had a much greater RFD than Carl in most standard tests though possibily during ground contact in sprinting it would have been similar…

Rossa, after further review, and with respect to standard testing procedures for RFD (i.e., vertical, standing long jump) I wonder how the two athletes would have compared. Considering Lewis’ outstanding performance in the long jump. What are your thoughts?

Acknowledging that running speed plays a significant role in the long jump, a great long jumper must still have high RFD capabilities. In contrast to the great long jumpers who do/did not posses outstanding sprinting speed (i.e., Powell, Beamon). Thus, RFD is the constant in great jumpers, not great sprinting speed.

Back to comparing the two athlete’s RFD testing. Were you referring to tests other than vert, and standing long jump?

As far as the Olympic lifts go, we both know who would have been the superior.

James Smith

James, Standing vertical and long jumps are not real tests of RFD, my understanding is 2 athletes of quite different RFDs can achieve the same performances in VJ or SLJ provided they have the same take off velocity. Rate of force development differences may mean one athlete could take twice as long to achieve the same velocity and the thus the same jump performance… Testing on a force plate or isometric work using a force transducer are examples where you can get actual measurement of the force time characteristics of a performance.

w.r.t Ben vs Carl on SLJ or VJ I’m not sure would be interesting to see though not sure that ben ever tested that stuff.

Rossa, point taken on the RFD variables, with respect to vert performance.

To add to your reference, strength can compensate for lack of RFD, or vice versa.

Incidentally, what motor skill do you feel the vert, and standing long jump display?

In my view the vert and standing long jump display a combination of strength and RFD. In reference to Carl and Ben, if they both tested the same in these two tests, then it would be prudent to state that Lewis had a higher RFD value, whereas Johnson had greater strength levels.

In Science and Practice of Strength Training, Zatsiorsky defines RFD and explosive strength as one in the same.

James Smith

jman, as far as sprinting at the higher levels rate of relaxation is probably more important than rate of force development once out of the early acceleration phase.

dcw23, what are your thoughts on the vert/standing longjump motor requirements?

Do you agree with Rossa in that the vert/SLJ do not adequately display/exhibit RFD values?

I am in agreement with Rossa as far as force plates and other force measuring devices (i.e., Tendo unit) go, in that they are the most accurate way to assess RFD. However, I still feel that the vert/SLJ are still adequate tests of RFD.

James Smith