Body by Science

[Guest guest]

Dave Flory wrote:

When I talk about momentum I'm talking about momentum of the weight.

This is achieved by accelerating the weight so it moves fast and keeps

on moving after the force is no longer being exerted by the lifter,

until gravity stops it. As in the snatch and the clean and jerk, and

not in the press. I think that's what Ed and McGuff mean, too.

Casler writes:

Hi ,

I often wonder why this argument (momentum) is used so often and often with

specious examples.

As I performed my Squats last night I contemplated why I was not flying off

the ground with my warm up weight of 140 x 30?

In most basic training actions like squats, deadlifts, benches, overhead

presses, etc, the biomechanics and leverages at lockout are such that

acceleration falls off. I won't supply the biomechanical details of this,

but when using normal heavy strength training loads (other than

intentionally LIGHT loads) the joint leverages and mechanics are such that

one will never experience inertial momentum unless a too light load is

overacclerated.

While it may be valuable to teach beginners proper form and loading, basing

ALL training on such a misinterpretation is not valuable, and even

counterproductive, since reasonable accelerations of loads in many actions

are what make them valuable and effective, and attempting to perform them

without this renders them less effective.

While there certainly may exist strength and conditioning actions like the

Clean where a load is accelerated quickly, unless you are using an

exceptionally light load, it travels very little on its own. Again this is

due to the reduced biomechanical efficiency at the top of the Clean compared

to the first and beginning of the second pulls.

Does acceleration cause the body to encounter load variance? Of course.

How else would you be able to curl a large weight without accelerating it to

and through the less mechanically effective midpoint? Reducing the

acceleration would then limit the load to what could be handled under the

limit of the midpoint, thus reducing training forces and loads throughout

the whole ROM.

Some of the perpetuation of this " momentum " edict was propagated by the

Cammed Machine promoters/proponents. This was due to the fact that the

" CAM " was actually a " reverse engineering " of natural accelerations

interacting with the strength curve, and for the CAM to function, all

non-cam produced force variations due to accelerations needed to be reduced

to the point of elimination.

So now we have machine based philosophy being espoused to apply to free

weights which " REQUIRE " various degrees of accelerations to accommodate the

force and biomechanical properties of each exercise or lift.

The " anti-momentum " edicts are not applicable to well planned and understood

training actions.

Regards,

Casler

TRI-VECTOR 3-D Force Systems

Century City, CA