More than 25 years ago, I witnessed a demonstration using a large platform scale (called a force plate) that recorded changes in force. The subject, a 6’4”, 260-pound male, stood on the scale and performed an overhead press using a slow-to- increasingly- fast rhythm with a 60-pound barbell. At a slow speed, the signal on the attached oscilloscope moved in a smooth, steady motion and hovered close to 60 pounds. At maximum speed, however, the signal overshot the top and bottom of the screen. Freeze-frame analysis revealed that the barbell registered a force of over 200 pounds at the moment the repetition was initiated, and a force below zero for much of the remainder. In fact, the momentum of the barbell was lifting the subject’s arms.
Multiplying the force to which you expose a muscle or joint system by moving a weight quickly, without knowing the ‘breaking’ tolerance of that system, is neither wise nor safe. Likewise, strength training with a resistance that weighs little or nothing throughout most of its movement is not productive. The facts are undeniable. Yet most trainees use ‘fast’ movements and wonder why their results are slow at best or why the result they produce is the only one that could have been produced – injury.
It gets worse. Coaches, trainers and equipment manufacturers advocate methods that include ‘fast’ movements against resistance such as power-lifting and plyometrics, which borders on criminal malpractice.
Advocates of ‘explosive’ training rationalize their actions in two ways:
One, they believe that ‘fast’ movements automatically recruit stronger, more powerful muscle fibers, those required for athletic endeavors involving speed, strength and power. Research demonstrates, however, an orderly recruitment of muscle fibers according to effort intensity. When intensity is low – during the first repetitions of exercise – the brain recruits the weakest muscle fibers. As exercise intensity increases, the strongest fibers are asked to join in. Recruitment has nothing to do with speed.
Two, they believe that ‘fast’ movements in the gym result in ‘fast’ movements on the field. Not so. According to MedX inventor Arthur Jones, “How fast one moves while performing exercises for the purpose of building strength has absolutely nothing to do with how fast one can move while using the strength of those same muscles.” (1976)
Safe and effective training begins and ends with ‘slow’ training. A slow speed of movement better isolates muscles, works them through a greater range of motion and provides a safer alternative.
Its counterpart may one day prevent you from moving at all.
Author: Gary Bannister