A rapidly straightening of the leg immediately preceding ground contact (late swing phase of sprinting); when hamstring injury occurs most frequently; is connected with rising resistance to passive stretching of muscles:
Essays and commentary on a variety of topics including textbooks on strength training, debunking myths of strength training, and the like.
If you are training in such a fashion that your muscles don’t hurt doing the exercise, don’t bother. Quit.” (with a rising emote of anger, assertiveness). Arthur Jones.
Super – charged release of energy critical for dynamic sport, is neither cultivated with machines, nor training muscles until they “hurt”. Jones’ claim, training with barbell exercises are deficient; obscures the fact the human body is designed to generate power beyond intrinsic properties of muscles.
The smaller amplitude of movement in strength exercises involve less coordination, muscle relaxation skills; exercises which the derivative devotees promote: “… may provide a training stimulus that is as good as, if not better than, weightlifting movements that include the catch phase”;(1).
There is no basis for this in fact or fantasy.