Starting Strength, 3rd Edition - Mark Rippetoe [116]
Power, Force Production, and Velocity
Understanding power and its relationship to force production and velocity is essential to understanding how to effectively train this capacity and why the power clean works so well at doing so. Figure 6-5 shows the velocity-power graph. The dashed line represents bar velocity – very high when the load is light, and slowing down to a stop as the load approaches maximum. The dashed line represents power production – the force displayed quickly.
Figure 6-5. The velocity-power graph. The dashed line represents velocity, and the solid line represents power output. Peak power occurs at approximately 30% of maximal isometric force and 30% of maximal movement velocity. This would equate to 50–80% of 1RM, depending on the exercise. “Strength” movements are those that are limited by strength, such as the squat, press, deadlift, or similar exercises. “Power” movements are those limited by power output, such as the snatch, jerk, clean, or other similar exercises. From Practical Programming for Strength Training, Second Edition, 2009, The Aasgaard Company.
Power is low on the left side of the graph, at very light weights, because light weights don’t require much force to make them move fast. They move fast easily because the weight is light. Power is also low on the right side of the graph, where the weights get very heavy, because a very heavy weight is hard to move fast. Remember: power requires velocity. Power peaks in the range of 50–75% of 1RM, where a moderately heavy weight can still be moved relatively fast. The range represents differences in the nature of the various exercises, whether the exercise is primarily an upper-body or lower-body movement, and the skill, strength, experience, and sex of the individual athlete. (Women can typically use a higher percentage of 1RM explosively than men can.) This range (50–75% of 1RM) is also where the power clean usually falls as a percentage of the deadlift.
The popular Westside Dynamic Effort method, developed by Louie Simmons, trains power production by using weights in the range of 50–75% of max in the squat, bench press, and deadlift with an emphasis on maximum acceleration during the reps. Louie has essentially figured out a way to train the squat, bench, and deadlift as if they were Olympic lifts, by training them with weights that can be used at the velocity that produces maximum power.
A logical question, the converse of our earlier one, might be: why do we need to squat and deadlift to develop strength at slow speeds if we are training for power? Both types of training are necessary and each type contributes to the development of the other. Again, a man with a 500-pound deadlift can clean more than a man with a 200-pound deadlift because of the great difference in the ability to produce force. But between two men who both deadlift 500 pounds, the one moving it faster is producing more force, is therefore stronger, and is training in a way that teaches his muscles and nervous system to produce even more force. Training faster with a given weight requires more force production because acceleration requires force. And when the ability to produce force goes up, heavier weights can be lifted. This is why the power clean makes the deadlift go up and why the deadlift contributes to the power clean.
The weight that can be used for a heavy power clean, for most athletes, is the correct weight to use to improve