Power is one of two general physical skills that have equal requirements for both training and practice. Power is defined as “the ability of a muscular unit or combination of muscular units to apply maximum force in minimum time” (Glassman).
Power can be quantified using the equation:
force x distance
Work = Force X Distance.
It is the inclusion of the metric “time” that give us power. A standard pull up and a kipping pull up involve the same amount of “work” however the kipping pull up takes less time, thus more power is produced. The smaller the unit of time (faster speeds), the greater the quotient. That is, “as time goes down, power goes up” (Glassman). We can then conclude that increased speed leads to greater power, regardless of the load. By the same token, increased force provides for a greater dividend and naturally to an increased quotient, which means that gains in strength (the ability to apply force) should lead to improvements in power. Still, the most effective function of power combines strength and speed. Practically speaking, “How much can you move, and how fast can you move it?” (Rippetoe & Kilgore)
Developing power requires the application of vertical and horizontal movements wherein each individual repetition will “overcome resistances by a high speed of contraction” (Sefcik). Some of the most effective tools in the development of power are Olympic lifts such as the clean and jerk and the snatch. Here we find that simply pulling the weight is not enough. Successful completion of these movements demands that strength be coupled with bar speed, allowing the individual to move under the bar rather than muscling the weight into position. Lack of speed causes the movement of the bar to stop short of overhead, leading to a failed lift. Likewise no amount of speed can compensate for an inability to handle heavy loads, e.g. if it’s too heavy, moving it faster won’t likely get the bar overhead. Combined strength and speed, acquired through repeated exposure to the lifts, is mandatory for successful Olympic lifting. This is far more effective than the standard gym routine, say a bicep curl, because it increases the distance the weight is moved, the speed at which it is moved and how much weight can be moved.
Functional movements are unique in their ability to express power, from box jumps, in which body weight is being explosively moved, to thrusters which are nigh impossible without sufficient bar speed. Strength is important. Speed is essential. But power is the metric that we seek. We want our kids to move bigger loads, longer distances, FASTER! In the quest for fitness, power trumps.