The following discussion is intended for people whose goals are exercise for health and general strength and muscle building. Those who exercise for power or Olympic lifting should use different techniques to train. Though goals may be different when training (and thus the approach should also be), we are all subject to the same biomechanical forces as explained in the discussion below.
Cadence refers to the rhythm at which you lift and lower a weight, or the second count it takes the weight to move from its start position to the top position (where the exercise is most contracted). Determining an appropriate cadence is important for a number of reasons. The slower you move a weight (to a certain degree), the more you increase the muscle tension, increasing the intensity of the exercise. (Ultimately, you always want to be making an exercise harder, in order make gains and reap maximum results.) What is also important to keep in mind is the ability to move the weight in a smooth, controlled manner.
The cadence should allow for a weight to move properly. That is, allowing for proper biomechanics, a slow enough motion as to avoid injury, and constant tension on the muscle throughout the Full Range of Motion (ROM).
At the beginning of a repetition, only enough muscular force should be generated to move the weight from the stretched position, so the weight moves slowly and in a controlled manner. Continuing through the repetition, only enough force needs to be produced to keep the weight moving slowly and smoothly. Once at the top (where the muscle is contracted), a brief 1–2 second hold may be included, followed by the deliberate and controlled reversal in direction of the movement, as the weight is lowered. Just as when lifting the weight, a slow, smooth and controlled motion should be used during the lowering stage. When approaching the bottom (or stretch) position, the weight should be lowered with control and ease, as if laying the weight down on top of a carton of eggs.
Smooth movement means of uniform consistency, without abruptly jerking or stopping. Slow movement refers to a velocity that permits smooth movement. Controlled movement means the motion could be stopped at any stage of the exercise without any bouncing.
Consequently, explosive movements are neither slow nor smooth since the action begins with an abrupt start and, if continued quickly, result in an abrupt stop at the top position. The same goes for dropping the weight quickly. Such movements cannot be controlled, as a bounce is unavoidable when the movement stops. Explosive movements increase the risk of injury and “unload” the muscle tension, reducing the effectiveness of the exercise at the very least.
Moving quickly does have its advantages: as velocity increases the magnitude of the impulse required to move a limb must also increase. (Impulse refers to the signal that travels along the length of a nerve fibre and is the means by which information is transmitted through the nervous system.) A greater impulse produces a greater activation of motor units, which stimulates a greater number of muscle fibres (e.g., fast-twitch fibres, which are responsible for greater strength and size). However, moving too quickly generates too much force and increases the risk of injury, and also generates momentum which takes the tension off the muscle.
Strength and size are developed because of these three aspects:
- Intensity (effort)
- Tension (strain of the weight)
- Metabolic work (measured in “time” and relative to the effort and strain)
Thus, quality of the tension is important and moving too quickly takes away some of that tension. The weight needs to be lifted as opposed to thrown.
Moreover, when moving a weight quickly, fatigue occurs because the muscle is quickly burning through its supply of ATP (the energy required to perform the movement). Thus, the muscles run out of energy before they become fully exhausted. When moving the weight more slowly, more muscle fibres are recruited to help with the movement and they are fully exhausted by the end of the exercise (this is the ultimate goal). However, moving a weight too slowly also has its drawbacks. Moving a weight too slowly reduces the rate of neuromuscular firing, and allows the body to reduce effort. This means less muscular force and less activation of fast-twitch fibres.
The ideal cadence must be slow enough to allow complete control throughout the full range of the entire movement without jerking, dropping or bouncing the weight; yet it should not be too slow. When moving the weight, simply think “smooth” and “control” throughout the entire exercise.
Always be consistent with your cadence as it is important to tracking your progress. In order to gauge improvement, you need to make sure you are always measuring the same parameters. Workouts should be standardized in order to do so. At New Element Training , we practice a cadence of 4 seconds up, a 2 second hold during the contracted position, and 4 seconds down (see Training Principles).
Brian D. Johnston, Prescribed Exercise, fifth edition (Bodyworx Publishing, Sudbury, ON, 2003).