In training, we have something called a “master cue.” The master cue is something that you give when your client is doing an exercise that will (hopefully) correct any form defects they are developing in the heat of the set (or just keep them going with good form). For the squat, a good master cue is “ass first, hip drive.” For the deadlift, an excellent one is “chest up, drive your heels through the floor.” The skill of cueing is important in training because the cue is the smallest effective bit of information you can possibly give the client and, ironically, can be the most useful. Why not explain it before the set? Well, you should. When the client is in the middle of a set, though, they can’t possibly pay attention to a technical description of the lift or look at you doing a demonstration. They don’t have the concentration capacity to apply 100%, look at you, understand, and consciously correct their form in the middle of a squat. The master cue gives them something they can process immediately and apply. Instead of spending 30 seconds explaining which muscles they should be feeling when, you give them something easy and digestible, something that gives them the “a-ha” that they can put in effect immediately. Think about it. When I say, “chest up, push the heels through the floor,” you can do that immediately. It’s simple. You don’t even need to think about it. Chances are, while you were sitting there your back straightened a little and your chest rose just as you read that. Compare that to me saying, “Your lumbar spine should be extended but not too much, don’t engage the back till it’s past your knees, keep your ass low to the ground at the start,” and you realize the importance of the master cue.
Not to say that all you need are cues. The technical description of a lift is very important too – it breeds understanding of the true biomechanics of the lift and helps you to coach yourself. The difference is that one deals with understanding and requires thought and a mental process to ingrain it as, “that lift,” whereas the other, the master cue, doesn’t require thought, it just requires action. It is saying, “do this,” as opposed to “when you set up like this, that should be as such.” And that is the skill of the master cue.
Now, the second half.
Something I realized at the gym today while doing my bench press was the common misunderstanding (even by trainers) of the phrase, “Slow descent, fast push.” To explain the true nature of what this phrase really means (and not the misconception), I have to start with the har
d stuff.
Something I learned in physics class a long time ago is that muscles have a spring constant (backed up here: http://ajpregu.physiology.org/content/278/6/R1661.full). What is a spring constant? In physics, a spring constant is the amount of force required to extend or compress a spring “x” distance. Since muscle is elastic in nature (to a point), it stores energy as it is extended and releases that energy (to a small but effective degree) to contract again.
Now, it’s only logical to remember that muscles are not perfect springs. They do, however fit the definition as materials that store elastic energy as they deform due to force.
But how does this relate to physiology and exercise? Cue the misused “slow down, fast up” cue. The good nature is there, but the meaning has been lost behind the cue.
When force is applied to muscle at rest, the stretch muscle engages unconsciously as a result of a motor nerve feedback loop. As the muscle stretches, it contracts to oppose the force being applied to it (to prevent damage to the skeletal system, nerves, and especially the muscle body itself). An excellent example of this is the jaw clasp test: holding the mouth slightly open and relaxed, ask a friend to (or do it yourself) tap with one finger, applying the force downwards, the top part of the chin, just below the lip (the mandibular protuberance). Chances are, unless there is something gravely wrong with you, your relaxed jaw will not bounce downwards, and the masseter muscles in your jaw will resist with just enough force to hold your jaw in almost the exact same position.
If you think about this, it’s an incredibly evolutionary advantageous adaptation. If muscles were strictly under somatic (voluntary) control, chances are, our ancestors would have had far more dislocation, sublaxation, and ligament tear injuries. The system favors muscle injuries over synovial and ligamentatious injuries. The advantage of a system that experiences solely muscle belly injuries (a pulled muscle) over damage to the connective tissues of the body is that muscle tissue is vascularized. Vascularized tissue (as opposed to avascular) is tissue that has blood vessels running through it, meaning it is fed by an active blood supply. Muscle is vascularized. Connective, ligamentatious, and cartilagineous tissue is avascular. What this means is that, being that the latter three types are only fed by proxy, by synovial fluid or other means, they are much less quick to heal than muscle tissue, and more likely to heal in a less-than-useful fashion. Muscle tissue, since it has excellent blood supply, heals very quickly, flushes waste very quickly, and, when healed actively (used in the fashion it is designed while healing), will heal with a minimum of scar tissue.
So now we know why and how the stretch reflex works, but where does it tie into the cue and the spring constant?
Contracted muscle tissue has a much higher spring constant than relaxed tissue, which means that contracted muscle stores a much higher percentage of the energy that gravity exerts on the weights in your hands as it descends than relaxed muscle. When you get to the bottom of the exercise, the energy stored in the muscles is at its maximum. This higher fraction of elastic energy already stored means that less energy will be required in ATP form to drive the weight up. As a side note: this does NOT make the exercise any easier on the muscle, nor will it affect gains in muscle mass – the amount of mechanical stress, that is, actual physical damage to the muscle tissue, remains the same for the exercise, and as such the muscle will be rebuilt and experience hypertrophy and hyperplasia to the same degree as with higher ATP energy required.
When a trainer tells you, “slow down, fast up,” know the true meaning of this cue. When you are going, “slow down,” (on what is called the eccentric phase of the rep) you should be focusing on storing the elastic energy in the muscle groups you are using. It’s a hard feeling to describe, but you’ll feel when you do it right, especially on the bench press. It manifests as a unique tightness in your muscles; it’s a really powerful feeling. You’ll feel in control, even with heavy weight, as opposed to the shaky feeling everyone’s experienced. The best friend of the powerful spring feeling is GOOD FORM.
Now, when you get to the bottom, DO NOT “let go.” What I mean by this is relaxing at the bottom of a rep. Again, you can feel this on the bench press the best. It’s when people get trapped under the bar. Save your rest for the top of the rep. If you “wait and relax” at the bottom of the rep, you release all the elastic energy stored in the descent, and force your muscles to do much more work going back up. It’s akin to learning the rowing stroke; you never “wait” at the catch, you drive as soon as you hit the “legs vertical” point. Think of the bottom of the rep as the “trigger.” You pull on that trigger and all that force builds up to the bang as you shoot the weight up. Yanking the trigger (by just letting the weight fall back down each rep) will throw the shot off and just ruin maybe even the set.
There you have it, the “true” meaning of “slow down, fast up.” What an anticlimactic ending.
As a side note, the reason the deadlift is so damn hard is because you come all the way to the floor, put the weight down, release all the elastic energy in your posterior chain, and pick it up again. What a mean, mean exercise.
Complete Fitness 