The Pros of Concentric power training – getting more with less
Quick lesson; when resistance training, the shortening of a muscle under a load is called the concentric phase. The lengthening of a muscle under a load is called the eccentric phase (pronounced EEEsentric). Think of an arm curl with a dumbbell; the “curling” up of the dumbbell is the concentric phase of the biceps muscle. The lowering of the dumbbell is the eccentric phase of the biceps muscle.
Most functional movements are concentric. Most aerobic activity is concentric; walking, running, cycling, rowing - all concentric. Examples of prominent eccentric movements would be big mogul skiing and walking down stairs, both of which can be hard on knees. While eccentric movements have their own validities and applications, we can learn a thing or two from the Olympic lifting community about concentric strength training.
- An eccentric movement can handle a greater load than its concentric counterpart, so it takes more weight to reach peak power
- Most muscle soreness and tissue damage occurs during the eccentric phase
- While eccentric strength movements do elicit improvements in muscle strength and size, they are location and speed specific. They do not translate to functional application
- Eccentric fatigue compromises the quality/intensity of the concentric work
- Concentric strength training has shorter recovery time and less muscle soreness, allowing for higher quality/intensity of work and more training sessions
Sitting down is pretty easy. It is eccentric so you can handle more load (which is, in this case, you) and gravity is offering you encouragement along the way. Once seated, getting up may be another matter. This move is concentric and gravity is working against the load (yep, still you). Furthermore, any extra fat mass that you are carrying is not contributing to the movement because it is not muscle so it is also working against you. So scoot out to the edge of your chair with your feet planted parallel, shoulder width apart. Sit up tall, with your chest up and chin level. Extend your arms out in front of you for counter balance. Tilt forward from your hips, without flexing your spine, until your shoulders are over your ankles. Now tighten your stomach and drive up through your heels to a standing position. Did you make it? Congratulations, you have just performed a concentric squat. In a traditional squat movement you would begin from a standing position and lower yourself to chair height before changing direction and coming back up. In that scenario the eccentric phase is storing potential energy, like a spring, in what is known as the Stretch-Shortening Cycle (SSC). As you can see we are not doing that ‘cause in the real world you won’t always be afforded that luxury and we are all athletes in the real world. Try another one, again setting yourself up with the above postural cues. Try a third. Rest as much as you like in between repetitions if you need to. Do this every day until you can perform a set of ten repetitions. If you can already do ten repetitions, add weight! Hold a five pound dumbbell at your chest; or a medicine ball, or a water melon, or a grandkid (make sure they sign a waiver). As you press up off the chair push your dumbbell up overhead in one single, integrated movement. This is a Squat Press.
So, you have mastered and engrained the pattern/form. Then you have built a base of strength. Now it is time to become powerful. Power, somewhat loosely speaking, is strength X speed. Power has significantly more functional application than stand-alone strength. The idea is to take your form and strength and accelerate it, making it both explosive and powerful. The key to making this type of training effective and safe is to isolate the concentric phase as much as possible.
Case in point – the Power Squat Press
Ok, so back at your chair with your dumbbell held at your chest you are going to build power by accelerating the Squat Press movement during the drive phase. This power is a whole body affair generating from the ground up from the heels through the legs, butt, core, back, shoulders, arms and finger tips through whatever you are holding. The very best way to expend this energy in the concentric phase with no eccentric repercussion is to release whatever you are holding at the end of the movement, kind of like a two handed shot putt. You can practice this with a bean bag, or a medicine ball. Watermelon? not so much; dumbbell? Definitely not. Grandkid? Get the waiver notarized.