I basically preach technique and rhythm as the basis of the your stroke, and to me, power is pointless until those two are mastered first. What most people will do is use power as a compensation for bad technique, thinking they can just muscle their way through to being a faster paddler. Sort of like putting a V8 in a Toyota Prius. It’s pointless to put that much power into a car that isn’t designed to accommodate it. The same is true with your stroke. Master the mechanics before you put any power into it. Then when you do add the power, do it in 10% increments, because what typically happens is, once you focus on the power, the technique goes out the window. This is a common mistake, so be very disciplined in maintaining your form as you increase the power.
One of the most efficient ways to add power is to drive the paddle deeper into the water at the start of the stroke. Just the act of driving the paddle deeper at the beginning, without any increase of muscle out put, will increase the power of your stroke. What you are basically doing is taking advantage of your body weight to create power, by brining it down onto the paddle. Just like a pole vaulter drives his pole into the ground to climb over it. When you add more muscle out put to this stage of the stoke it can become a very powerful tool in generating more speed.
Driving the paddle deeper ay the beginning of the stroke will require more hinging at the hips, which creates potential for more power integration into the stroke. Driving the hips forward while driving the paddle deeper is like a peanut butter and jelly sandwich, they just go together. The one creates opportunity for the other. In order to drive the paddle deeper you must hinge at the hips. Be careful at this point, because many people will just bend their knees to accommodate the deeper paddle but what happens is you loose the opportunity to drive the hips forward and create more momentum. To get the most out of the hip motion, think of pulling your lower hand and hip to meet each other at the exit point of the stroke.
One more way to add power is by driving that top shoulder into the handle of the paddle as you drive the paddle deeper. The top shoulder must be allowed to counter twist to the lower shoulder as it reaches forward. This will create the opportunity for the top shoulder to drive forward as the lower shoulder pulls back and unwinds from the stretch of the reach. It is important at this point to make sure that top arm is nearly straight as you drive that top shoulder into the handle. This will insure maximum energy is transferred into the paddle and none is lost in a bent arm. While driving forward with the shoulder, simultaneously you also want to drive the paddle down with that top hand, that is why you see the top elbow drop on the really good paddlers. What it also does is change the angle of the arm exiting the shoulder to a more leverage-able angle that will put less stress on the joint.
All of these techniques will by themselves create more power, but when reenforced with increased muscle out put, they will create a lot more forward momentum. As with any new skill you are trying to learn, be patient and allow your body to learn at it’s own pace, it may take longer to be patient, but the results will be worth it. Have fun.