I've been skating for a total of about 13.5 years. I still cannot center spins consistently, nor can I check turns consistently, despite the best efforts of myself and a number of good coaches.
I've recently come to the conclusion that it is a matter of control and repeatability. In other words, if the motion always goes the same way, one can make consistent corrections to that motion to solve the problem. But it doesn't - sometimes I lean one way, sometimes the other, and so on. And as far as I can tell, repeatability is a matter of stabilization and strength. If you stiffen your body sufficiently, especially in your core, you can control its motions, and always do the same thing, making repeatable corrections possible. If, on the other hand, you stay too loose, then motions are inconsistent, and are therefore uncorrectable.
I've tried stiffening my body. But I'm not very strong. I can only do several sit-ups or push-ups, and can't do a pull-up at all. I no longer have the strength to get into or out of shoot-the-duck, though that is partly flexibility. Lifting 30 pounds is a strain. So a few weeks ago, I started strength training in a gym. I've hardly done any strength training before, and have a long ways to go. Progress is slow (I'm about 60), and I'm sure it will take somewhere between a few months and a few years.
I think I've wasted too much time in general trying to finesse things, and figure out tricks to make things work. I suspect that with strength, the need for finesse and tricks at least partly disappears. I should cut back on skate practice, until I have the strength to do things right, because it can't get much of anywhere until I do. If I'm right, coaches should have advised me to do this long ago.
If I'm right, it helps explain why athletic kids learn things like skating so quickly. They already do so much running and jumping and other athletic things, that they have strong muscles, relative to their body weights, and are able to stabilize themselves. They need little finesse and trickery, because they have the strength.
I've been working primarily on
1. Lower core (abdominal) muscles, using
A. Leg presses, with both one and two legs
B. Rotating the spine about the waist, in alternate directions, with and without weights
2. Upper core (shoulder height) muscles, using
A. Assisted pull-ups
B. Lifting hand-weights in all directions
C. Rotating the spine at shoulder height
3. Middle core muscles. I'm having some trouble figuring out how to strengthen those, but so far I have
A. Using a weight machine on which I sit and push up and back against weight, contact point below the neck
B. Using a weight machine on which I sit and pull down and forward against weight, contact point below the shoulders
C. Shrugging alternate shoulders up and down, while holding hand weights.
D. Leg raises, in prone and supine position. I can't bring the leg all the way up, because of flexibility, but I do what I can.
A. Twisting about the spine with a stretch cord under one foot, and the other end in the opposite hand.
5. Lifting things from the floor.
A. I've just finished moving all my stuff out of my old place to live, mostly into storage. Now I need to gradually sort the stuff, and bring some of it to my new place.
B. Maybe I should practice lifting other weights too, now that the pressure from the move is over.
I am following the advice of a physical trainer - that
1. To build strength, one should repeat an exercise to the point of "failure", where the muscles are physically unable to do another rep.
2. I am doing both high repetition, low weight, and low repetition, high weight versions, in the same session. E.g., do an upper body exercise in the high weight, low rep version, then a lower body exercise, than a middle body exercise. Stretch. Then do them all again in low weight, high rep versions. Stretch again.
3. To build strength, one must feel sore after the exercise session. The soreness should last into at least the start of the next day. I probably paid too much attention to over-cautious advice warning against DOMS (Delayed Onset Muscle Soreness).
4. That one must stretch all the muscles that you strengthen, after the exercise, because strengthening shortens muscles.
5. Stretch often, 2 or more times a day. I definitely paid too much attention to over-cautious advice against stretching too often, which shouldn't apply to people like me whose muscles generally return to prior length in a day or less, and are unlikely to over-stretch ligaments and joint capsules, because my short muscles limit my range of motion to the point where ligaments and capsules aren't a problem.
My questions are:
1. Is my basic premise correct? Is repeatability and correctability best attained through muscle stabilization, and does one need a fair amount of core strength to achieve it?
2. Have I missed anything important? Other necessary exercises to obtain stabilization strength?
3. Since this will take a lot of time, how far do I need to go? E.g.,
A. Clearly, to do decent sit spins, one must be able to both quickly and slowly go deep down and back up on one leg. So I will need to be able to do a fair number (8-10???) of full body weight single leg presses, and therefore at least 200% of my full body weight on double leg presses. Is that enough for good skating-related muscle stabilization? (One obviously needs considerably more for good jumps, but I'll leave that out for now.)
B. Pull-ups clearly aren't part of skating, but they help with upper core muscle strength. For skating stabilization, should I be able to pull up against 70% of my weight? 100%?
C. Fit males often lift similar height trim females, "on the threshold", and in social dance. A reasonably trim lady my height (5'4") might weight 100 pounds or a little more. Is 100 pound lift a good measure for good skating-related muscle stabilization for me?
D. Other good measures?