It's a great technique and I improved vastly, but I've spent maybe between 100 and 200 hours practising (rough estimate) and I still can only swim between 50 and 100 m before I run out of breath.
And I'm still sinking like a rock. There's an exercise we do, exhale and submerge, and sit on the bottom of the pool. Every instructor does it with some effort, so much is their buoyancy, but that's the one where I shine.
And I know my problem, every instructor tells me - I have to be more relaxed. Well, except that I can not tell myself to relax and just do it - somehow it's a long and slow process, and so far I don't see the way to learn 'relaxing' quickly and effortlessly.
There was no quick fix, I just swam twice a week for years until (a) my muscles became more used to the exercise and (b) I learnt to relax and enjoy it.
I've found that not kicking at all and focussing purely on the arm movements helped a lot.
In fact, I swam 2km yesterday without kicking at all.
I'm trying to kick as little as I possibly can, as in 2-beat kick. But I don't have years of practise, so if I try to swim without kicking at all, I'd just start sinking very, very soon. :)
Swimming skill and the learning ability somehow does not correlate with things like fitness, strength, flexibility or even coordination - I practise a martial art and weight training, my body is much better developed compared to an average person ... ON LAND. But in the water - everyone, no matter how old or large or stiff - progresses faster and swims better ... that's frustrating and motivating at the same time.
