Hi Joceline
I’ve been using a chair for about 14 years now. To be honest, I don’t remember how long it took to build up strength. I know in the early days my deltoid muscles would ache, but that doesn’t happen now. People think I must have strong arms, but it’s not actually your arm muscles you use most - it’s your deltoids & shoulders that do most of the work. So building up those muscles will help. Something I use is a resistance band. Basically, it’s a stretchy piece of latex (physiotherapists use them a lot). I loop it round the back of my chair. Then, taking hold of either side by my chest, I push my arms out straight, which is a bit similar to pushing the chair.
Living in hilly Sheffield, I get plenty of practice on slopes. Getting a rigid chair, rather than folding, has helped a lot. But I’ve never once attempted to get the ramp for the train or taxi! They’re really steep, so the train guard/taxi driver always push (I never even ask, they just do it).
Keep practising, you’ll grow in strength and confidence.
Dan