Being short does have the disadvantage, but that should not make
you fail SBJ.
I find that apart from technique, strength training on the leg and
thigh muscles does make alot of different. Saying this, i get my
training in the gym. I used to detest going to gym, prefer to going
around the neighbour park for my exercise, i do regret not hitting
the gym earlier, and missing out on those monetary $$$... 
I used to go round the neighbour park for jogging, and some
stretching and chin-ups at the children playgrounds. The
improvement is little or not as fast as you hit the gym and let
external factors (weights, dumbbells, cycling, treadmills) helping
you and gaining confidents along the way.
I believe those clubfit gyms around the island cost about $2.50 per
entry.
