What ball should I buy?
You shouldn't need to spend more than $20/£15 and don't worry about any accessories or fancy qualities. All balls are about 99% the same......just buy one.
What size ball to buy
- If you're 6' or taller, buy a 75cm diameter ball
- If you're under 6' buy a 65cm diameter ball
Over time having a second ball of a different size can be good to challenge yourself, although the above should meet most people's needs.
How much should I inflate the ball?
I'm not sure there is such a thing, but you want the ball to have enough air in it that it doesn't completely collapse when you put your weight into.
But conversely, you don't want to have so much air in it that it has no give when you put weight into.
A good general test would be to inflate the ball and when you sit on it, you sink down about 6"-12", but no more.
There's going to be a little trial and error to find out what 'feels right', just think that you want enough resistant from the ball that it'll push back against your actions, but not so soft that it collapses under your weight.
What clothes to wear
- Wear a rash-guard: a t-shirt will likely get twisted up against the ball, or will ride up as you move. Adjusting it becomes annoying. Going to shirtless is OK now and again, although when you get really sweaty, you can lose a lot of traction on the ball.....plus you'll need to clean it far more often.
- Wear close fitting no gi shorts or board shorts that have some stretch: normal sports shorts, or loose fitting board shorts will ride up the legs as you move and this gets annoying very quickly. Shorts that have no stretch will limit your movement.....that's no bueno. Gi pants are OK (although some find they get twisted against the ball), but I'd avoid leggings as you'll lose some traction on the knees which can be important for some drills.