A stirrup pump or hand pump is recommended to inflate balls, as compressor pumps or airline pumps can lead to over inflation.
In order to get the needle into the ball, dampen the needle with water.
The valve for the ball is situated in the main panel, but on the match balls the valve is hidden in the seam.
Make sure there is enough space for the needle to go all the way in without touching the facing inside wall of the ball. Not doing this may puncture the ball from the inside. Hold the neck of the valve with two fingers. Pinch it, wet the needle and slide it in.
It also helps to grip the entry point from underneath to make sure the needle goes all the way in.
NOTE: When pumping is initiated, it is normal to hear a hissing noise, indicating that air is escaping. This is air trapped between the bladder and outer panels, moving through small holes at each end of the ball's outer surface. As you continue to inflate the bladder and the ball takes shape, the hissing noise will quiet.
Inflate ball to 9.5 psi
Check out this video to see it done by a professional https://www.youtube.com/watch?v=2myIM4sknoM
