Your yoga ball, or exercise ball, only works well if air is sealed in. Your workout is unsafe and ineffective if you have a deflating yoga ball. But an overinflated ball is also unsafe, so follow the manufacturer's guidelines for proper inflation of your yoga ball and then plug it tight before you begin your workout.
Select the right-sized exercise ball for your height. Use the manufacturer's height recommendations as a starting point.
Remove the plug from the yoga ball by using your fingers or by sliding a plug-puller, or the edge of a quarter, underneath the plug. Wiggle or twist the plug back and forth if it does not come out easily.
Insert the end of the air pump into the hole. Inflate the yoga ball. Use a tape measure to determine when the ball measures the diameter printed on the ball or box, and stop inflating it at that point.
Sit and position the ball on the floor between your legs. Place one hand on the end of the pump. Straighten the first finger of your opposite hand. Quickly pull the air pump out of the ball and place your finger over the hole.
Set down the air pump. Hold on to the plug in that hand. Position the end of the plug close to your finger covering the ball's hole.
Slide the end of the plug underneath your finger as you quickly uncover the hole and push the plug into the ball. Press on the plug until it lies flat with the surface of the ball or slightly below the surface.
Squeeze the ball gently between your legs and feel for any air leaking from the plug.
