Pump It Up! (Your Exercise Ball)

My exercise ball before I cut the umbilical cord.

Exercise balls - or Swiss balls, stability balls, or balance balls, whatever you like to call ‘em - are great for improving core strength and stability. They come in a variety of sizes, typically ranging from 45 to 85cm. According to NASM, the National Academy of Sports Medicine, the size ball you should use is determined by your height:

45cm = under 5'
55cm = 5' to 5' 7"
65cm = 5' 8" to 6'
75cm = over 6'

So if you are in the market for a ball, be sure to choose accordingly. And if you go to the gym, check to see if the ball is labeled with the diameter you need.

Let’s say you just unboxed your new ball and you need to inflate it. How do you know that you put enough air in it? Or if you put too much? The general rules are: 1) inflate to the proper diameter, and 2) make sure the ball has a little “give”.

Okay, first question: How do I know that I inflated the ball to the right diameter? There are a few ways to determine this. Some ball manufacturers actually include a little “measurement belt” that you can put around the diameter of the ball as it more fully inflates. Once the belt is snug, you’ve reached the right diameter.

“But wait Jane, I don’t have one of those.” Did you lose it? No worries, I’m not judging. Here’s what you do:

First, find a couple of boxes. They should be at least a little taller than half of your ball’s ideal diameter. (For example, 23 cm tall for a 55cm ball.) Next, find a measuring tape. place one edge of the tape on the side of the first box, then place the other edge at the appropriate diameter. Inflate the ball until the edges of the ball are snug up against the boxes.

Here I set up two boxes 55cm apart; I filled the ball until it fit snugly inbetween.

And that’s it! Now, perform one final check by sitting on the ball with your feet flat on the ground. Are your knees at 90 degrees? If so, you’re good to go! If not, you may need to adjust the size of the ball by inflating or deflating. Worst case, you may need a different size ball - but hopefully not!

And make sure that the ball has a little give. In my experience it can be tough to overinflate the ball, but if you go to sit on it and the dang thing shoots out from underneath you, well then, time to take some of the air out.

On the left, my exercise ball was a little low; you can see how my butt is slightly lower than my knees. On the right, I added a little air. You can see how I’m sitting taller on the ball and my knees are closer to 90 degrees.

Remember that exercise balls slowly deflate over time—you may need to “top off” occasionally. Above you can see me sitting on my 55cm ball before and after inflation. See how I’m sitting a little taller, and my knees are more at 90 degrees on the right? That’s what you want my friends!

So that’s it! Now that you’ve got your ball set up, you’re ready to rock! Do you need some exercise ideas? Click here for a workout featuring all exercise ball moves. You can also go to my YouTube channel and search for “exercise ball” for more workouts!