I have never been a fan of this fad, but I know that some people here are fans. I just figured that I'd pass on this nugget of science.

Recently a study was done comparing trunk muscle activity during stability ball and free weight exercises when exercises including squats and deadlifts were performed either with or without the use of a stability ball. The researchers found no significant differences in the rectus abdominus or external oblique during any of the exercises.

The researchers concluded that the activity of the trunk muscles during squats and deadlifts is greater or equal to that which is produced during the stability ball exercises.

Here is an excerpt from the authors:

"It appears that stability ball exercises may not provide a sufficient stimulus for increasing muscular strength or hypertrophy; consequently, the role of stability ball exercises in strength and conditioning programs is questioned."

See, Trunk Muscle Activity During Stability Ball and Free Weight Exercises. Nuzzo, James L et al. Journal of strength and conditioning research: the research journal of the NSCA, ISSN 1064-8011, Vol. 22, Nº. 1, 2008 , pgs. 95-102.

I heard that it can cause all kinds of knee and joint problems - that they aren't made to handle loads and stabilize like that at the same time...  not sure how much truth was in it but it made sense to me. 

Grab the day by the balls and make it your b!tch

I've found that no amount of information or reserach can correct stupidity. It will probably take an injury before someone realizes, "hey, maybe that was a stupid thing to do?

What kind of idiot says, "here, load this bar up with 100 pounds and stand on that BALL?"

What kind of effing idiot says "OKAY"?

I could see MAYBE doing some squats on one of those half balls that are at least flat on the bottom, so there is some stability to the ball itself so it doesn't roll out from underneath you, but i give that a BIG MAYBE. At the very least just use some DB's or something instead of an olympic bar, so you can easily get rid of the weight if need be and not risk it falling on you.

Even this would be a billion times better:

 love the bosu ball, and I think both have their place in a workout, but the 1st pic is just plain stoopid

Every time I look at that picture I imagine him falling forward, and landing across the ball and the bar landing on the back of his neck!!!

And look, I found a YT video

Epic Fail at :45

heehee