Good-bye biceps curls on a BOSU and other circus-like moves. "Ten years ago it was trendy to stand on unstable surfaces while performing various weight-training exercises, but there's been clear evidence that this hinders your ability to create enough overload on your muscles," says Nick Tumminello, a personal training continuing education provider and owner of Performance University. While some studies have shown increased core muscle activity when lifting weights on a shaky surface, there are many core-specific methods (such as ball pikes or ball roll-outs) that more effectively work your midsection.
That doesn't mean you have to banish the blue disc: Unstable surfaces can be beneficial for rehabbing knee, ankle, or hip injuries or improving balance, so feel free to incorporate balance work on these types of surfaces between sets of resistance-training exercises, Tumminello adds.
