Personal trainer Janel Bilal shows the proper way to do biceps curls. There should be no rotation of the wrists or movement in the lower back.
The weight room can be a confusing place for gym-goers. Often armed with too little information about how to properly handle weight and cable machines and free weights, they are ripe for making blunders -- and it can cost them, leading to major and minor injuries. We asked five Southern California trainers: What's the worst mistake you've seen people make in the weight room?