A mid-round tuneup will help you finish strong: How many times have you shot a personal best on the front nine only to come limping in over the final stretch of holes? Or maybe you found your groove around the seventh hole but lost it by the 13th."It could be a motor-programming issue," says Golf Digest Fitness Advisor Ralph Simpson, a former trainer on the PGA Tour. "Whether it's a specific weakness or you're simply getting fatigued, sometimes your muscles won't do what they're supposed to do, and the result is a bad golf swing."For example: Short putts typically become harder as the round grows longer. Nervousness and pressure aren't the only reasons. As your lower-body muscles tire, it becomes difficult to keep still while you putt."Sometimes, all your muscles need is a wake-up call to play better," he says.As you're making the turn, or any time you're waiting to play, Simpson suggests that you give your body a tuneup to help correct these common swing flaws. It only takes five or six reps of any of these moves to get your muscles working correctly so you can continue hitting good shots.