If it weren’t for mirrors and women, many men wouldn’t bother building muscle.

But for all their bench presses and biceps curls, few guys see consistent results. The reason: all those bench presses and biceps curls. “To stimulate new growth, you need to mix things up every four to six weeks,” says champion weightlifter Jeremy Frisch. You don’t always have to radically alter your routine – the fix can be as simple as altering your grip or tempo – but if you’ve been doing the same moves for months, it’s time for a bigger change. Hit the refresh button with these five fast muscle moves.