Who needs to work out FOR Halloween when you can work out ON Halloween? If you’re ready to channel your inner Jane Fonda and relive your neon-clad, leg-warmer-wearing, Jazzercise glory days, then get excited: we have a bevvy of inspiration. The ’80s workout getup is basically the best, most nostalgic, easiest costume to pull off . . . plus it’s just so damn fun. Get your girls together and start layering on the spandex.