Your body wasn't designed to rest on its butt for nine hours a day, no matter how ergonomic your office chair is. So why assume the 90-degree position in the gym, too? Smarter training means working out on your feet, not on a bench. It means engaging your whole body—take the humble push-up, a three-for-one cardio-, mobility-, and strength-building exercise. Which is why the smarter home gym starts not with a stable of shiny metal machines but with open space; a rubber or wood floor is best. What comes next is a collection of simple, no-BS essentials that we call the fitness tools of the future—though you may recognize some of them as updates of the fitness tools of the past. Climb a rope, scale a ladder, swing a club, catch a ball, roll a wheel. Your (firmer) ass will thank you for getting off it.