When you're pumping your legs like a maniac in your indoor-cycling class, the weight-lifting session—which usually involves using light dumbbells towards the end of class—tends to feel like a break. That made us wonder: Does this "lifting" actually count as strength training? Similarly, do those on-bike push-ups come anywhere close to the real thing? We asked Joel Martin, assistant professor of exercise, fitness, and health promotion at George Mason University, to weigh in.
"It's probably not doing a whole lot for you" as far as traditional strength training goes, says Martin. Real strength training is usually defined by lifting weights so heavy that you can only perform one to five reps, he says. A little strength-training refresh: A weight you can lift one to five times mainly targets muscular strength, a weight you can lift eight to 12 times mainly targets muscular hypertrophy (which helps you look more toned), and a weight you can do 12+ times mainly targets muscular endurance (the thing that makes you better at lugging groceries up your fifth-floor walk-up), says Martin. Given that most weighted moves during class focus on light weights and enough reps to fill a song or two, relying on the weight-lifting session of your indoor-cycling class for strength training isn't your best bet. "You really want to choose a range in the middle—six to 10 reps at a challenging weight—to tap into both strength and endurance," says Martin. (Find the best weight lifting program for you.)
Still, on-the-bike lifting could count as strength training, as long as you find it challenging. Problem is, adding enough weight to make sure you're being challenged over the long haul is usually not an option. Flywheel, for one, offers 6 pounds max for the entire class—whether you count yourself as a bodybuilder or a beginner.
As for on-the-bike push-ups? "If you can do the move 50 times or more, then it's not even resistance training," says Martin. "It could build muscular endurance, but it won't make you stronger."
While you shouldn't ditch the bike—the mammoth number of calories burned in a 45-minute session is proof that it's worthwhile—adding weight training to your routine creates a more well-rounded workout. Martin recommends performing strengthening moves before class or devoting two or three days a week to 30- to 45-minute weight-lifting sessions.
When you're lifting, there's one super-important rule: Form trumps the amount of weight lifted. "If you start lifting too heavy, your form's going to become bad and that will lead to injury," says Martin. Aim to lift as much weight as you can while maintaining proper form, ideally hitting the sweet spot of six to 10 reps, he says. Want some serious inspo? See what really happens when women start lifting weights.