By now, you probably know that strength training is a necessity if you're trying to lose weight. Just in case you needed one more reason to believe it, Autumn Calabrese, Beachbody Super Trainer and creator of 80-Day Obsession, confirms this to be true.
"Muscle requires more fuel to function than fat does, so you want lean muscle," Autumn told POPSUGAR. "In order to build lean muscle, you have to lift weights a little bit. You need to not be afraid to lift."
OK, noted. But how do you know what the right number of reps is? If your goal is to lose weight and tone your body, Autumn recommends shifting back and forth between 2x15 and 3x10 (that's two sets of 15 reps and three sets of 10 reps). "The 2x15 is the more cardio, strength-training zone where your heart rate is going to stay up, your muscles are going to burn, and you're using a little bit lighter weight," she explained. "But I like alternating that with a 3x10 because we can't be afraid to build a little bit of lean muscle."
Autumn says alternating between these two formulas will give you the body you're hoping for — sculpted, toned, and strong. That's why she switches back and forth between these two in her 80-Day Obsession program. The goal is to simultaneously build lean muscle and burn fat.
You might see or hear some women working with very low weights and a really high rep range between 20 and 30. This is said to prevent you from "bulking" up, but Autumn doesn't really agree with that philosophy. "I don't particularly care for that," she said. "I think it leaves a lot of room for injury. When you do anything for 30 reps, the fatigue is going to set in and it's easier to let your form go."
Check out Autumn in action! Here's a 10-minute flat-belly video workout featuring some of her favorite core moves.