To build muscle mass, you should try to work each muscle group two to three times a week, Tamir says. If you’re following a two to three-day strength plan, this means you should aim to do full-body workouts, giving yourself 48 hours in between each session to give your muscles time to recover.

The major muscle groups of your upper body and lower body include your chest, shoulders, back, arms, glutes, quads, and hamstrings. And don’t forget to include some core exercises, too. That might sound like a lot, but this is where compound exercises can be executed. Moves like squats, lunges, rows, and chest presses work more than one muscle group at a time, so you get more bang for your buck.

You also want to have a balance between pushing movements (like an overhead press or bench press) and pulling movements (like a bent-over row or pull-up). Remember, strength training is not just about free weights or machines—mastering bodyweight moves will challenge your muscles too.

Shoot for 12 to 15 reps per set when you are just getting started, Fagan says. Once you’ve become more comfortable with the moves, you can add more weight and decrease the reps. One to two sets of each exercise is enough for your first month, after which you may want to increase it to three, she says.

Each of the three strength sessions should have different moves, but repeat those same exercises every week.

“I would stay with a program for four to six weeks and progressively increase the weight,” Tamir says. The week before your last week, he suggests lowering the weight a bit “to give your body a little bit of a recovery, and the last week really push it hard.”

How to incorporate cardio in your routine

As important as it is to strength train, cardio also has its place in a balanced workout routine. “Doing cardio keeps your circulatory system working optimally, helping you to recover faster, [and it] keeps your endurance up,” Tamir says. “It also increases your VO2 max, which helps your body utilize oxygen.”