How many times a week can you have arm day? We asked a trainer to find out

The other day, I was lifting weights to work my arms when I stopped to wonder: How many days a week should I be isolating them as I lift? We’ve all seen those #armday memes on Instagram, but how many times a week is too many times to work out a single part of the body?

“If you have limited time, that’s when you should do body-part specific moves because you want to focus on what you want to get stronger,” says Lacey Stone, celebrity trainer and founder of Lacey Stone Fitness, which offers virtual fitness training.

Here’s the deal, though—different body parts get their own days because, well, training is hard. “Strength training damages your muscle fibers and causes them to break down,” says Andrea Somer, Equinox tier 3 personal trainer at Equinox Santa Monica. “During recovery, these muscles can repair themselves and grow stronger than before.” Hence why after a hard workout day, you’re sore and/or limping around like you’ve just gotten beaten up (just me?).

It’s because of that soreness that people train different body parts on different days. “If you break down your workout days by body parts, you can allow those muscles to recover for 48 hours while still being active and training a different muscle group the next day,” Somer explains. At the same time, of course, everyone’s recovery time and lifestyles are different. “If you have great recovery abilities because you eat well, supplement your diet, get plenty of rest, and are under less stress, you’ll be able to train harder and more often,” she says. “Also, depending on your intensity and volume during your workouts, the higher they are, the longer recovery you might need—always listen to your body.”

Now down to the real logistics: Typically, you should alternate the days you work out different limbs. “If your goal is to tone your legs, do them 3 to 4 days max, and if arms are secondary, do them 1 to 2 days,” recommends Stone. Obviously, this is just a guideline, so you can always adjust based on how many days per week you’re working out. “Just don’t train the same muscle group two days in a row if you’re working out 5 to 6 days a week,” says Somer. “Legs and back have more explosive fast-twitch fibers and have more room for growth as well as increased soreness.” And so with this knowledge you can now pick and form your very own workout schedule.

If you’re in need of inspo, here’s a 10-minute resistance bands arm workout. And this is a 15-minute at-home ab workout you can copy from Akin Akman.