But which ones will work best for you, and how do you choose? Here’s what a few personal trainers have to say about the benefits of using YouTube when you want to build strength, burn calories, get lean, and have fun in 30 minutes.

You Don’t Have to Hustle to Make It to the Gym

“I think the accessibility of [home workouts] is why they’re popular,” says Jessica Cifelli, a certified personal trainer with the National Academy of Sports Medicine who’s based in Wyckoff, New Jersey. “While so many people enjoy group classes, they don’t always fit into people’s schedules.” Having the ability to work out whenever you’re able to fit into your schedule can help exercisers stay committed, she adds. “Time is one of our limiting factors when it comes to exercise … especially for young mothers, working parents, and even college students,” says Pete McCall, an ACE-certified health coach and exercise physiologist for the American Council on Exercise (ACE) who lives in San Diego. “The number two reason why people use these programs would probably be from a financial standpoint,” he adds. “Some fitness programs have subscriptions, some are pay as you go, so you don’t have to lock yourself into a facility, or contracts, and you can opt out at any time.” RELATED: 9 Tricks to Help You Start Working Out and Actually Stick to It

But Is the Trainer Who’s Inspiring You Legit?

Make sure that the person you’re getting exercise advice from has certifications from an accredited organization, says Cifelli. “I would definitely recommend you look for somebody who is certified by the American Council on Exercise,” says McCall, the spokesperson for that organization. “Whether they’re a group fitness instructor or personal trainer, having the ACE certification ensures that that instructor knows how to design a safe and effective exercise program for healthy adults. My fear about a lot of these videos on YouTube or Instagram is that just because someone looks like they’re fit doesn’t mean they actually know how to design a safe program.” Other respected organizations include:

the American College of Sports Medicine (ACSM)the International Sports Sciences Association (ISSA)the National Academy of Sports Medicine (NASM)the National Strength and Conditioning Association (NSCA)

If you’re feeling like it’s time to ditch the gym, here’s information about eight YouTube fitness stars who want to help you get fit fast — and for free: RELATED: 6 Low-Cost Workouts to Help You Control Diabetes

Jessica Smith TV

Fitness trainer Jessica Smith has more than 15 years of experience training clients on both coasts, and holds certifications from the American College of Sports Medicine and the National Academy of Sports Medicine, among other institutions. McCall, who used to work with Smith, says she does a great job of putting out safe and effective workout videos. There’s something here for everyone: Smith has 30-minute kickboxing workouts, ballet body sculpts, abs cardio, and HIIT (high-intensity interval training) for beginners sessions. Bonus: Many of her videos guest star her adorable French bulldog, Peanut, who usually sleeps on Smith’s mat during the workout, looking up with an expression on her face that says “Are you done yet?”

Blogilates

ACE-certified fitness instructor Cassey Ho has more than 4 million subscribers to her YouTube channel, which features workouts like POP Pilates and PIIT28 (Pilates intense interval training). Ho’s known for her cheery, upbeat personality, fun music, and the fact that you can do many of her workouts anywhere. There are a ton of challenges to choose from on her YouTube page, and she’s ultraspecific in her focus. She’ll target particular body parts and give you a goal — getting a perky butt, thigh trim-downs — and most of her workouts are under 15 minutes. (Some are even 10 minutes.) She even has “quiet cardio routines” you can do in your apartment without fear of bothering your downstairs neighbors. RELATED: Essential Yoga Props for Improving Rheumatoid Arthritis Symptoms

BodyFit by Amy

NASM-certified personal trainer and fitness instructor Amy Kiser Schempe took the workouts she’s shared with her clients for 15 years to create her BodyFit By Amy fitness channel on YouTube. Her videos cover TRX, kettlebells, no-equipment workouts, dumbbells, wedding workouts, postnatal workouts, full-body workouts, and other options that can give you a 30-minute routine to get your heart rate up.

Barre3

Want to try those ballet-inspired barre exercises at home before shelling out money at a boutique studio? Check out Barre3 Studio’s YouTube workouts, where founder Sadie Lincoln and her Barre3 instructors show you studio routines you can do at home with no or minimal fitness equipment. You can try a few whole-body workouts that will teach you basic barre moves, as well as advanced exercises for when you really want to feel the burn. There’s also a 15-day free trial program that you can cancel anytime.

Jessica Valant

Jessica Valant’s YouTube channel is packed with short bursts of Pilates workouts that can be done anywhere. Valant, who’s a physical therapist and a certified Pilates instructor, is also a mother who created these videos with the chronically short-of-time in mind. (On her YouTube site she says that the short workouts she found herself doing once she had children were much more effective than the hour-long elliptical sessions she used to luxuriate in before giving birth.) There are 5-minute, 10-minute, and 20-minute workouts on the site, targeting different areas of the body, given with modifications to make the exercises gentler for those who need it.

Yoga With Adriene

Kick-start your daily yoga practice by taking on one of yoga teacher Adriene Mishler’s 30-day challenges. Not only does Mishler have yoga videos that are longer than 30 minutes on her YouTube channel, she also offers “yoga for busy people” sessions that take only 5 to 15 minutes. Whether you want to work up a sweat, or calm and relieve a tired mind and body, there are videos here for you.

Athlean-X

Physical therapist and strength coach Jeff Cavaliere, who’s certified by NSCA, created this YouTube channel, where he demonstrates the workouts he creates for professional athlete and celebrity clients. Some of the 30-minute sessions include chest and abs workouts, full back workouts, and nutrition advice. There’s also a related channel called Athlean-XX for Women, led by female trainer Amy Jo Palmquest, who walks women through booty workouts and post-baby exercises. RELATED: What Counts as Aerobic Exercise? Here’s Everything You Need to Know About How to Get the Cardio You Need

HASFit

HASFit stands for Heart and Soul Fitness, founded by ISSA-certified trainer Joshua Kozak — who, in a former life, was a professional MMA fighter. But his videos are full of Midwestern sincerity and nonsappy encouragement. He and his wife Claudia perform the workouts on their YouTube channel, which, they say, “will always be free because we believe that every heart and soul deserves to be fit.” The channel, which has had more than 130 million views, features hundreds of free 30-minute workouts, designed for everyone from seniors to first-timers to “Warriors."