The fitness world is divided: On one side, you’ve got the purists who swear by barbells, dumbbells, and kettlebells. This crew is all about functional strength—workouts that mimic real-life movements and hit multiple muscle groups. It’s one of the best ways to build overall strength, improve coordination, and develop strength in greater ranges of motion.
But then there’s the flip side: The undeniable popularity of machine workouts that primarily target one muscle at a time—think cable stacks, leg press, or the trusty Smith machine. “Isolation is huge right now, especially with influencers,” says Nate Rodgers, ISSA-certified personal trainer at LifeTime, who are looking not just to grow the glutes but also to bulk up for a desired physique.
The first group of people might be quick to dismiss machines as tools for bodybuilders or people chasing aesthetics, but it’s a bit more complex than that. Surprisingly, studies have found little difference between muscle and strength gain between free weights and machines.
No matter your goal, nearly every piece of workout equipment in the gym (or at home) serves a purpose—except for maybe that rotary torso contraption that has you kneeling while awkwardly twisting your lower half side to side. According to Dr. Rob Butler, biomechanics expert and director of implementation science for Uplift Labs, the key is knowing your goals before you plan your session.
The Full-Body Benefits of Free Weights
Free weights shine for compound, functional movements—deadlifts, squats, lunges, and so on—that recruit multiple muscle groups. They’re also great for building strength through exercises like shoulder presses, bent-over rows, and farmer’s carries. “The biggest difference when we talk about functional movement is there tends to be more bodyweight stabilization with it—it’s more total body,” Butler explains. As you lift a heavy barbell or step into a lunge, your core and upper body are firing, too. Basically, you’re getting more bang for your buck and you can program shorter workouts that hit a wider range of muscle groups.
Free weights also mirror real-life movements. “Functional exercises allow you to create more body awareness and help you improve your mobility, improve your longevity,” says Rodgers. Deadlifts mimic picking up heavy boxes, squats resemble sitting in a chair, and kettlebell swings are like throwing around your giggling toddler. “The general population just wants to be better members of the community, be active, be parents, be brothers, sisters, play in the park,” says Butler.
Plus, for older adults, free weights can actually help counteract age-related decline of motor functions and reduce risk of falls. A 2019 study found that leg strength improved by a staggering 113% over 26 weeks of training compared to a 44% increase from machines. (Studies researching younger adults don’t find significant differences.)
Another surprising benefit? If you want to boost your testosterone, free testosterone (the active form of the hormone) increased more in men that used free weights than machines in a 2020 study in the Journal of Strength and Conditioning Research.
