The Great Gym Debate: Should You Work Out With Free Weights or Machines?

Whether free weights or gym machines are more effective for building muscle is a thought that has probably crossed your mind while you scanned a crowded gym. Curious to know the answer, we consulted Liz Letchford, MS, a BOC-certified athletic trainer and PhD candidate in kinesiology and movement science. She explained that each method has its pros and cons, so before you grab that barbell for deadlifts or hop on the glute machine, let's take a look.

What Are the Benefits of Free Weights?

If your goal is strengthening your functional movement patterns, barbells and dumbbells may be your steel key to success. "Free weights more closely replicate the movements required during more functional tasks like jumping," Liz said, citing a study that found that free weights produce better training outcomes than machines. Further, "barbell squats have been shown to create a greater neuromuscular response than Smith machine squats," she said, and they "generate a greater hormonal response than the leg press machine."

Another point in free weights' favor: they're a better choice for those who are either petite or quite tall. If you're outside the average height range for the machine, it's not going to be as effective. "Machines often operate on a track, forcing a particular range of motion, so if you are smaller or larger in stature than the machine can accommodate, you may be training an inappropriate range of motion," Liz told POPSUGAR.

While there are significant benefits to using free weights, they're not for everyone — particularly beginners who haven't received guidance from a personal trainer or coach. "Free weights are better at challenging your body's ability to stabilize, ultimately requiring more activity from your muscles and leading to greater strength gains," Liz said. "However, if your form is compromised, or you don't have access to a coach who can teach you proper mechanics, machines may be better and safer."

Though free weights can help you improve stability, taking on too much too soon — before you have proper form and stability yourself — can have a negative effect, leading to injury. That said, with the proper supervision of an athletic trainer (ATC) or certified strength and conditioning specialist (CSCS) — or someone similarly credentialed — you could see significant benefits from free weights.

What Are the Benefits of Strength Machines?

As noted, strength machines may be a great option for beginners and anyone who doesn't have a coach or personal trainer. "If you tend to be nervous about your joint stability, starting with machines may feel safer," Liz said. "One approach may be to eventually progress to free weights to challenge your joint stability once you have built foundational strength in the safe environment provided by machines."

Another reason to opt for gym machines? Some of them may be better than free weights when it comes to the mind-body connection. "There are several machines on the market that are actually, pound-for-pound, more challenging to the nervous system than free weights," she said. "Systems that rely on electromagnetic resistance, like Tonal, or pneumatic resistance, like Keiser, remove the self-stabilizing effects of inertia on gravity-dependent objects like dumbbells."

Read: without inertia (remember high school physics class?) to stabilize, your body has to work harder, resulting in a better workout. "When the weight doesn't stabilize itself, your muscles have do much more work, meaning greater neuromuscular activation and ultimately greater increases in strength and stability," Liz explained.

So . . . Should You Choose Weights or Machines?

Liz said if you're just a regular person working out and not a competitive athlete (like many of us), then you can work with both. "If athletic performance isn't the goal, both free weights and machines can improve functional performance, strength, and balance in those who are nonathletes," she said. If you're like us, you like having options, but let's summarize those pointers one more time.

Consider free weights if:

  • You have great form and feel stable
  • You're an athlete
  • You have a personal trainer or coach for supervision
  • You're particularly tall or petite

Consider machines if:

  • You don't have great stability
  • You're a beginner and don't have a coach
  • You're of average height
  • You have a specific at-home machine like Keiser or Tonal