Weight machines and free weights -- like dumbbells, barbells and kettlebells -- aren't just tools for pumping up your ego or building giant muscles. They're also the keys to developing strong, stable joints; improving bone density; speeding weight loss; and building the strength and endurance it takes to make moving through your everyday life a little easier. Although they offer the same general benefits, you'll find some significant differences between lifting free weights or using a gym machine.
If you intend to work out in the same place all the time, gym weight machines or even a home gym might be a good choice of equipment for you. But if you want a weightlifting workout you can take with you, or want to be able to pair your weightlifting with different apparatus -- like lifting on a stability ball instead of a bench -- opt for highly portable dumbbells and kettlebells. Barbells offer a compromise; you can quickly switch between different benches or stability balls with a barbell, but can't exactly take it with you on a road trip -- at least not very easily.
Get the Best Fit
Most gym machines -- and home gyms -- adjust to fit many different body sizes. But no matter how much they adjust, they can't fit every body. If you occupy any extreme of the body weight and shape spectrum -- very long or short limbs, very overweight or extremely petite -- or if you're just tired of constantly adjusting weight machines to fit you, it might be time to switch to the true one-size-fits-all option: free weights.
Build a Sense of Stability
When you lift with a weight machine, it guides you through a set range of motion. Free weights, on the other hand, force you to stabilize the weights and control every aspect of their motion. This recruits extra muscles to stabilize your joints, which in turn better prepares you to exert the same sort of force during everyday motions. Extra stability of weight machines may be helpful for beginners or those with joint instability.
Don't Drop the Ball
In general, weight machines make it easier to lift heavy weights safely without a spotter; most machines have stops that will keep the handles from coming back and hitting you, even if you drop their weight entirely. With free weights, on the other hand, the only thing keeping you from dropping that dumbbell on your head is -- well, you. That doesn't mean you shouldn't lift heavy with free weights. Do, however, know your limits, practice proper technique and recruit a spotter, if necessary.
How's Your Budget?
If you're shopping for home exercise equipment, dumbbells and kettlebells are almost always the most affordable option, followed by barbells and then home gyms coming in a distant last. If you're working out in a gym, though, you've already paid for access to everything they have -- so go ahead and try both the weight machines and the free weights; you'll quickly discover which feel most comfortable.