From the standpoint of basic exercise physics weights and resistance bands have a lot in common. Both provide something for the muscle to work against beyond gravity. But the detailed differences allow them both to serve different goals.
A weight, whether in the form of a free weight or a stack on a machine gives you the opportunity to exert a varying degree of force. That makes it possible to tailor your workout to your level.
Weight training improves strength over time, while tuning the cardiovascular system which reacts naturally to supply muscles with what they need. As you build strength you are improving coordination, creating a stable body environment for joints and making the heart work, which improves overall health.
Resistance bands offer similar benefits, along with some of their own.
As you increase the amount of stretch, the band pulls back with greater and greater force. To get a feel for the amount of that force consider a highly stretched rubber band. It travels a lot farther when released than a limp one.
Resistance bands help increase bone density, as the body reacts to the strain by releasing biochemicals that add calcium. It's very indirect, but the effect is real, even while it's gradual. That effort increases the metabolic rate as the body supplies oxygen to tissues.
Beyond the valuable workout benefits there are convenience benefits to exercise bands, too. They're ultra-easy to store, since they'll fit into a drawer or on a closet shelf with no problem. Lightweight and ultra flexible they are even easier to handle than small dumbbells. And a lot safer.
In both cases - band or weight - the muscles have to work against forces directed against them. But now look at the differences in how those two types of force are applied. They tend to operate in different directions.
The difference in those two directions creates an opportunity to work different muscles in different ways. Both help enhance strength, but using both gives you a much wider variety. That leads, in turn, to a workout that is more comprehensive.
For those who are recovering from an injury, whether from a previous workout or more long term, an exercise band can be a little easier to use in some circumstances. You can insert a foot into the handle of a resistance band, then take up the other end with your hand. Or, you can use both feet to stretch the band. That gives a range of exercises it would be hard to duplicate with weights, unless you invest in some expensive equipment.
Free weights on the other hand, say in the form of small dumbbells, can offer a great way to do some curls even in a wheelchair. It's possible to use a resistance band that way, but it can be more difficult, depending on the type of injury you have.
Both methods have their strengths and weaknesses and the ideal workout program will incorporate both to get the best of both worlds.
Dumbbells or free weights offer a number of advantages over weight machines. But the latter are not without benefits, either. In the end, the decision of which to choose or use will come down to cost, space and the type of workout you're after.
Dumbbells typically come in the form of a short bar with a weight on each end. Some are one-piece molded plastic (usuallly neoprene). Others have discs that can be swapped out, added to and so forth. The integrated style have the advantage of being low-cost, very sturdy and relatively safe to use. But you'll often want several pair of different weights, offsetting the savings. Adjustable free weights allow you to choose how much weight you want to work with, but require a little time and sometimes a tool to make the swap.
Both offer an excellent range of motion that can be approached by very few weight machines. They allow you to move the mass any way you want so you can tailor your workout. It's difficult to find a machine that will allow you to do curls, wrist work, deltoid development and more. When you can, it requires having more than one station on a weight machine, which increases its cost.
But, dumbbells can be a little riskier to use. While caution is required with weight machines, too, they make it less likely to slip and hit yourself with the weight. A weight machine offers a stack that slides up or down a fixed pole or an in-built resistance mechanism and it's practically impossible to topple them over.
If you curl a free weight fast and hit yourself in the chest, you won't be the first one to get a bruise that way. Many a foot has experienced the force of a dropped dumbbell, too. Getting ones made of neoprene helps only slightly, since 20 lbs dropped on your toe hurts whether it's made of metal or not and the material is not spongy.
Free weights, since they're quite a bit smaller than even the smallest weight machine, provide the ultimate in space savings. A weight machine will take up about as much space in a room as a treadmill, sometimes more if it has multiple stations. Dumbbells can easily fit under the bed or in the closet.
They're also very flexible. Many models allow the weights to be attached to a barbell, which increases the value of your investment. Just remove them and slide them onto a bar that may be up to several feet wide and you can have an entirely different kind of workout.
Weight machines offer a different kind of flexibility, though, one that can particularly benefit the novice. With a weight machine it's very easy to design a workout that is tailored to very specific muscle groups. Free weights make it a little more difficult to control the movement to hone in on just the ones you want.
If you're on a strict budget, it's best to start with a small set of dumbbells. Non-interchangeable plastic models sell for only a few dollars, but even a set that can be loaded up to 50 lbs or more can be had for a few hundred. A discount weight machine will start at that price and go up from there.
Also, if you want the most flexible workout possible, free weights are the way to go. Weight machines have some terrific benefits but dumbbells provide the greatest possible range of motion for the most varied workouts.
