Several studies have shown that there is no difference in development between machines and free weights. One such study compared two groups, one training with free weights and one training with machines. In the end there was no significant difference in the strength increases between the two differing groups.

So now that you know that you can use either option, you need to know how to choose the best one for you.

Consider This...

Will you be training at a gym or at home? This is an important question since this will determine the type of equipment you'll be using. At a gym, you will probably have access to the most sophisticated machines on the market, as well as a full set of free weights. If you are training at home, a set of dumbbells or barbells might be more economical since you could pay thousands of dollars for the latest state-of-the-art machines. It takes very little investment to set up a decent exercise room at home.

How much time do you have to workout? If you have limited time, machines are usually more practical. Most strength coaches agree that workouts are generally more time-efficient when machines are used. The resistance on machines can be set by simply moving a selector pin, rather than by moving plates from a weight tree onto a bar. When you use free weights you often spend more time locating the appropriate weights to use and then finding somewhere to use it. If you are switching between dumbbells and barbells, this can be frustrating when everything isn't right in front of you.

Are you a beginner or an advanced strength trainer? For beginners, machines are a good choice since they are generally easier to use. Most machines have a diagram that shows you how to exactly how to work the machine, and since your body is supported by pads there is a less of a chance that you will injury yourself. If you have never used free weights before, you would struggle to do the exercise is a safe and proper way. If you are an experienced weight lifter then free weights might appeal more to you since you can do a variety of exercises as well as challenge several muscles in your body instead of just one muscle group at a time.

Are you working out alone or with a training partner? If you have a training partner with you, you won't have any trouble finding a spotter for certain free weight exercises such as bench press or military press. But, if you are all by yourself, but still want to lift heavy, head for the machines. You can workout alone without worrying about hurting yourself or getting stuck with a barbell on your chest.

Are you trying to rehab an injury? If you have injury and are trying to get back in the game, machines are usually the best way to introduce you ailing limb, muscle or tendons back to training again.

On last rep. If you are trying to get the most out of each workout in the fastest possible time, free weights is the way to go. It's a great way to incorporate more muscle groups (machines generally target one muscle group) and free weights fit everyone, not always true of machines especially if you are particularly tall or short. The bottom line is that by using a combination of both free weights and machines you will provide yourself with a greater variety of resistance to build a better, and stronger body.