Machines: The Good

• When it comes to weight lifting, resistance machines are safer and easier than free weights. Machines automatically stabilize the weight, ensuring proper form and safety. It is also easy to isolate a muscle group and work it with a specific machine, making machines a good option for people in rehabilitation after an injury. Changing the weight load is also quick and easy since most machines use a simple pin mechanism along with a weight stack and a system of cables or gears.
  
  

Free Weights: The Good

• Free weights engage all the stabilizing muscles in addition to the core muscle group when you perform an exercise. The need to balance the weight yourself makes each exercise more difficult, and thus more effective. Serious weight lifters choose free weights to increase their overall strength and explosive power. Free weights are also far more versatile than machines. A set of dumbbells can be used to work many different muscle groups. It is also easier to complete a full range of motion that mirrors movements used in real-life or in sports. Athletes prefer free weights because they are able to exercise core muscles as well as stabilizing muscles simultaneously while mimicking movements they use on the playing field.
  
  

Machines: The Bad

• Machines are bulky and expensive. You will have to buy expensive equipment or pay for a gym membership to get access to resistance machines. Machines are much more limited in terms of range of motion. Stabilizer muscles are not worked nearly as hard as with free weights. Overall strength is harder to achieve with machines in the long run.
  
  

Free Weights: The Bad

• Proper form is crucial with free weights, and it is hard to maintain form once fatigue sets in. Incorrect form or too much weight can lead to serious injury. You may need a spotter to assist you when lifting free weights, but you can use machines without assistance.
  
  

Making a Decision

• Beginners should use machines to start out. Experienced weight lifters and serious athletes will benefit more from free weights. Ultimately, a combination of both machines and free weights can be effective for increasing strength and muscle mass.