The gym floor usually segregates free weights and resistance exercise machines, and sometimes people aren’t sure which to use and why. In the most general sense, machines are used to target very specific muscle groups, whereas free weights engage surrounding muscle and work on balance as well.
Free weights are an excellent way to work on both strength and endurance by varying repetitions and load. They are so effective because they almost perfectly simulate ‘real life’ exercise, such as lifting logs, pulling carts and plowing fields – which is what our bodies have evolved to respond to. They also work on muscle balance and improve the way ligaments and joints function in unison. This is because a dumbbell chest press, for example, engages more than just the chest muscles during the motion. First of all you need to get the weights into position and then use your shoulders and arms to press the weights into position – all the while balancing and readjusting – which engages surrounding support muscle tissue.
Machines serve their own purpose in the gym and shouldn’t be neglected, despite the advantages of free weights, as outlined above. They are very effective at isolating muscle groups and so are often used during recovery after injury and physiotherapy. However, this advantage is also their weak point, as becoming good at a machine will only make you good at that particular machine – it won’t increase your ability at anything else.
Cable workouts are very effective at toning and should be used in conjunction with free weights. They are generally used for high repetition workouts as this is the best way of achieving definition. They should not be used for strength building or mass gain, as you generally can’t lift as much as with free weights.
The great thing about workouts involving free weights, cables and machines is that you continue burning calories even after leaving the gym. This is because of the interval training style of switching between high intensity exercise and rest over an extended period of time. This form of workout increases metabolic rate and so you will continue burning calories for several hours after lifting weights as the body recovers. This is in contrast to endurance (flat heart rate) cardio, in which you only burn calories during the actual activity.