Risk is inherent in every activity we do, all day long. Anything can kill or injure you, its just a matter of odds. You might think that sitting on your sofa all day long is safer than those "dangerous exercises" at the gym, but think again. Obesity related diseases are the number one killer in the developed world and sitting on the sofa increases the chances that you will die of obesity related causes. Not only that, people who stay on the sofa without exercising are likely to have weak, atrophied muscles which make them more prone to injury doing every day activities like carrying heavy groceries into the house. So given that everything in life is risky, how much risk is acceptable to you in your exercise program? Here are some guidelines:
"Max gains are worth the risk":
If you are young and in good health and are *really* serious about getting stronger and bigger then you will be willing to do things like squats and deadlifts. It is true that many people who dont have back problems can do these exercises safely if they have been properly instructed but they are still some of the riskiest exercises you can do in the gym. If you want to include squats, deadlifts, and plyometric exercises (also risky) in your workouts then you need to be willing to accept the highest risk level - "Max gains are worth the risk".
"75% of the gains with little risk":
Machines found in gyms are safer than free weights because they safely limit the range of motion and they have safety stops to prevent crushing or falling injuries. A great example is the leg press machine. Whereas all kinds of things can go wrong when you are squatting with a heavy bar on your shoulders, there is precious little that can go wrong to hurt you on a leg press machine. Is it as good as squatting? No, but its probably 75% as good as squatting and its a lot safer. For people who have bad backs sensitive to compressive loading, leg press machines are a godsend because no compressive load is placed on the spine. If you want most of the gains with very little risk of injury then select the option - "75% of the gains with little risk".
Avoiding injury is the primary goal:
For the elderly, very young, frail, and the injured, the primary goal should be to avoid injury. Even though machines in gyms seem to have been designed by lawyers trying to avoid lawsuits, some of the machines in the gym are still to risky if you are in this category. Selectorized machines are typically safe by many free weight exercises are simply out. An exercise like a bent over row would be out of the question because of the potential for a lower back injury. If avoiding injury is your primary goal, you will still be able to get stronger doing some simple, safe exercises but you will not put on any appreciable muscle mass. If avoiding injury is your primary goal, then select the option - "Avoiding injury is the primary goal"
How strong do you want to be and are you willing to take the risks?
How muscular do you want to be and are you willing to take the risks?
Before starting *any* workout program, you need to discuss it with your doctor to make sure it will help you rather than harm you. Only your doctor is in a position to make that decision based upon your medical history, friends, family and personal trainers are not in a position to make this decision.