SMITH MACHINES as compared to FREE WEIGHTS
There's one fact in the smith machines that nobody can deny, they are safest way to workout even though they may not be the best. The smith machines are also very easy to use too-just insert the pin wherever you want to and your ready to go...
You never need to have to ask for a spotter and neither do you need anyone to put the weights back on the rack. You wont get stuck with the weight behind your back or on your chest on the last rep, the machine takes care of that! The above reason of safety was exactly why the smith machines were created and also many bodybuilders found these a 'cool and hi tech equipment to workout with' so they grew in popularity very soon , add to that a belief among people that you'll become more stronger if you us the machine. This is the point where the real demerit of the machine comes.
As I said earlier many people whenever they workout on the smith machine feel they are becoming stronger as compared to when they were using free weights. This is totally untrue , the simple fact is that free weights provide a full range of motion - positive and negative motion while the machines only provide you the positive motion. For Truly isolating the muscle the negative motion is as important (in some cases even more) as the positive one . Your muscles tire out because of this in about half the time as compared to machines if you use the same weight on both. So a guy who can bench press only 225 lbs using free weights can do more than 275 on the machine! But still his muscles don't get the complete workout as provided by free weights.
These machines soon become frustrating to most users which is why any dedicated bodybuilder uses mostly free weights, using the machines only occasionally, or as an warm up exercise.
WHICH EXERCISE ON WHICH EQUIPMENT
In my opinion the exercises which can be done on the machine and still give a good workout are still varied and many. The most obvious of these exercises are the Leg Press, Leg Extensions, Flyes and half squats. The machines are able to provide the full range of motion in these exercises and they are easier to operate too so these exercises can be done on machines.
On the other hand Exercises like Flat Bench press and its variations, full squats, Preacher curls, Deadlifts and Shoulder press give best results only when done with free weights .You can never expect machines to take over as the king at least when it comes to these exercises.
WHY FREE WEIGHTS ARE STILL THE BEST
One more reason to use free weights is High Intensity. It's very difficult to have an intense workout on a machine . It's only when you do a very intense set using heavy weight and many muscle groups (squats, dead lifts, bench press) that you body releases growth hormone and adrenaline, which give you growth and energy respectively. You will also burn up glycogen which is important after a good set. With machines, it's impossible to generate this level of intensity. The way it makes you to move just doesn't allow it, and having the weight get , heavier the harder a guy tends to press, it is never enough. Glycogen isn't used up well either if you do all your primary exercises on machines.
I have already said that machines do have their importance for beginners (to develop a base), recovering from an injury, as a secondary workout equipment and to make sure certain muscles get back to work. If you have a pulled or injured muscle group a machine may be safer than free weights until it recovers . Anyone who starts training on machine and then switches to free weights will have great results to show off!
So to all the guys who have been training for a while, its now up to you for what you want - a fake sense of power and incomplete training or Real Power and Real intensity ? This decision is entirely yours.