How effective are free weights compared to machines? 2x as much? 3x?
Depends on the machine, application, and desired effects. NOTHING compares to free weight squats or deads in the machine world. For some things like upper back work, machines can be more effective for size gains than most free weight moves. Of all those I have seen the Hammer strenght machines give EXCELLENT results, fit most trainees well, and can provide better results for SOME people than free weights. If you powerlift, well you better be hittin' the slag iron!
One way i think machines (such as smith or hammer strength) are better than free weights is when you dont have a spotter. No going to failure + rest pause reps on bench by yourslef, but you can go all out on the smith machine.
Definitely depends on a number of factors such as what your training goals are(size, sculpting, core strengthe etc), if you have a spotter or not.
I've read that overall machines produce anywhere from 16 to 33% less strength due to the fact that you're not involving as many muscle fibers..particulary stabilizers. That was based on an old study probably from the Nautilus era so those numbers have likely been modified. The newer Hammer machines rock and I wish my gym had them.
I agree with Iron that nothing can compare to free squats and deads and no machine will ever be comparable. Gravity is a bitch but ya gotta lover her anyway.
If you ever start following IA/DC style training... there are some exercises that are just not very practical using freeweights. Try going to failure on overhead dumbbell presses, rest pausing, throwing them back up to strain out a couple more reps, rest pausing, then having to position them AGAIN for the final agonizing reps.
I much prefer free weights to machines....but machines do have their uses as has been pointed out here. like when using ia's routines or when in need of a spotter and no one is avaiable in the gym. I especially like the hammer strength machines, but almost never use the smith...
Free weight anyday of the week. i consider machine beneficial in only a few situations. (when one has an injury, a beginner in resistance training being the main two, with not having a spotter (shouldnt be an excuse though....just get one ) being a semi-excuse in choosing a machine over freeweight lifs. Obviously, exercise such as any calve work really cant be mimicked unless you got a ballzy friend willing to jump on your back and pump out some donkey calve raises