hey another random one but this one applies to me.
At the gym I got to (its the only one available) they only have dumbells, a smith machine, some light bars and few free weights to go on the free bars. (there is plenty of weight for the smith machine.) they also have a lot of machines upstairs but I stay away from them.
Now for bench press I have 2 options either dumbell bench or smith bench. What would you choose?
Smith machines are good if your training without a spotter since you can rack them easier than a barbell if you get into trouble. Also because the smith machine is on runners you dont have to worry about balancing or stabilising the weight compared to using barbells and dumbbells so you should be able to lift a heavier load. But for a fighter you want to be using equipment that is consently moving and challenging your muscles in different ways, the same way your body will be challenged in a fight by a moving opponent.
On a smith machine you can place your feet further forward and lean back into the bar. This way your back will be straighter while performing the squats and so there is less stress on your lower back. Positioning your feet so your knees dont travel over the toes during the movement will help to keep the stress off your knees so I would not say they are bad for you as long as your technique is strict. I would still say do the free bar squat instead if you can since this will work more of the core muscles and give you more overall benifits. Make sure you get someone to show you the correct technique if you have not done it before since its an exercise that people often do wrong and this can lead to lower back and knee problems. Hope this helps.