How many reps, sets should you do? Most people I know say to do 3 sets. I know people who look amazing who swear you only need to do one set of any exercise. I do 3 sets mostly because I feel it will give me more of a weight loss benefit.
How many reps? Convention puts you somewhere between 8 and 15. Start in there somewhere. There are no hard and fast rules, here. There are people who compete in the Olympics whose sets comprise 1 or 2 reps, some whose sets comprise hundreds. 8 to 15 is a good starter range. If you try to do 1 or 2 with massive weight, you're going to hurt yourself. If you do hundreds, you'll get terminal boredom. Also, those two set sizes are for very specific goals you probably don't have.
If you can't do 8, go down in weight. If you can do 15 without any difficulty, go up in weight.
As far as working one muscle at a time, I'll just tell you my approach. I never, ever, at no time do that, ever. In fact, some of the fittest, most cut people I've known did little more than full squats, push ups and sit ups. Obviously, they did variations on these...pistons, fingertip push ups, but think about that. Three exercises, none of which require a trip to the gym, can get you somewhere you want to be.
Nor is it just about efficacy. Each muscle is a part of a larger system of muscles designed to work in concert to achieve motive power. Your muscles are supposed to work together so work them out together. That's my stance.
I'm not saying that isolating is a bad thing, always, no matter what. There are some really good reasons to isolate but, if you don't have one...and I'm going to make the call here, you don't have one...don't do it.
Now, people here and out there might completely disagree with me on everything I've said. This is due to one of the most common aspects of weightlifting...the constant influx of conflicting advice. Think critically and do your own research. That goes for weightlifting and every other thing you do for the rest of your life.
