So I'm overweight and I'm trying to lose weight. My question is: does the over fat turn into muscles with training? Because I was wondering if doing cardio and some lifting will just get me lose weight only and not build muscles. I.e. I thought maybe after losing the overweight, then I should completely left to only lifting with a specified diet in order to get some muscles. I don't want big muscles, but just nice looking body for the beach. So is my over fat going to be muscles with the training or what?
No, fat does not directly turn into muscle. The body breaks down your fat, as well as your food, into usable energy to fuel your daily activities and your exercise. If you eat too much food, your body does not bother to break down the fat. It just uses the food you have eaten.
If however you do more activity or exercise than your food (calories) can supply, then the body will break down your fat stores into usable energy. That is why to lose fat you need to address your diet and increase your activity or exercise.
If your exercise loads your muscles causing them to become stronger, then your muscle will develop more. You increase your muscles when you load them or stress them thru exercise or work. They respond to the stress by getting stronger in preparation to meet the need for the next time you work them.
Both cardio and lifting weights will burn calories. When your body is ready to handle more intense exercise, you can increase the intensity and achieve more "calorie burn" even after you have finished exercise.