Doesn't really matter as long as you are consistent. If you're trying to track your weight it might throw the results off if you mix the two from one time to another.
Exercise isn't relevant to when you weigh in. The best time to weigh yourself is first thing in the morning, before you have eaten anything. Whenever you do weigh in, pick a consistent time of day to get consistent results.
Before exercise and wanting to stay fit you should always eat healthy as possible. For lunch try eat a salad or protein shakes something that is not heavy.
you shouldn't unless you drink a lot of water
depends on how much you weigh
You should walk or stretch before and after exercise, as a warm-up and a cool-down, for the best results.
You shouldn't exercise heavily before using a sauna.
should you do sauna before execise
Everyone should exercise everyday. This weight and height are within the "normal" range. Although the weight is a little low.
One should wait at least one hour after eating to exercise. Allowing your body to digest the food before working out can prevent nausea during intense exercise.
Do A Low-Impact Warm-Up
Gentle exercise in it'self is an excellent way to warm up.
A lot of Factors weigh in here, depending on your age ,fitness family history of heart problems, It would be a good idea to check with you Doctor first before you start any stenous exercise first.,