If i stop exercising for a few days, how long is the delay before i'll probably start to gain weight?

Weight gain: There are 3500 calories in a pound. Say you usually do 500 calories of exercise a day,,, you'll gain a pound a week. if you are sedentary more or less,

Depends: Depends on how much you exercised in the first place and calorie intake. Why stop?

Diet and exercise: Losing weight is a result of both diet and exercise.70% of weight loss is controlled by nutrition therefore if your nutrition is optimised when you give up exercise, you can still manage to control your weight. It is all dependent on how much exercise you were doing and what your diet is like. See a dietician for more advise resgarding weight loss

Nutrition: You may find you can simply maintain the weight loss with diet alone. It varies how quickly people will regain weight if they stop lifestyle changes, body composition etc. It depends on the energy balance - what goes in, what goes out and how quickly you burn energy (basal metabolic rate). You could see a dietician if you wished to calculate this more professionally and precisely

Weight : It's hard to answer that as weight gain depends on what's is the person's daily calories intake and how much energy is consumed by the body and what is person's metabolic rate . Average Sedentary male needs around 2800-3000 calories . For weight gain we will need to increase calorie intake and stop exercising. If there are no physical reasons then results should be evident in few days to weeks .