To answer this  we first need to ask another “what is your goal?”, or more specifically, “how much weight do you want to lose and by when?”

Once we have the answer to the second question, we can simply calculate how much exercise is needed based on an understanding of how much energy different exercises burn per minute.

Here’s an example of how we do this assuming that our goal is to lose 10 kilos in 20 weeks, or ½ a kilo per week:

The amount of exercise needed to lose ½ kilo of body fat per week

It has been estimated that ½ kilo (1 pound) of body fat equals around 16,000 kilojoules (or around 4,000 calories). So to lose ½ kilogram of body fat each week through exercise, we need to burn off approximately 2,500 kilojoules (600 calories) extra each day. So based on this figure, the answer to how much exercise is easy: that amount of exercise which burns an extra 2,500 kilojoules (kJ) per day, or 16,000kJ per week. You can use the energy chart provided on this website as a guide, to learn about number of calories burned in 15, 30, 45 and 60 min of various cardio exercises.
As peoples lives are so different, weight loss can’t realistically be reduced to a simple equation like it has been above.

Try exercising for 10 minutes today and add 5 minute increments until you work up to 30.

There are other variables to be considered in the amount of exercise for weight loss equation that weren’t adequately catered for in the above example.

Read the rest here