How Many Calories Do I Need to Burn In An Exercise Session?

People exercise for different reasons. Some do it to maintain themselves as part of a healthy lifestyle, and others do it to build muscle. But for many of those taking up exercise for the first time or returning to it after a break, their primary goal may be fat loss.

There are a breadth of fad diets and complex fat-bu ing fitness regimes available today. But when you strip the weight loss process down to its barest definitions, it is a fairly straightforward concept:

To lose weight, a person needs to create a calorie deficit.

In simple terms, this means expending a higher number of calories through physical activity than the number consumed through food.

How do calories translate into weight loss?

It is generally accepted that for someone to burn off 1lb of fat, they will need to create a deficit of 3,500 kcal.

So for instance, if someone ate 1,000 kcal but burned 1,500 kcal every day for one week, this daily deficit of 500 would add up to a total of 3,500 over the course of seven days, and in theory make them one pound lighter.

What should my weight loss goal be?

It depends mostly on how much you weigh and how much you want to lose.

The heavier someone is, the faster the rate at which they can safely lose weight.

Of course, you should always speak to your doctor before embarking on any programme of weight loss.

However, the widely recommended safe rate, which is useful for someone who is overweight (with a BMI of 26-30) to consider, is between 1 and 2lbs per week.

So in theory, someone who wishes to lose 7lbs may be advised to do so at a rate of around 1lb per week for seven weeks.

For someone in this weight range to lose pounds at a faster rate could be potentially dangerous, as the calorie deficit the person would have to maintain would require them to eat drastically less, which could lead to malnutrition.

Those who fall into the obese range (BMI 30 and above) may find that they are able to lose 3-4lbs per week without causing any significant health issues; as the heavier someone is, the more calories they will naturally burn when performing exercise, as their body has to worker to support a greater weight.

Essentially, this means if you take two people weighing different amounts, eating the same number of calories and performing the same exercise for the same amount of time, it will be the heavier of the two who burns more calories (and in theory creates a larger calorie deficit).

For instance, the MET value system allows us to see that someone weighing 140lbs cycling very fast for 30 minutes would bu 382 kcal, whereas someone weighing 210lbs doing the same thing would bu 573.

That said, even for someone who has a BMI of 30 or above, it’s still advisable to set a goal which follows a gradual and sustainable rate of weight loss.

How many calories should I try to burn through exercise?

Trying to determine a target calorie burn figure per exercise session is possible, but can be complex, as there are a number of factors to take into account.

To start with, the amount of calories you eat and your target rate of weight loss will both have a huge effect. The more weight you’re trying to lose, and the more calories you consume, the higher your calorie burn target will be.

It’s also important to remember that the body burns calories when it isn’t exercising, as maintaining organ function requires energy. Your basal metabolic rate, which you can use this tool to calculate, is the rate at which your body burns calories when it is resting.

The body also burns calories during activities such as walking and performing everyday chores. The 2011 Compendium of Physical Activities provides MET values for a range of these. To work out the hourly calorie burn for a particular activity, all you need to do is multiply this MET value by your weight in kilograms.

Once you’ve worked out how much weight you want to lose, how many calories you consume, and take into account the number your body burns without exercise, then you may be able to get an idea of the number you should be aiming to burn per session, and the type of activity you should be doing.

However, it’s perhaps more useful to set a target which focuses on duration as opposed to calorie burn numbers.

The CDC recommends two and a half hours of moderate intensity exercise per week (examples of this might be swimming or walking) or 75 minutes of intense exercise per week (such as running, cycling or sports).

This is a good starting level for those looking to embark on a programme of weight loss. The more comfortable someone becomes with this level, the more they can then begin to build on this and incorporate more.

Of course, it’s helpful to be aware of the number of calories a particular exercise burns, so that you switch to an exercise with a higher burn rate if you’re short on time one week, or aren’t seeing the kind of progress you’d hoped for.

In any case, it’s better to work with your doctor when developing a diet and exercise programme, as they’ll be able to help devise one which suits your individual needs.