What is a Calorie?

With the continued talk of ‘How many calories are in that sandwich’ to ‘How many calories can I eat in a day’, it is important to understand… What a calorie actually is? Without getting too technological on you: Calories are a measure of the amount of energy in food. We all need energy to function, much like a car needing petrol to drive. Energy from calories fuel your every move – from fidgeting to running.

When looking at weight loss or even weight gain, it is the balance of calories in versus calories out. In order to maintain our weight we must use the same amount of energy that we put in. It is when we consume more calories than we burn that we start to gain weight and over time this excess energy is stored as body fat.

The NHS Guidelines for an average daily calorie intake are: a man needs around 2,500 and a woman, it’s  around 2,000. Amongst other factors, these values can vary depending on age and levels of physical activity.

In order to lose weight you need to burn more calories than you eat. A safe amount of weight to lose in a week is approximately 1-2 pounds. This is a realistic target and is something that is more gradual, therefore more likely to stay off.

One pound of body fat is equal to approximately 3500 calories. In order to lose weight (1 pound a week) you could decrease your calories by 500 per day (500 x 7 days per week = 3500 calories).

Calorie counting can be daunting to start with but there are some good apps out there that can help make it a lot easier. I use My Fitness Pal on the iPhone, which allows you to manually enter or scan the barcode of food and drink products, displaying the calorie content for you.

The amount of calories we use throughout a particular activity or fitness class are dependent upon a variety of factors including; your weight,  gender and intensity level.  Throughout all of my classes this week I have been strapped up, monitoring my heart rate level in order to see how many calories I am burning. Results are as follows:Watch Calorie Display

Body Blitz (60 minutes) 441 Calories

Body Blitz (40 minutes) 227 Calories

Boot Camp (45 minutes) 263 Calories

Conditioning (45 minutes) 236 Calories

Zumba (60 minutes) 433 Calories 

Please remember these are based on me – therefore at my weight and intensity level. The heavier you are the more calories you will burn due to the extra energy it takes to perform the activity.

Remember – calories are burnt all day long, not just when you are exercising, they’re even burned in your sleep

Are you surprised by the amount of calories burnt in each class? Did you think it would be more or less? Please comment below and I look forward to hearing your thoughts…

Lorna Catchpole


  1. Grace   Ã¢Â€Â¢  

    It feels like I burn 4,000 calories at Zumba!!!

  2. Dawn   Ã¢Â€Â¢  

    Love these blogs there so informative .thanks lorna x

  3. Carly   Ã¢Â€Â¢  

    It’s interesting the difference between 45 mins and 60 mins of the same class. Obviously once you’ve got your heart rate at that calorie burning level those extra 15 mins really do count!

  4. Sue   Ã¢Â€Â¢  

    Really, I thought it would be more, it certainly feels like more, oh well must try harder

  5. Denise   Ã¢Â€Â¢  

    omg – that pie was kj 3159 – how many body blitz’s to burn that off – hubby is off the cooking agenda

  6. Kim   Ã¢Â€Â¢  

    Found the information about losing just one pound very interesting. Seems very daunting to reduce calorie intake by 500 calories per day though

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