Hi Folks and may I take this opportunity to welcome you into 2021 after what I hope was a lovely Christmas and New Year celebration. I imagine many of you (myself included) have enjoyed the Christmas festivities and overindulged on lots of lovely food and drink. So what better time to have a small chat about our weight. This, the first of a two part article will deal with a little bit of science and next month’s article will put some meat on the bones (pun not intended).

Hi Folks and may I take this opportunity to welcome you into 2021 after what I hope was a lovely Christmas and New Year celebration.

I imagine many of you (myself included) have enjoyed the Christmas festivities and overindulged on lots of lovely food and drink. So what better time to have a small chat about our weight. This, the first of a two part article will deal with a little bit of science and next month’s article will put some meat on the bones (pun not intended).

Did you know that if you deconstructed an 80kg human into it’s 20 elements you would get approximately 52kg of Oxygen, 14.4kg of Carbon, 8kg of Hydrogen and 2.4kg of Nitrogen. These four main elements account for over 99% of your weight. They are found throughout your body, mostly as water but also as components of biomolecules such as fats, proteins, DNA and carbohydrates.

Lets take a closer look at the body’s two main forms of energy storage, fat and glycogen:

FAT

For every gram of stored fat you get 9 calories of energy, therefore one kilogram of fat provides 9,000 calories of energy.

So if that same 80kg human had a 12% body fat reading (very low and fit) they would have 86,400 calories of fat and be able, in theory to fuel themselves for 36 marathons on stored body fat alone!

However the guidelines on acceptable body fat readings have the upper limit for a 40 year old man as 27%. That’s 194,400 calories or 81 marathons (nearly 2 ½ times Lands End to John O-Groats by road)!!

GLYCOGEN

Stored glycogen is the multi-chain (polysaccharide) form of glucose sugar that the body stores primarily for short term bursts of energy such as sprinting, power and strength movements.

So our 80kg human will store approximately 480g of glycogen throughout their skeletal muscle and about 120g in the liver. For every gram of stored glycogen you get 4 calories of energy. So with a total of 600g of stored glycogen available he/she is provided with 2,400 calories, enough to complete one marathon without refuelling.

In reality you wouldn’t want to try either of these extreme fuelling methods alone and in fact the body burns both fat and glycogen simultaneously but in different ratios depending on the intensity of exercise. We shall look at this in more detail next month.

Andy