Energy Needs

menu_book picture_as_pdf book Sonya Muhlsimmer Bushcraft Australia

Issue_34_April_2019-60

Energy NeedsHow to Climb That HillSonya Muhlsimmer

How much energy do you need? Food for two people for a 14 day hike. I hope this enough ...

Do you count in kilojoules, or calories? They are the same thing, but just a different scale. Kilojoules (kJ) are a metric scale and Calories (Cal) are an imperial scale, so technically speaking it is kJ in Australia.

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... and bagged ready for the walk

Kilojoules measure how much energy you intake out of your food or drink. Energy in is the food and drink consumed and energy out is the energy the body has used for basic functions like breathing, thinking, moving around and even sleeping. So remember this: Energy in equals Energy out. By the way, the brain uses up more energy than any other human organ, up to about 20% of the body’s energy needs. Don’t think too hard about this … Have you ever been out on the trail and just had no energy at all, everything is an effort and that small hill feels like Mount Everest? That may be due to the food or kJs you have eaten, or more to the point, not eaten.

Your energy needs are determined by a number of things such as how old and how active you are and also your body composition among other things. So the energy out can change over time and it will be different to anyone else. The Australian Government recommends that the daily energy requirements are around 8700 kJ as a ballpark figure. It is a good starting point. But if you have a very active lifestyle, like all bushwalkers have, you need a lot more than that so it is easy to underestimate the amount of energy you are using and need. Thus not getting the right amount of kJs in our diet to allow us to climb that hill.

It is important to try to find the energy in equals energy out balance for a healthy lifestyle, otherwise your body weight can change and being underweight or overweight can lead to health issues either way. Check out Eat for health to find your ideal energy input.

This is quite technical, this energy thing for the body, but everything you need to know about how to get the right balance is in the labels of food, you just need a food science degree to understand it all, easy, right? Lucky though there is ample information on the web, just ask Dr Google a question and you will get an answer. Look at the Australian Dietary Guidelines, Eat for health or Nutrition Australia, among a plethora of information on the web.

Energy comes in three forms – carbohydrates, protein and fat. Oh, and alcohol can be counted as it is full of kJs, but alcohol is full of empty kJs. They are not a good form of energy as they do not contain minerals or vitamins at all, and alcohol gets converted straight into fatty acids and not into glycogen which is a stored carbohydrate the body can easily use and is the body’s preferred energy source, not like fatty acids. So let’s talk about carbs, fat and protein.

CarbohydratesCarbohydrates provides 16 kJ/g, protein provides 17 kJ/g and fat provides 37 kJ/g, guess how much alcohol provides ... a whopping 27 kJ/g.

Carbohydrates are found in nearly everything – fruit, milk, vegetables and grains are just a few examples and they are the body’s main source of energy, also very important for brain function. Your body breaks down the carbs to make glucose, which can be used straight away, or stored as glycogen for later, when you climb that hill. But the body has limited storage for glycogen so they need to be used up quickly. There are

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simple and complex carbs, simple carbs are in energy drinks, fruit, honey and sugar for a few examples, complex carbs are in legumes, bread, potato and a number of different foods. The difference is how the body uses the energy the carbs provide, and complex carbs are the best for sustained energy. If the energy is not used up straight away, it is stored in the liver or muscles for later. Don’t be a victim of a low carb diet fad, your brain need carbs. The Australian Dietary Guidelines recommend an intake in the diet of 45-65% from carbs.

ProteinProtein is found in fish, meat, egg, legumes nuts and seeds to say a few. Protein is made up of amino acids, the building blocks of life. Human body parts such as hair, skin, nails are also protein based. Once you eat protein-rich foods, the amino acids are released from the food and used to make adrenalin, enzymes, cell to cell communication, new protein like new skin cells, and also help the body to recover after our hike, also they provide some energy. Fad diets such as high

protein, low carb are not great. It is best to stick to a healthy, varied eating plan, and not a fad diet. The Australian Dietary Guidelines recommend an intake in the diet of 15-25% from protein.

FatThere are three types of fat: saturated, monounsaturated and polyunsaturated. They differ in carbon chains. Saturated fats come from meat, dairy, coconut and palm oil and should be consumed in small amounts. Mono and polyunsaturated fats are found in nuts, fish and avocado to say a few and are the better fat to consume. Fats are stored really well in the body as fatty acids, and the energy fat provides is either used immediately or stored and used when needed, or just stored if you don’t use it, if you know what I mean... The Australian Dietary Guidelines recommend an intake in the diet of 20-35% from fat.

Okay, so how much energy do I need again? This is the million dollar question, however this table can help.

Recreation

Kilojoules/30 minutes exercise 60 kilogram female

Kilojoules/30 minutes exercise 70 kilogram male

Mountain climbing

There are no accurate estimates available, but it may require 20-25,000 kJ per day.

Running

1086 A

1200 A

Rock climbing

1380 B

1610 B

Hiking, with light pack

815 A

900 A

Cross country skiing, moderate

1982 A

2364 A

Canoeing

878 B

1025 B

NOTES Average female 40-years-old, 160 cm high; average male 42-years-old, 180 cm high. Figures obtained from (A) www.8700.com.au, and (B) http://nutrition.bizcalcs.com/Calculator.asp?Calc=Calories-Burned-Today).

Check out the calculators and plug in some figures for yourself. This will give you a guideline to see what your energy needs are for that certain adventure you have in mind. Also, once you work out your energy needs, you can work out a menu. Looking at the nutritional panel on the food you want to include in the menu you can do a rough calculation on what your energy inputs are and see if that equals your outputs, thus balancing the equation without even having a food science degree. Or if that is all too

complex and you just want a rough figure, make sure your food kJs for each meal is over 2000 kJ, plus snacks and drinks.

If you plan to do a multi-day hike, or are an athlete this is more important to get it right and work out a menu and do the maths to see if what you want to eat is suitable and ticks the percentage requirements in carbs, fat and protein. The energy in equals energy out in our diet can really make a difference in our health and well being, oh and climbing that hill. Mount Everest anyone?

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