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Energy systems – how the body acquires the fuel it needs for energy production

How is everyone this morning? What are you thinking? Are you focused on today’s plan and activity? What are you getting up to that will benefit your long term health today? Have you smashed some decent exercise this week? Have you perhaps beaten your personal best on one of the cardio machines and feeling pretty dam good about that? Or lifted an extra weight or for more repetitions this week? Perhaps you ran to the second lamp post instead of the first or maybe you’ve entered your first ½ marathon for 2018?

If you’ve created some momentum this week then keep that ball rolling! If things possibly didn’t go as well as you hoped then guess what...there’s still plenty of time to get up and get moving this weekend. There’s still a chance to concentrate on eating a bit better and drinking a bit more water know you can always do a bit better team. Today’s Topic: Energy systems – how the body acquires the fuel it needs for energy production.

What food groups are essential in your diet and how are they used?

Energy is required for every bodily function

This energy comes from food, the air and the sun.

Each one of these energy sources is metabolised differently to generate useable energy.

Food provides fat, carbohydrate and protein, plus vitamins and minerals that are required to assist in chemical reactions needed for healthy bodily functions.

And the only energy unit useable by our bodies is adenosine triphosphate (ATP).

Once this ATP is generated it is used in one of the three energy systems to fuel activity.

What are the three energy systems?  Aerobic system  Lactic Acid system  Phosphocreatine system

The Main Food groups that influence the energy available to fuel activity

Carbohydrate  Due to its molecular structure it the simplest of the different food groups to convert into useable energy.  It’s the preferred source of energy to make ATP  Available in 2 forms: simple sugars (sugar & sweets) or complex sugars (cereals, rice & vegetables)  Both simple and complex provide the same amount of energy but the complex takes longer to digest because they contain fibre  Not easily stored in the body – small amounts (approx 2000 kcal) are stored in the muscles & liver in the form of glycogen  Carbohydrate (glycogen) stored in the muscles can only be used in the muscles  Liver glycogen can be broken down & released into the blood stream as glucose (sugar)  Important to refuel with carbs regularly especially during & after activity.  Carbs in blood stream will be used immediately for energy or stored for later use.  When carb supplies run short the body shuts down “non-essential” functions & sends the small amount left to the brain.

Fat  Fat provides the greatest amount of energy  Fat is stored in the body – underneath the skin and around the organs  Hormones stimulate the breakdown of fat in the adipose tissue into fatty acids to be used for energy production – this process is called Lipolysis.  As your fitness improves your ability to extract energy from fat improves.  Fat needs a lot of oxygen to be metabolised effectively.  The cardiovascular adaptations that occur with regular cardio workouts improve the ability of the body to take up oxygen & deliver it to working muscles – this makes it easier for the body to use fat as fuel at high intensities (HHIT).  Fat is a useful survival mechanism – carbs run out quickly but there is an abundant supply of fat to fuel ongoing activity.  A fit person can spare the carbohydrate until it’s really needed and maintain activity using fat as the main fuel.  You need carbohydrate to aid the metabolism of fat Protein  Protein is stored in the body as muscle  Only used for energy production when carbohydrates stores are depleted.  Proteins need to be broken down into amino acids and converted into glucose by the liver if they are needed for energy production (gluconeogenesis)

Fuels for energy systems • Muscle glycogen is stored to fuel muscular activity • Liver glycogen is intended for use by the brain • If there is no glucose remaining in the blood and the liver glycogen is running low then you must eat carbs or the body will start to make carbohydrate internally (gluconeogenesis). Amino acids are used for this through the breakdown of your muscles.

What happens when I exercise? • The demand for ATP synthesis depends on the intensity of your exercise. • The higher your intensity the more ATP is required & the quicker it needs to be synthesised. • If it can’t be synthesised quickly enough (usually takes more than 10 seconds) then we have to lower the intensity of the exercise • Ideally the body will use a mixture of fat (in the form of fatty acids) and carbs (in the form of glucose) to make ATP. • Fat can only be metabolised in the presence of carbs • Fat can only be used in the presence of oxygen • If no oxygen then only carbs are used • We have plenty of fat stored but it takes a relatively long time to metabolise. • Carbs are metabolised much quicker but we have low stores of it. Fitness Fact of the week Sleeping 6 hours or less per night can increase your IL-6 which is marker of systemic inflammation – this is associated with insulin resistance, cardiovascular disease and osteoporosis. Quote of the week “There is a vast difference in being busy to being focused” Keep active & see you soon Rosie

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