Fueling our Energy Systems

How do we fuel our energy systems?

We've talked about the nutrients we use to produce ATP. Theses nutrients gets converted to ATP based on the type of activity we are performing, the duration and intensity.

Carbohydrates fuel moderate to high intensity exercise, while fats are utilised during endurance events. They are not adequate for high intensity training, such as sprints or intervals.

During low intensity exercise (less than 50% maximum heart rate) there is enough energy stored in the body to fuel it for hours each day, providing we have enough oxygen to allow fat to be metabolised. 

With an increase in intensity carbohydrate metabolism kicks in. This is more efficient, but has limited stores. We can sustain moderate to high intensity exercise for approximately 2 hours with stored carbohydrates (glycogen). Once our carbohydrates stores are depleted and fuel isn't replace we need to stop. Carbohydrates are able to produce approximately 20 times more energy (ATP) per gram when adequate oxygen is available to help it metabolise, than in an anaerobic environment where there is no oxygen, which occurs during high intensity activities.

As exercise intensity increases the efficiency of carbohydrate metabolism decreases and we start to utilise the anaerobic system. This is because the body cannot take in and utilise enough oxygen to metabolise either carbohydrate or fat.

During digestion carbohydrates are converted to glucose, fats to fatty acids and proteins to amino acids. They are absorbed into the blood and transported to:

• Glucose (glycogen) - muscles and liver
• Fatty Acids (Body fat) - adipose tissue
• Amino Acids - the growth and repair of muscles or excreted as waste. These we don't store

Energy Systems

When I first went into my work place, before I even had a job, my now boss said to me;
"If we use dollars and cents as our currency, what's the body's currency"? I had no idea! Well I'm pleased to say I do now!

The Body's Energy Currency is: Adenosine Triphosphate or ATP. ATP is used at the start of all exercise as there is not enough oxygen in the muscles.

Lets look at our Energy Pathways. Where do we get energy from?  We get our energy from food, but before we can use it, it must be broken down. ATP is needed for our cells to function and muscles to contract.

Carbohydrates, fats and protein are all nutrients that contribute to the fuel supply our bodies need to perform exercise.  These get converted to energy in the form of ATP. It is the energy that is released by the breakdown of ATP that allows our muscle cells to contract and our bodies to move. Each of these nutrients are made up of unique properties that will determine how they get converted into ATP.

Carbohydrates are the main source of fuel for moderate to high intensity exercise.
Fats fuel low intensity exercise and for long periods of time
Proteins are not normally used for muscle activity, but rather to maintain and repair the body's tissues.

ATP is not easily stored in our body and what is stored is used up within the first few seconds of starting exercise. As we continue to exercise we need to create more ATP. There are 2 ways the body converts nutrients into energy, they are:

1. Aerobic Metabolism, which requires Oxygen
2. Anaerobic Metabolism, doesn't require Oxygen

Anaerobic Metabolism can be further divided and often uses a combination of energy systems to supply our energy needs. Intensity and duration will determine which systems gets used and when.

ATP-CP
This system supplies about 10 seconds worth of energy during short bursts of exercise (Sprints, weight lifting). It first uses up the stored ATP in the muscle, which lasts for 2-3 seconds, then it requires creatine phosphate (CP) to make more ATP until CP runs out (6-8 seconds). The ATP-CP systems doesn't require oxygen to create ATP. After ATP and CP have been used up the body will move on to another energy pathway, either aerobic or anaerobic metabolism (glycolysis) to create move ATP to fuel exercise.

Limitations of this system:

• Only continue if fuel supply present
• ATP in muscles is limited
• Can only store 8-10 secs of ATP-CP
• Further regeneration of ATP comes from other systems

Anaerobic Metabolism (Glycolysis), Lactic Acid System
This pathway creates ATP from carbohydrates, of which lactic acid is the by product. It provides energy by the partial breakdown of glucose without using oxygen. The energy produced in this system is required for short, high intensity bursts of activity lasting only a few minutes, normally 1-3 minutes. The glucose comes from 2 sources:

• Blood glucose pool
• Liver and muscle glycogen (glycogen is stored glucose)

It is stored in the liver and muscles and in times of high intensity exercise glucose/glycogen is broken down and used for energy production. The break down of glucose required in this system give pyruvic acid, which in the absence of oxygen is further broken down into lactic acid. A build up of lactic acid (lactate threshold) will cause our muscles to stop contracting, muscle pain, fatigue and burning.

Aerobic Metabolism
This systems provides most of the energy needed for exercise of long duration. That is activities longer than 3 minutes. It is slower than the anaerobic system and requires the circulatory system to transport oxygen to the muscles to create ATP. It creates ATP from glucose, fats and protein. It supplies energy slowly and as it uses oxygen, carbohydrates and fats.


During exercise we will move through these energy pathways. The type of exercise will determine which system is used. As exercise begins we use the ATP that is stored within the muscles, once this is depleted we produces ATP via the anaerobic systems, as there is not enough oxygen in our muscles. Once there is an increase in our breathing and heart rate there is more oxygen available and we move into the aerobic metabolism system. We stay here until the lactate threshold is reached. Once here (lactate threshold) the body cannot deliver oxygen quickly enough to produce ATP and our anaerobic metabolism kicks in again. This is temporary and as lactic acid levels increase, our intensity decreases to help with the removal of lactic acid.


Ok.... Wow that is longer than I intended it to be. I'm going to leave it there otherwise you're not going to want to read it!!!

Joce

Want more reasons to exercise?

So while I was going through my book looking at what I was going to post next I came across some more benefits of regular exercise. I had gone looking for these while I was writing my last post, but somewhere along the line I skipped over them.
So here they are:

• Increase muscle strength and muscle mass
• Increase muscle flexibility and joint range of motion (ROM)
• Stronger bones, ligaments and tendons
• Decrease chance of injury
• Enhances posture
• Prevents osteoporosis
• Decreases resting heart rate
• Strengthens heart function
• Decreases blood pressure
• Improves the delivery of oxygen throughout the body
• Increases blood supply to the muscles
• Enlarges the arteries that provide blood to the heart muscle
• Improves immune function
• Aids digestion and elimination
• Promotes lean body mass; burns fat
• Improves mental outlook and self esteem
• Stimulates improves mental function
• Moderate to intense exercise may have an appetite suppressant effect

So there they are.

With exercise we decrease our risk of anxiety and depression which are two of the main reasons we use food for comfort. Exercise is the most under utilised tool we have at our disposal. How do we motivate more people to move their bodies, eat less processed food and experience all of the benefits listed. It isn't easy to motivate yourself to exercise and motivation doesn't just happen. Motivation is something that you, as an individual, need to work on every day!

There are 2 things that I have heard along the way to completing my courses and becoming qualified. I can't remember where, but they are:

• The hardest part of exercise is getting started
• If you don't feel like exercising, do 10 minutes. Chances are you'll keep going. But if after the 10 minutes are up and you still don't feel like it, then stop. I've applied this rule to my own training and I haven't stopped yet.

The Benefits of Exercise!!

So there are numerous benefits when it comes to exercise!!!!
Benefits including:

• Weight Loss
• Decrease Stress
• Decrease in symptoms of depression and anxiety
• Decreased risk of heart disease and certain types of cancer
• Boosts mood and energy levels
• Improves quality of sleep
• Increase in bone density
• Strengthens heart and lungs
• Improves quality of life:
• Decrease risk of diabetes
• Decrease risk dementia and Alzheimer's
• Decrease risk of hip fractures in post menopausal women
• Is the number one treatment for fatigue

A fantastic clip on the benefits of exercise as a medicine is 23 1/2 hrs by Doc Mike Evans:
https://www.youtube.com/watch?v=aUaInS6HIGo

It highlights the fact that all we need is 1/2 hour a day to reap the benefits of a healthier and happier life!

Joce

Why I became a Personal Trainer!

I started my journey to becoming a Personal Trainer in 2010 after becoming a mother for the first time. I found it difficult to find a gym (or PT) that wasn't too expensive and had facilities where I could leave Hayley while I did a work out. I also found the hours offered by the gym crèche limited, and with a husband in the defence force and often away for long periods, I found that I HAD to go during those hours or a didn't get to go at all.

I was also diagnosed with a hernia 8 months after Hayley was born, which I had repaired at the time. The recovery time for this was 6 weeks. A similar recovery to that of a caesarean. I often wonder if I had had the proper instruction when I returned to the gym or had personal training been an affordable option for me at the time, whether this would have occurred.

As I said in my last post, my husband is a proud member of our defence force and as such we move around every few years. In our early years as a couple I decided I would forgo a career in Human Resources to support his career in the Army. I have never regretted this decision! However, it means that I have had to find employment in each posting location!

I love exercise!!!! I love the feeling after training. Releasing the build up of stress after a bad day! I am also a sufferer of anxiety and if left untreated, depression. The best thing I can do for myself and for the prevention of my anxiety is EXERCISE! And it is by far the cheapest!!!

These factors lead me down the path to Personal Training. It seemed like a natural progression for me. It will allow me to be able to work of home in the future, where I can be close to my kids. I can take it with me wherever the defence force may take us!

My long term goal is to help those who want to change their lifestyle and get back in shape, particularly after having children. I want mothers to be able to bring their children with them, if they don't have anyone to look after them. I want to help expectant mothers on their journey through pregnancy and beyond.

I have had my Cert III and IV since 2011, but I have only just started working in the industry! This is because I found out I was pregnant while doing work experience. Then by the time I was ready to go back to work after having Ruby, we got posted to Melbourne!! So here in are in Melbourne, freezing our way through our first real winter in 5 years (winters in Brisbane don't count!). So I have found a great job and I am loving it!! The staff have a wealth of knowledge and I know I am going to learn so much from them, and I can't wait!

Over the course of this blog you will share my journey, my learning! This is the real start of my journey to becoming a Fitness Professional!!

Joce

Who am I?

Hi, my name is Jocelyn. I am a wife, mother, sister, daughter and friend.

My husband and I have been happily married for 5 years. During that time we have had our challenges, as we all do! Most of our challenges come from being a Defence family! We've done interstate moves, bush trips and deployments! We have been sooo lucky along the way to make new friends, try new adventures and see new places! Would I say that it's tough? Definitely! But would I change it? Nope! Not in a million years! You see, I am so proud of my husband! Of what he has achieved while serving his country, of what he's done and continues to do! He is an inspiration in many ways! He is a awesome father to our girls and he is a wonderful support to me!

I have 2 beautiful girls! Hayley is 4 and Ruby is nearly 2. They grow up so quick and both, without fail drive me insane at least once each day! They also fill me with happiness! I frequently experience anxiety about whether I am doing this whole parenting gig right!! I  hope and pray that I am and that I give my girls the best foundation possible to lead happy, and HEALTHY lives! To be the best they can be and to achieve whatever they set out to do in life!
And, you know what............. most of the time I think I do an awesome job!!!!!

My Family

And then there is ME! I grew up in a small town in Central West NSW, Yeoval! Heard of it??? I didn't think so. A place you may have heard of though is Dubbo. I went to school in Yeoval, played netball and spent a lot of time being carefree on the farm. We rode our bikes, caught yabbies, swam in the dams, learnt to drive and helped around the farm ALOT!
I am a lover of life and I will make the most of everything that comes my way!!

I hope you enjoy reading about my journey to becoming a Fitness Professional.

Jocelyn