What Are The Three Energy Systems - Level 3 simple explanation

What are the three energy systems: Level 3 Anatomy Simplified

You need to know about the three energy systems as part of your Level 2 and Level 3 Anatomy and Physiology exams, and also to truly understand the planning of exercise and get great results with your clients.

It’s is important to know about it, yet so many trainee fitness professionals leave this to one side because the manual makes it sound too complex.

So, let’s keep it simple – Watch the simplified explanation here:

What Are The Three Energy Systems - Level 3 simple explanation

What are the three energy systems?

We have three systems in our body and they each create ATP under different environmental conditions.

These three systems are going to be represented by three sandbags in this video. Just ignore the numbers on it, but leave this one’s red and therefore we are going to use that as Aerobic. This one is blue we are going to use that as lactic acid system and then the purple is going to be Phosphocreatine or sometimes known as the creatine phosphate System.

What do the Three energy systems do?

These three energy systems are working all the time in our body to create ATP so that we can move, so we can live, so our organs can function, and that happens all the time for all three of them. However, when do specific exercises, with a specific demand on our body, as a result, we will rely on one more than another.

Creatine-Phosphate System: 

Let’s say for example we did something explosive, let’s say we are sprinting really hard or we are lifting something for just one repetition we would use our phosphocreatine system, which lasts for 10 seconds maximum

Lactic Acid System: 

If we have this intermediate time, this is 10 seconds up to 3mins we would use our Lactic Acid System, so that could be a 400-meter run, it could be something whereby you are doing a set of resistance training for 12 reps, that’s probably in the 10 seconds to 3 mins which is lactic acid.


We spend most of our time Aerobic, I’m Aerobic now, Your probably Aerobic Reading this. So, as a result, this Aerobic system gets used for anything that’s three minutes plus, and this is where we use it predominantly.

But just remember we are using all 3 all of the time 

Sometimes people find it very hard to understand the Energy Systems because its so tiny it’s hard to imagine that our body.

Drop your comment or your questions below this video about anything to do with energy systems so we can help you understand it better.

1.Which Energy System lasts for a maximum of 10 seconds in duration?
A) Creatine Phosphate System
B) Lactic Acid System
C) Aerobic
D) Type 2b

2. Which Energy System would be used predominantly in a 1-mile swim?
A) Creatine Phosphate System
B) Lactic Acid System
C) Aerobic
D) Anaerobic

3. Which exercise/sport will use the Lactic Acid System mostly?
A) Power Lifting
B) 400m Sprint Race
C) Marathon
D) Discus Throwing

Answers to the mock questions are :

Question 1= A, Question 2 = C, Question 3 = B

If you want more mock questions like this, then you can download more Free Mock Questions: DOWNLOAD NOW

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Hayley “what are the three energy systems” Bergman

Parallel Coaching

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