top of page
Recent Posts
Featured Posts

Chapter 1 - Energy Systems

Training for most people doesn’t come easy and is a real trial and error process. You are basically learning how your body responds to training stress and how much rest you need before you can put it under stress again. Basically you have to pay for every effort and the older you get the slower you recover.

When and how to train easy and when and how to train hard makes more sense if you understand the energy systems involved in producing energy for movement.

This article identifies the time frames and fuels used for each of the three energy systems: If you didn’t want to read the article, a quick summary might look something like this:

  • Immediate – Anaerobic energy system occurs in absence of oxygen, and produces energy very quickly. Very short intense efforts. 10 seconds or less like 100m sprints.

  • Short term – Anaerobic energy system using stored glycogen. Used in high intensity, moderate duration activity lasting 30 seconds to 3 minutes. Produces lactic acid which is what causes the burn in your muscles during a 400m track rep or 1k bike repeat.

  • Long term – Aerobic (occurs in the presence of oxygen) produces large amounts of energy but does it slowly. Low to moderate intensity in efforts over 5 minutes. It’s the dominant energy system in triathlon training and racing.

None of us have time to waste by going into a session without a specific goal and you want to make every session count. To get the best out of your program you need the right balance of “Immediate”, “short term” and “long term” conditioning in the right proportions, at the right stage of the program. You also need to take into account your stress levels and recovery abilities if you are going to make it work. Trial and error is important but there are a few obvious traps to avoid. One of the biggest traps would be spending too much time using the Immediate and Short term energy systems or training with too much intensity too often leading to fatigue, overtraining and injury.

A commonly accepted ratio of low intensity to high intensity is 80/20. So if you spend 10 hrs a week training then 8 of them should be at low intensity. The biggest gains in fitness are made in the low intensity zones, including your ability to perform at maximal effort for extended periods of time, like in races. Some people will refer to this as a lactate threshold but that term is slowly disappearing as too many people disagree on where this threshold actually is. On a personal level I found my olympic and sprint distance times fell dramatically the season after I started training longer and slower and targeting a long course race. I have seen the same thing happen with other athletes I’ve worked with too.

So, if the biggest gains are made with low intensity training then why go hard ever? From what I can tell it’s because the body responds to variety, and with high intensity training there are neuromuscular gains to be made in the form of speed, strength and technique. On the downside it uses a lot of energy and injury risk is higher. For this reason it’s used sparingly early in a program or during base training, and more frequently in the build towards the goal race. To put it into terms that most of us can relate to high intensity training is only the icing on the cake. You can eat it without it but it’s better with it on. MMM cake!

We probably should go into a bit more detail about training zones at some point but “conversation pace” is a very simple method to identify where low intensity training tips over to moderate intensity. Once your respiratory rate starts to labour and you can’t hold a fluent conversation you are creeping out of the sweet spot. If you want to put a more scientific name to it you can call it your “respiratory threshold”. Google it, it’s an actual thing. Moderate intensity has a place but usually it’s just a waste of precious energy and it’s often called the “grey zone” or the “mushy middle”. Go easy or go hard. Finding these sweet spots is tricky and there are many limitations to HR training which is why training with power is so popular.

That kind of leads us in to training zones and how to find them. But I’ll leave that to next time.


Search By Tags
No tags yet.
Follow Us
  • Facebook Basic Square
  • Twitter Basic Square
  • Google+ Basic Square
bottom of page