In the previous newsletters, we’ve spoken about the equipment you need for a minimalist gym set-up and we wrote an article on the exercise selection for a full body strength workout. Today we will tell you a little bit more on how to train the aerobic (or oxidative) energy system and how to create workouts for it.

Let’s do a quick recap of the energy systems we use in sports.

  • There is the ATP CP energy system also known as the anaerobic a-lactic energy system which primarily uses creatine phosphate for fuel. This energy system is used for resistance training and short, powerful efforts lasting up to 20 seconds. The term “a-lactic” means without lactate, while “anaerobic” means without oxygen.
  • In this energy system, we do things like heavy lifts (1 RM), all-out sprints for short distances where the power output is maximal.
  • Then there is the anaerobic glycolytic energy system that primarily uses lactate as a fuel source. It is defined by efforts that are at an unsustainable level of work and with the presence of lactate. Lactate is the byproduct of intense work and will begin to accumulate at a significant level as intense efforts are extended out beyond 15-20 seconds (you know that burn you feel in your muscles). This type of training is work that typically lasts 30 seconds and can be extended out to 2-3-4 minutes (depending on your level of training). It is progressed by starting with power and moving towards endurance.
  • Finally, there is the aerobic or oxidative energy system that accesses a massive store of virtually unlimited energy. In simple biological terms, the aerobic energy system utilizes fats, carbohydrates, and sometimes proteins for re-synthesizing ATP (cell energy) for energy use such as training or exercise. It’s of course much more complicated, but this energy system uses oxygen as its primary fuel source.

Energy system training

Energy system training is a massive subject in the fitness and athletic development industry. While many people understand the basics of what energy systems training is, they have trouble with the application of this knowledge in determining the workouts they want to integrate in their fitness program. And that applies to most of us. When left on our own, we have difficulties determining what to put in our workout and we often just do something without having any idea what the intent of the workout actually should be.


When we say aerobic energy system we need to think long ‘sustainable efforts’ and ‘pacing’. This energy system can extend our work for hours. An example of work that would be performed by the aerobic system includes low intensity but long-duration activities like a 60-minute row or long-distance running. Anything that is classified as aerobic is long in nature but low in intensity. In other words, the action is sustainable for long(er) periods of time.


The overall benefits of training the aerobic energy system are the following:

  • Cardiovascular development
  • Pulmonary development
  • Muscular development
  • Learning to be patient (pacing… remember?)

Apart from the above, there are great benefits to sustained aerobic work for the average person who is concerned with vitality. For example:

  • improved immune system,
  • improved cognitive function,
  • improved digestion, and
  • an improved disposition.

Aerobic work is also beneficial for people who are on the pursuit towards higher levels of performance. Such as:

  • increased mitochondrial density (this will allow you to train faster and longer),
  • increased capillary density (which improves the delivery of oxygen and nutrients to your muscles and allows you to clear waste products faster),
  • improved fuel utilization, and
  • faster recovery between intense pieces of work.

So, whether you are a weekend workout warrior or if you are serious about raising your level of fitness, the development of the aerobic system should always be a foundational aspect of your training program.

Principles to apply when designing training for the aerobic energy system.  

When it comes to aerobic training there are a couple of principles to keep in mind. These are…

  • Interval training
  • ‘Slow to Fast’ and ‘Long to short’
  • Cyclical first, mixed modal later
  • Pacing strategies / patience

Interval training:

When talking about interval training, we should keep in mind that the pace per interval should be the same as the pace we should be able to hold on for 4 times the duration of the interval. So, if you do intervals of 15 min run, then you should do those at the pace you run for 1 hour. The mistake many people make is that when they do intervals, let’s say 4 sets of 15 minutes, they go all out in the first set, barely hang on in the second set and then completely die in the third and the fourth set. Speed has its place but with aerobic development, you try to do repeatable efforts. When it comes to mixed modal we should keep a steady round time per set (and how many of us go all out the first round, try to hang on in the second and then start dying as of the third 😊).

‘Slow to Fast’ and ‘Long to short’

Aerobic development happens from long and slow(er) efforts all the way to short and faster efforts. You also have to develop it in a very gradual way. With that, I mean that you have to give it time. Personally, I work in blocks of 8 weeks. So if I start with a 60 min piece at the sustained effort, I integrate that in my programme for 8 weeks before I switch to a shorter time domain of 2 pieces of 30 minutes … another 8 weeks of that and then again a switch to 15 min, then to 10 and so on…

Cyclical first, mixed modal later.

When starting to build your aerobic base, it’s better to start with cyclical sustained work, rather than with mixed modal (different exercises incorporated in the same piece, such as an AMRAP). The reason for this is that it takes time to know your body and that it’s much easier to control your pace in a mono cyclical piece (eg running, rowing or assault bike) rather than doing it with mixed modal work. It takes time before you acquire the knowledge to know how your body will react towards different types of exercises and that is unique to every person. I have exercises that from an aerobic perspective don’t go together very well, whereas others where I have no problem with the transitions and can manoeuvre with (relative) ease from one exercise to the other.

Pacing strategies /patience.

What one often sees is that, especially in mixed modal work, people tend to go out way too fast in their first rounds and start with a pace that is not sustainable for the entire piece of work. It is better to start a bit slower, stick to the pace or sustain it and when you have some extra fuel left, keep it for the end.  Thus, don’t be too hungry for the pain…. patience is of the essence.

There are a couple of other principles but for someone who wants to start their aerobic development, the above should suffice for now.

Finally, a few words on who should do what when it comes to aerobic effort, and there are a couple of factors that come into play here:

  • Starting point: Some people have already a solid aerobic base, others don’t.
  • Genetics: some people are naturally more aerobic whilst others are naturally more powerful.
  • Goals: some people train for a marathon or a triathlon, whilst others want to do well in CrossFit workouts or just want to train for longevity and health.

Baseline, every individual is unique, so don’t just start copying what others do. Know your starting point, align your training with your goals, apply the principles and you’re good to go.




Author: Peter Koopmans