Basic Principles of Endurance Training

Most people think that speed wins races in running, but I am not so sure this true. For me it is Endurance that wins races, or gets you to the finish line. Without a solid base of Endurance that is built up over hours and hours of training a runner would not be able to realise their full potential and speed. Even 100m sprinters have need of endurance.

So what are some of the basic principles of endurance training that one would need to build their training program on? In this article we will look at some of the basic principles of Endurance and why they are important. You will only get so good by going out and smashing a hard run, if you implement some of the principles you will discover hidden potential in you running that you never knew existed.

Before training our Endurance levels we need to understand the different energy systems that enable us to use that hard earned Endurance. Each energy system is different and directly effects a runner’s endurance. If Endurance is the engine, the energy systems are the fuel that run the engine. Utilising each energy system effectively will mean the runner is able to draw the most out of their endurance training that they possibly can. Even the best Endurance Training programs will mean little return without even a basic understanding of what energy is required at what level and how to train those energy systems in conjunction with the endurance training.

So what are our bodies Energy Systems?

Energy Systems

The energy systems, as the name implies is all about the production of energy in your working muscles. As your muscles fire at various points through training and racing energy is required to sustain them. This could be in a 10second sprint or a 24hour endurance run. For the body generate the energy you require there needs to be a combination of fuel, a spark and oxygen (the same as a combustion engine). Each energy system is evaluated according to their fuel and oxygen requirements. A fast effort will require a higher level of fuel in a shorter time period. The bodies ability to generate the fuel supply to satisfy the energy requirements in this system is different to that of a slower but longer effort, where the fuel is needed over a long period of time at a consistent supply to fuel the effort.

These are the two major energy systems that have to be addressed during your training. They are your aerobic and your anaerobic energy systems. The goal event and desired result in that event will determine what percentage of your program will be devoted to which. Aerobic energy systems will give you the fuel for the long haul and your anaerobic energy system gives you the gas for the shorter, faster efforts. Regardless of the runners goal event they will require training in both these systems to fully realise their endurance and speed potential.

Aerobic Energy System

Slow is smooth. Smooth is fst.

This is the foundation of any effort over 30 seconds and refers to your bodies ability to absorb and use oxygen to produce energy. The key to this energy system is Oxygen. The better your body is at absorbing and using oxygen, the higher the intensity will be which you can use while remaining in the aerobic energy system. A measure of aerobic fitness is your VO2 Max which refers to the maximum amount of oxygen that your body can utilise during exercise. Although VO2 Max is generally a product of your genetics and cannot really be trained a great deal (so the ability to absorb oxygen is pretty fixed), the ability to use that oxygen is highly trainable.

When you develop your aerobic system you can get more oxygenated blood to your working muscles. You also develop the ability for your body to use that oxygen that has been transported to your working muscles to generate energy. The more oxygen you get to your muscles the more your muscles are able to fire for longer at a consistent strength and pace.

Typically the way you develop your aerobic capacity is by fairly low intensity training. This is different for everyone and you need to determine where the crossover point is between your aerobic and anaerobic systems. This crossover point, or anaerobic threshold (AT) is important to know for two reason. Firstly because your aerobic training needs to be at an intensity lower than this point to get the desired training effect and secondly because this is the intensity that you should aim for as your race pace during competition. Any event over a few hours is best raced at the pace of where you remain at your aerobic threshold, going into anaerobic for too long will eventually cause you to ‘hit the wall’. As we will see a little further on the anaerobic system isn’t as sustainable as your aerobic system. AT is highly trainable and needs to be evaluated at least once a month during the training year as it changes as you build your aerobic capacity.

The power behind the aerobic system is the fact that your body can use stored fat as fuel. This enables the body to run for hours as our fat stores are massively greater than our carbohydrate stores. Training and racing at an aerobic level means there is enough oxygen available to burn fat as fuel, saving the much need carbohydrates for the faster, more anaerobic efforts during a race or training session. It therefore also holds true that as you increase your aerobic capacity you should also be able to use fat as fuel at higher intensities. This is wonderful news for the endurance athlete because as mentioned earlier our fat stores far outweigh our carbohydrate stores (which generally only last around 90mins before needing to be replenished), effectively burning fat as fuel means the duration of the effort is increased greatly.

Anaerobic Energy System

A hard anaerobic effort is always fun 🙂

This is the all out sprint effort energy system. It does not require oxygen to generate energy, but lasts for a very short period of time. Typically it only lasts for all out efforts of 30 seconds or less. It requires a fuel that is very easy to burn and therefore primarily uses carbohydrates (Glycogen) stored in muscles and your liver as fuel. As mentioned earlier it only has a limited supply so if an endurance athlete goes out too hard early on and depletes their carb stores they will have to replenish on the go with gels and energy bars. This is very ineffective because at this point while replenishing energy levels on the go it is very difficult to keep your energy levels at a stable level. You will dip low and then rocket high as the simple sugars are converted to energy, only to be dropped down again as your body uses up the fuel. This from a mental perspective can be very damaging and make an already tough event even tougher. At this level of effort your body isn’t able to convert energy fast enough to maintain the pace of the effort which only contributes to up-and-down energy loss mentioned earlier. Training your anaerobic energy system helps you get comfortable at this level of effort. It will be almost impossible to race an endurance event at this level for the entire time. There will be times on the route where you will go anaerobic to get up a sharp but short climb for example but ultimately you want to remain within your aerobic threshold for as much of the event as possible.

What this means then is in order to get faster over the long haul a runner needs to increase the intensity he / she is able to maintain at an aerobic level. This is the key to running well and running fast, speed work can only make you fast for so long. Having an aerobic base that can power a jet engine is the secret to running fast. So now that we understand a little more about the energy systems how would one look at structuring their program to train these systems and increase their endurance capacity?

Below we look at a broad outline on how a program could be structured, we don’t go into much depth on individual sessions this is purely how to structure it for the long term.


The first and most basic principle is that of periodisation, or splitting your training before an event up into parts or periods. You do this to allow your body time to adapt to the training load in preparation for an event. Periodisation allows for a gradual increase in the load in order to prevent injuries and build an endurance foundation. Once this has been done you can look to add intensity to your training regime. High intensity training too early on or ‘too much mileage too soon’ will ruin the consistency of your training through injury and over-training. Periodising your program helps you see which ‘blocks’ you are in and keeps you focused on the specific goals for each block.


The first part of Periodisation is dividing your year into periods or phases lasting anything from 4-8 weeks. Each of these seasons / phases have a specific purpose. In coaching we typically like to break the training year up into:

  1. Adaptation Phase (also known as Pre-Season) – This phase is very much focused on technique and getting your body used to training after an off season layoff. Training is not only sports specific and could include quite general training such as Cycling, Boxing, Stand Up Paddle Boarding or Crossfit.
  2. Base Phase (or Pre-Competitative Season) – This phase is sometimes broken into a Base 1 and Base 2 but in essence it is the phase to build aerobic capacity, to build the capillary system and mitochondria in muscles and start working on strength (not speed). A note on strength, this is to strengthen your muscles, tendons and ligaments for increases in distance and intensity.
  3. Speed Phase (or Competitive Season) – In the speed phase the intensity of the workouts increase to the your anticipated (or goal) race pace or greater. As with most things in life when you take on the one side you have to give on another. So when you increase intensity you have to decrease duration / distance. Sessions will be mostly interval based and you can anticipate this being a taxing phase.
  4. Recovery Phase (or Off-season) – Once you have completed your competition season it is always a good idea to take some time off. During this time you can still remain active but give your body and mind a break from a structured training routine. Do activities that are not related to those which you have spent a whole season training for. You will start the next season mentally refreshed and physically revived.

The actual duration of each phase and the specific workouts during each phase will be determined by the actual goal that you have. You would need to evaluate the requirements of the goal to determine what you need to do to reach it. If your race is 1 hour long your base phase is going to look very different (and will be much shorter) than it would if your race was a 7 hour race.

The start of the training year (Adaptation phase) will be determined by the date of the event that you are wanting to peak for. Start with the date (or dates) and work phases back from there.

Micro-cycles (also known as Mesocycles)

Once you have planned the big blocks, you need to split these further into smaller parts, known as micro-cycles. These cycles are also aimed at allowing your body adaptation time. You will typically work in 3 or 4 week cycles. Which works best for you should be evaluated based on your current fitness levels and the event that you are training for. A 3 week cycle generally works best when you require more recovery, such as when you are in the Speed Phase or if you are just starting training from a long layoff. Or even in the Adaptation Phase. A 4 week cycle works best when you require a cumulative training effect such as when you are in Base Phase and training for a long distance event where intensity isn’t very high.

A 3 week cycle would look something like this:

  1. Maintenance Week – Maintain load (intensity or distance) at a manageable level.
  2. Overload Week – Increase load (intensity or distance) to stress your body and cause adaptation.
  3. Recovery Week – Decrease load (intensity or distance) to below manageable level to allow your body to complete the adaptation that was triggered by the overload week.

A 4 week cycle would just include a second Maintenance Week before the Overload Week with a slight increase in load (intensity or distance) but still at a manageable level.

In conclusion, Periodisation is a structured breakdown of your training year into seasons where specific goals can be set and managed. The seasons are then broken down further into micro-cycles. This allows for a controlled increase in load which improves the chances of a consistent and sustainable training load. It also ensures that all the required energy systems are effectively trained enabling you to maximise. Keeping an indepth log of all your training is a great way of staying motivated as well as seeing where you are at with regards to your goals.