5 Energy System Training Methods for Obstacle Course Success

Obstacle course racing endurance training methodsIf you’re looking to improve your performance at your next Obstacle Course Race, focussing on your different energy system can see you make dramatic improvements.

This article will give you all the technical knowhow to achieve this. Plus our five specific training methods you’ll need to master.

OCR athletes need to build a huge aerobic engine. Let’s first of all kick this off with a clear definition of what Endurance training is.

Endurance training can be defined as building the efficiency & durability of each individual energy system. This can be done individually or collectively to improve an athletes overall physical fitness and work capacity.

High levels of endurance and work capacity are required for most sports although the “type” of fitness required and the predominant energy system utilised will be dependant upon the metabolic demands of the sport.

There are 3 types of endurance training

  1. Aerobic endurance – which can be defined as the ability to exercise continuously for extended periods, without fatiguing or tiring.
  2. Anaerobic endurance – the ability to perform high intensity work bouts for an extended period of time, e.g. speed endurance
  3. Muscular endurance – a muscle group is required to work continuously over a period of time e.g. grip strength complex.

Another definition of endurance training is the ability to work continuously at a high intensity for an extended period of time and therefore the ability to resist fatigue, so with that in mind we need to be clear on energy systems before we talk about anything else:

The 3 main energy systems

ATP/CP System

The ATP system only sustains ‘all-out’ exercise for 5-15 seconds.

Think powerfully exploding up a ramp wall or climbing over an inverted wall.

Its during this this time that the potential rate for power output is at its greatest. If activity continues beyond the point, then body has to rely on the glycolytic energy system to produce ATP.


The lactate system provides the bulk of ATP production during high intensity sub maximal efforts.

It acts as the dominant supplier of ATP in the period from around 15 seconds of maximal effort to around 60 seconds of high intensity sub-maximal effort.

During glycolysis, lactic acid is produced and hydrogen ions begin to form in the muscles which results in muscular contractions being inhibited during high intensity exercise.

The body can tolerate increasing levels of lactic acid only until accumulation rate is higher than the body’s ability to remove them, at which point exercise intensity will significantly reduce until the aerobic system takes over.


The aerobic system is responsible energy for sub maximal exercise lasting from a few minutes up to a few hours.

Its also involved in re-synthesizing ATP during recovery between high intensity efforts.

Aerobic fitness is critically important for obstacle racers and is also referred to as VO2 max which as you hopefully already know, is the maximum amount of oxygen in millilitres that can be used in one minute per KG of of bodyweight.

A higher VO2 max has been associated with exercise performance, especially in endurance based sports.

Energy system training helped Andrea get success in major OCR championships

The 3 energy systems NEVER work independently from one another.

Regardless of whether you’re doing very short very intense exercise or very light prolonged activity, all 3 energy systems are still working together although one or two will usually predominate.

Podium obstacle course racing is largely an anaerobic based sport which requires athletes to be good all rounders.

They need to be fast runners over 15k (9.3 miles). Be able to perform at high intensity anaerobic efforts transitioning repeatedly from run to obstacle without getting gassed out. They also need to posses phenomenal grip endurance for obstacles like low rigs & high rigs etc.

So with all that in mind, an athletes training programme needs to reflect the demands of the sport.

You get good at what you’re good at.

You see, if you’re ‘getting the race reps in’ or always do long slow running in your training then over time you’ll become very good at long slow running when you race.

Not ideal if you want to become a faster stronger OCR athlete.

If you always do short fast intervals then you’ll likely be very good at running fast for short periods but your speed endurance will suck! Plus too much high intensity interval training can be fatiguing and will be a heavier neural demand as well.

Its vitally important that we develop energy systems appropriately for obstacle course racing, based on the demands of the sport and the fitness level of the athlete.

Energy System Training

The glycolytic/anaerobic system will predominate hugely for a sport like obstacle course racing so it makes logical sense to invest most of your time into developing a good tolerance to lactic acid.

The more tolerable you can become to lactic acid, the longer you’ll be able to work at a higher work rate. Therefore prolonging fatigue both during a race and in training.

Although having said that, training the ATP/CP system and Aerobic system shouldn’t be disregarded and are still vitally important for an athletes endurance development.

Below are my five ways you can train the different energy systems…

LSD or Continuous training

Long slow distance or “continuous” training is primarily training the aerobic system.

You basically train long and slow with your heart rate around 60-70% of MHR. Its pretty important too as it strengthens your heart which is important if you’re involved in an endurance based sport!

A well developed aerobic base will also allow athletes to recover faster.

Continuous training should feel pretty easy too and you should be able to hold a conversation with some one without feeling like you’re gonna die. It doesn’t always necessarily have to be a run either, and definitely not if you are carrying an injury. A swim or a stationery bike can be just as effective provided you are working at the right intensities.

Fartlek Training

Fartlek is a swedish term that means “speed play”. Its blending continuous training with interval training so it can be a great way to develop an athletes endurance.

Heart rate can be anywhere between 60-80% of MHR during a Fartlek session. Unlike traditional interval training that involves specific timed or measured work to rest periods, fartlek is a more unstructured approach and the work rest intervals can be varied more.

Fartlek training is proving to be a popular way to train for obstacle racing due to the stopping, starting and running at varied paces, but only if its prescribed and applied at the right time in an athletes season.

Speed Endurance

Speed endurance is a useful way to to develop an athletes tolerance to lactic acid. This is important for an anaerobic dominant sport like obstacle racing.

The purpose of speed endurance is to prolong the amount of time at which a near optimal speed can be maintained. There are lots of different ways we can apply this but generally speaking we can break speed endurance up into 2 types:

Intensive endurance – which are 4-8 minute interval runs keeping HR at 70-80%
Extensive endurance – which are 8-12 minute interval runs keeping HR at 60-70%

Interval Training

Otherwise known as HIT, high intensity interval training is characterised as short, maximal (10-30s) bouts of work interspersed with short recovery periods.

Interval training is a proven way to develop speed for obstacle course racing. However its VERY demanding on both the neuromuscular and metabolic systems and should be prescribed correctly and only once the athlete has a basic level of conditioning and the running speed should be gradually increased over time.

There are many different types of HIT training protocols such as billet, tabatas & MAS methods, generally speaking though we can classify interval training into 3 types:

Extensive intervals – are 1-4 minute interval runs keeping HR at 80-90% for each effort

Intensive Intervals – are 15-30 second interval runs keeping HR at 90-100% for each effort

Maximal intervals – are 10-30 second interval runs maxing HR at 100% for each effort

A couple of sample interval training sessions to develop running speed & power for obstacle course racing might be…

  • 200m reps x 10 with 45 sec rest which would be an intensive/max intervals type session
  • 400m reps x 4 with 90 sec rest would be more of an extensive intervals type session.

Sports Specific/Special Training

This is energy system training whereby we expose the athlete to the type of training he or she will be doing during their race. We’re replicating race conditions more here.

We can also apply stress response simulation training here too. This is training skills in a pressured situation. After all, its one thing to perform your skills when you’re fresh and when the pressure is off, but OCR athletes also need to display coordination  & composure when they’re tired, grip is fatigued and when the pressure is on.

Sport Specific training for obstacel racing such as tough mudder and spartan

A typical sports specific OCR session is where we start to mix skills with aerobic output.

For example 30 secs of an obstacle skill into 30 seconds of running sprints, 30 secs of an obstacle skill into 30 secs of running sprints. Repeat that for 5 minutes. Then take a 2-3 minute rest. Then do another 5 minute block like that, perhaps pairing a different OCR skill with sprints.

We call this T.U.F Conditioning here at Unbreakable which stands for technique under fatigue.

The goal here is to train skills under fatigue. Then we replicate race conditions and to get used to transitioning from running to obstacle with an elevated heart rate.

This type of training is way more beneficial once the athlete has already built a huge aerobic engine from some of the above training methods. Most athletes delve into TUF conditioning way too quickly without first laying down a strong aerobic foundation.

Final Thoughts

When it comes to endurance training, there’s no real right or wrong way to train. But consider that OCR requires you to be very good at tolerating lactic acid therefore your endurance programme needs to reflect that.

If you do lots of short distances and fast intervals in your training then you’ll likely be fast but could be prone to gassing out towards the end of a race.

On the flip side to that, if you’re doing lots of distance and long runs in your training right now, then you’ll likely have a decent engine on you but your speed during a race won’t be up to scratch.

Balance is the key, and even though obstacle course racing predominates in the glycolytic/lactate energy system, its vitally important that we create a programme which trains all three energy systems simultaneously.

The above energy system training protocols are all extremely effective but will ultimately be dependant on what phase of training the athlete is in, what training age the athlete has, where they are in their season or macrocycle, and whether they want to specialise in short course or long course obstacle racing.

If you need help with your endurance training for OCR or would like to arrange a 30 minute coaching call then feel free to email sam@unbreakablecoachingsystems.com

In the mean time, Train hard & BE strong!

Sam Winkworth

About the Author

Sam Winkworth is the race director of the popular Dirty Rotten Scramble race series. He is also the head coach at the Unbreakable Project, designed to develop obstacle racers who want to podium on a world stage. He is also the creator of OCR Virgin designed to help athletes of all abilities train & prepare for their first/next OCR.

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