The last blog introduced the different ways we can increase the stress to the body by reducing oxygen supply to the tissues. We call this desaturation, and we measure it with a pulse oximeter. By reducing the oxygen supply or energy to the cells this stress will cause adaptations which can be utilised by humans to increase their performance and this is what we will be unpacking in this article.

We will also start our discussion around the central governor hypothesis, which is a theory involving the brain and its past experiences putting limits on our performance. If we take the brain and introduce new experiences, this lifts the limits on the central governor and we can reach a new potential.


C02 tolerance

There is another important thing we need to discuss which we will see during some of the types of training I have mentioned in previous posts. This occurs when we reduce or stop our breathing, exercise at altitude or when we do not allow the body full recovery from a particular exercise.  What we see is a build of up of Carbon Dioxide in the body, which is the waste product of cellular respiration.

At rest and with normal respiration, free from lung disease, we get a reading of the exhaled breath of 35-45mmHg of C02.

The body is very sensitive to changes in C02, it’s the reason why you cant hold your breath for a long time if your untrainedyou have not done C02 tolerance training before. It’s the crushing feeling that forces your body to take a breath and it’s the stimulus that causes diaphragm contractions like these here:




Recent work with William Yang, increasing his ability to hold his breath during high intensity sprint racing.


Most athletes I work with have to undergo some form of C02 tolerance training first in order to get past these contractions and painful stimuli to ensure your body can enter into states of hypoxia. This is William Yang and we are currently working on his ability to deal with CO2 triggers at high heart rates, this work will be intense for 8 weeks and then form part of his warm up routine.

Its also a great tool as an athlete to have under your belt. If you have taken your body and mind to these extremes, then your ability to perform will soar. This is the central governor hypothesis at play. From working with Alyce Burnett, a kayaker who holds her breath during the first 7 seconds of her race in order to generate the power she need off the start, to Kai Lenny and Ryan Hipwood having to hodl their breath in intense big wave situations, to Cameron McEvoy doing a 50m sprint no breath or reducing the stress of the 3rd turn in a 200m free. This stimulus can be trained and should be at this level.

But if you’re a newcomer to this type of training, and we ask you to perform high intensity exercise with breath holds, then you are likely to fail due to high levels of C02, before we start to see reductions in 02 delivery to the tissues. That’s OK, your early in your breath training journey.


Try this:

  1. Plank, breath all the air out and hold your breath and do 5 pushups.
  2. Return to plank position and take one breath in, breath all the air out straight away, hold, and do 5 push ups.
  3. Repeat until you have done 30 push ups


How did you go?

Don’t forget to post your results to my Instagram page so I can collect some data. Let me know how many push ups you could do.


Just a reminder:

Red Blood Cells are the cars driving around our blood vessels. They carry our Oxygen!

Haemaglobin are the car seats where the Oxygen (02) sit

Saturation (%) is the number of empty seats in the cars on our roads. EG: If it’s a 5 seater and we have 4 passengers then we are 80% saturated. If you hold your breath or exercise at altitude you may reduce the 02 delivery to the tissues and we see a reduction in the amount (%) of oxygen we are carrying. You will need a pulse oximeter to try this.

Commonly in our consultations we will see saturation levels of just under 80% if they are well trained. That means that there is a spare seat in the car, it doesn’t seem like much but 02 carrying capacity is very delicate when we go below 80%.



SO here is where we run into a hurdle together, there is positive research out there for altitude training with the live high / train low concept. But evidence for Intermittent Hypoxic Training (IHT) for performance is contradicting and is an emerging science. There is an art form in delivering breath interventions to different athletes, different sports and to people with different pathologies. There is no clear prescription out there to achieve all the benefits you can which is why you must work with an expert.

Breath training programs need to be individualised and specific!

So the way around this is I will present some concepts from research and we can discuss this in future posts. I certainly will make my view points known, happy and willing to discuss this openly!


  1. High-Intensity, continuous exercise in Hypoxia – (altitude models)

Eg: Hypoxic conditions stress the body which cause downstream changes in energy metabolism. These appear to be dependent on how your genetics interacts with hypoxic conditions, which again highlights the need for the test – re-test protocol all training programs should have.


In this review they also looked at task failure under high intensity, continuous exercise in hypoxia and concluded that task failure was not due to the muscles failing, but instead a reduction in the recruitment of muscle fibers which suggests a signalling issue. This introduces the idea of central mechanism governing fatigue which deserves a chapter by itself. But it essentially tells us that the brain, and its past experiences have control over the human body and can dictate the play even though our muscles are ready and capable of doing the job. If its new territory for the body and the mind we will always be holding back, even if we dont want too.

A good example of this is if you suffered from a traumatic water experience early in your childhood you may have difficulty over-coming this. The brain remembers the emotions and trauma and this plays out until you train yourself to overcome this. We must train the brain in all situations so we can perform at our best. To take your performance to the next level, do something different!


So you need to train and be comfortable in all possible situations that may arise


This is an important concept and one that lies at the heart of breath training, whether you are a Hoffer and reducing your C02 levels or you are a slow breather and wish to retain C02, there is an esoteric component that is the essence of life itself. The breath has a link to the hind brain and uniquely can dictate some of its behaviour as we will hopefully unpack slightly in this article. Breath training hardens the brain and allows you to reach your new potential, removing the limitations that we put on ourselves.




  1. Repeated Sprint Training in Hypoxia

EG: Repetition of short (<30sec) “all-out” sprints with incomplete recoveries in hypoxia. Think of doing a beep test (shuttle test) with breath holds.

This method was developed to overcome the reduced training intensity involved with the above model (high intensity continuous). If you try to train continuously at high intensities in hypoxia, you fail quickly and hence your overall training intensity has been reduced.




So, in this model we are able to achieve some states of hypoxia at the tissue level. This is the stimulus we need to evoke a response in the body. The body recognises a reduced delivery of Oxygen (article) and adapts to improve performance. It says “OK we are performing exercise with less oxygen, how can we change and perform better?”

Adaptations may include:

  1. Improved glycolytic pathway (a more efficient utilisation of Oxygen as an energy source)
  2. Improved blood perfusion (the body thinks that the blood cant get to the tissues so it improves supply, more roads for the car to drive on)
  3. Hypoxic sprints forces the body to utilise anaerobic pathways which may lead to a peripheral fatigue resistance


In any case there is a great meta analysis review of this type of training Brocherie et al 2015 which confirms that this type of training is superior to normal repeated sprint sessions.


  1. Strength Training in hypoxia

Lets un-pack whats happening first…..

More research is needed, but when you train in hypoxia and use breath holds, it certainly feels very different to traditional strength training for obvious and not so obvious reasons. The theory is by exercising with reduced 02 supply, the body is producing more metabolites and anabolic hormones in response to this increased stress.

In previous posts I have discussed methods to achieve this, and the research by Manimmanakorn A describes using tape to occlude vessels using Kaatsu bands and also breathing air that has had the oxygen removed from it. Either way, I have been experimenting with my athletes and on myself with some new techniques which include the push up 5 x 5 test above. Adding some element of breath hold sprint or strength training will improve your performance.



Breath training has many applications in performance, pathology and the mind. We are seeing the introduction of specific programs to people around the world to deal with common problems such as asthma, anxiety and poor sleep. Increasingly, breath training is being used to stress the body, challenge the mind, and allow individuals to adapt to this stress and improve their performance.

There are no specific routines or programs to achieve improvements, you must be tested and delivered a program from a breath training expert. If you have any questions or queries please get in touch!