Metabolic Reserve, Part 1: What is it. And how can we prevent it diminishing.

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Metabolic Reserve, Part 1: What is it. And how can we prevent it diminishing.

Our lives, and the world around us, just seem to be getting busier and more demanding. And unfortunately, in many cultures, we even boast about how busy (read ‘important’) we are! We spend more time at work, more time sitting in traffic, give more effort into maintaining our market share with increasing competition, and are exposed to information and choices that grow exponentially by the day, in every area of our lives. To the point where even a simple supermarket shop can become a stressful exercise in decision-making skills – does this contain synthetic additives? is my child allowed this in their lunchbox? is this the brand my partner gets? are the animals treated ethically? is this from a sustainable source? can i find a cheaper option?….. Our minds are offered little time to rest.

So is it any wonder so many of us have experienced ‘adrenal fatigue’ (more increasingly being referred to as hypothalamic-pituitary-adrenal dysfunction, HPA-D), and are left with little energy to get involved in anything outside of work, even s*x, let alone find the energy for exercise!. On top of the fatigue, loss of libido and decreased tolerance to exercise, with HPA-D our brains get foggy, sleep becomes difficult, our muscles ache, we wake tired and reach for more caffeine and sugar, but our immune system is now compromised, we become prone to accidents and illness, and our once positive personality becomes a rollercoaster of unrecognisable mood swings, short fuses, and an inability to cope with even small tasks, we may even become depressed, and our relationships and work suffer dearly… I’m speaking from experience and science here, having experienced a complete shift from ‘competitive marathoner’ to ‘all of the above’, in what felt like a few short days, back in 2008.

So it was with great pleasure I stumbled across the concept of metabolic reserve in an article by Functional and Integrative Medicine expert – Chris Kresser, because I feel it is a great way of looking at our lives in terms of what will drain our ‘battery’ (Chris’s analogy), and what will charge it. This can enable us to move out of a fatigue cycle, and start to build to a point where we can opperate at maximum power, efficiency, ease, and enjoyment.

Metabolic reserve also gives us a template to ‘re-charge’ (luckily human batteries have that ability) if we’ve been draining power from our ‘personal device’ frequently, but forgetting to bring the cord, the wall plug, or just forgetting to plug it in to the ‘electrical source’…

Often you’ll notice your device running a bit slower as the battery gets closer to zero, so hopefully (as your ‘personal device’ doesn’t have a battery indicator) you can recognise that immediately, and ‘plug in’.

However, if you’re always letting the battery get to this dangerously low, lets say the 10-20% point, then its not going to take much – maybe a stressful presentation – to run it flat. So the idea is to re-charge every day, many times a day, especially if you’re draining your battery heavily.

The other thing to remember if you’re constantly hitting ‘flat’, is that it takes a long time to get a measley 10% life, which is still not going to give you a lot to draw from. Hence why you might feel ok for a bit, but then completely hit the wall again after a short stint of exercise… In my case, I may have been opperating at say 40% battery, but running 100+km/week was a heavy drain, so my battery reserve probably needed to be higher. Make sense?

Technically, metabolic reserve can be described as the long-term capacity of cells, tissues and organ systems to withstand repeated changes to physiological needs.

Interesting? Maybe, but I think it’s easier to view it as your own personal battery that runs the entirity of your mind, body and consciousness.

So on that note, over the next 2 blogs, I’m going to give a brief overview (and by no means a comprehensive list) of battery ‘drainers’ and battery ‘chargers’ which you have some control over.  Your mission is to make sure they’re at least in balance. But if you’ve already hit empty, or you feel you’re getting low, or you know there’s going to be a few additional ‘drainers’ in the immediate future, you’re going to need to focus more efforts into ‘charging’ to get that battery up.

This is the basic fundamentals to living a #perkynz life, and I will elaborate on each in future blogs.


Poor Diet:

  • XS of processed foods, sugar, refined carbohydrates, leading to poor blood sugar regulation – a trigger of HPA-D
  • Inflammatory foods – this will depend in part on your particular food sensitivities, but will include XS alcohol, trans fats, refined carbohydrates, sugar, omega 6 fats, and often gluten, dairy, MSG and synthetic preservatives. It can lead to ‘leaky gut’ and chronic inflammation which may predispose you to autoimmune conditions, inflammatory arthritis and many other disease states. Add to this the effect of pharmaceuticals you may be taking for these conditions, and you’ve got a mass drain on the system
  • Dehydration – I can’t tell you how often I used to see people in private practice who were chronically dehydrated and sapped of energy because of it. You can fix this today!
  • XS caffeine – partially dependant on your bodies ability to metabolise caffeine, this will place extra strain on the liver.
  • Vitamin and mineral deficiencies, including iron, B-vitamins, Vit D…

 Psychological Stress:

‘Percieved’ stress is the important word here, as what is stressful and energy sapping to one person (eg public speaking) can be energy giving to another. And while some stress is crucial for our growth and development, chronic stress will put our body in constant ‘fight or flight’ mode, creating a cascade of hormonal responses that seriously drain our batteries. You know in yourself which stressors are detrimental and will need to consider these individually. In this list I have focused on common emotional and psychological stressors that we can choose to eliminate, or learn to deal with better.

  • relationship stress – partner, friends, family
  • financial stress
  • job stress
  • moving house
  • poor self-esteem
  • depression / negative emotions
  • travel
  • clutter/disorganisation – of the mind and environment
  • change and unpredictability
  • new experiences

Physical Stress

What is considered physical stress will depend partly on genetics, where you are at in terms of battery life right now, as well as fitness, age etc. Listening to your own body in terms of how it feels during and after exercise, as well as recovery times and muscle soreness is crucial. On the flip side inactivity will also drain your batteries (see exercise chargers), so finding balance and addressing ‘chargers’ will help you maximise what you can manage without draining metabolic reserve detrimentally.

Exercise more likely to be a ‘drainer’:

  • running/cycling/swimming at a moderate-high intensity
  • cross-fit
  • racing of any kind
  • boxing classes
  • bootcamps
  • circuit classes (note: high intensity interval training or HIIT can sometimes be tolerated even when metabolic reserve is reduced)
  • moderate cardiovascular exercise especially above 60 mins – swimming, cycling, aerobics etc at moderate intensity
  • sitting all day long

Sleep Disturbances

A multitude of factors come into play here, but one thing is certain, unless this is adressed, the best diet in the world won’t counteract it’s potentially catastophic effect on our energy, and just about every body system. Possible causes:

  • travel
  • shiftwork and erratic sleep/wake schedules
  • XS exposure to blue light devices before bed (smartphones, laptops etc)
  • alcohol
  • stress
  • inadequate exposure to sunlight first thing
  • magnesium and nutrient deficiencies
  • breathing issues / snoring
  • partner disturbance
  • poor sleep setup – synthetic bedding, poor quality pillows/mattress, too hot/cold, noise, light


In my next blog we’ll be discussing ‘Methods to charge up your battery’, which is clearly a necessary part to the equation! So I look forward to sharing this information with you.


By | 2017-07-14T15:11:02+12:00 April 10th, 2017|Exercise, Lifestyle, Nutrition|0 Comments

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