5 Reasons to Become more Metabolically Efficient

sarah cuff Run Faster, Run Recovery, Run Stronger, Running Performance 16 Comments

After a good half-year of struggling with energy, performance and weight gain, I decided to try something – a solution to my woes if you will – that isn’t readily taught in traditional sports nutrition. As a result it helped me to bounce back from months of lacklustre performance and rather extreme fatigue. Plus those extra pounds that had been slowly creeping on finally got lost. After the initial relatively quick bounce back (within about a month) where I finally felt energized and like myself again, I’ve settled into a slowly but surely things just keep getting better kind of mode.

Taking all this information and experience, last month I led 24 participants through the first Become a Better Fat-Burner: increase your metabolic efficiency workshop. To be honest – I was a bit amazed it sold out because I’ve never before really talked about what metabolic efficiency is or why you’d want it. It’s a huge topic. Nevertheless, the workshop content was enthusiastically received and participant feedback told me it was exactly the information people were looking for, if not more so. This served to convince me that while discovering how to become more metabolically efficient may be unconventional, it’s also ‘cutting edge’ and definitely a topic people want to learn more about!

What is metabolic efficiency?

Metabolic efficiency is a measure of your body’s tendency to direct calories consumed into fat cells versus burn calories consumed as fuel – as well as what percentage of carbs (glycogen) versus fat (fatty acids) is utilized during activity at various intensities.

Those with a metabolic disposition to burn most of the calories they consume as fuel will have plenty of energy for physical activity, and few calories will be stored as fat. Despite few calories being stored as fat, they can easily access the fat they do have for energy. They’ll be lean and active. And they’ll easily and happily eat in moderation.

However, those with the metabolic disposition to send calories they consume into storage as fat tend to gain weight easily and have a terrible time trying to lose it, despite trying to train consistently. Although they have tens of thousands of calories worth of energy stored on them in fat cells, their muscles have trouble accessing it for energy. They have little energy for physical activity – getting out the door is often a struggle (yet through sheer willpower and probably some sugar and caffeine they do usually mange to complete their workouts!). They also tend to have a never-ending appetite.

While I don’t know where you where you are on the scale of metabolic efficiency, I can tell you that everyone stands to benefit from becoming more metabolically efficient. It will undoubtedly improve your body’s ability to utilize fat for fuel instead of keeping it locked away in fat cells – or worse, unnecessarily storing more of it in said fat cells.

The benefits to becoming more metabolically efficient

1. Improved energy

One of the most immediate changes I noticed when I began eating (and training again) in a way that encouraged my body to become more metabolically efficient was how quickly and dramatically my energy levels improved. I went from hardly being able to get my butt out the door for a short easy run to being able to run longer distances again without feeling like I’d just been run over by a truck. I went from needing a nap everyday to becoming productive in the afternoons again!

It makes sense. As your body becomes more efficient, calories consumed are used for energy right away instead of stored as fat. Part of my struggle for energy had been because my body had been taking much of the food I was eating and shuttling it off to fat cells right away instead of using it for energy. As a result I was hungry all the time, with only short energy bursts following foods rich in easily digestible carbs. It was honestly a nightmare – and needless to say turning things around felt like nothing short of a miracle.

2. Improved body composition

Along with improved energy, the other immediately noticeable change that took place (as a result of my body not shuttling calories consumed into fat storage anymore) was that I stopped gaining weight. In fact, I very quickly (within the month of March 2017) shed most of the ~8lbs I’d gained over the previous 6 months. Since then I’ve been slowly but steadily continuing to move in the leaner and lighter direction.

We all have a set point – a weight we can reach in a healthful way (without deprivation) where we’ll perform our best and feel our best. Eating in a manner to become more metabolically efficient naturally allows your body to reach its set point.

3. Less chance of GI distress during exercise 

Athletes fuel their workouts with both glycogen (carbs) and fatty acids (fat). Higher intensity activities tend to use more carbs, particularly in athletes who are not as metabolically efficient. This is problematic as our carb stores are limited to about 90 minutes (possibly longer when fully carb-loaded) at moderate intensity – think running a marathon (and only about 20 minutes for high-intensity exercise). Additionally the digestive system essentially ‘shuts down’ during intense exercise, rendering digestion of food during exercise difficult for some athletes.

However most activities can be fueled almost entirely by fatty acids. Exercise of moderate intensity that lasts more than 90 minutes has traditionally required the athlete consume 30-60 grams of carbohydrate per hour, which can lead to GI distress, nausea or discomfort for many runners. Good news – it turns out the more metabolically efficient you are, the less gels, chews and sugary fuel you’ll need to consume during exercise – and therefore, the less chance of GI upset.

Take a look in the chart below at the variance between athletes who are low to somewhat metabolically efficient and those who are relatively to very metabolically efficient.

VO2max  low to somewhat metabolically efficient relatively to very metabolically efficient 
25% (low intensity, can sustain all day) ~55% and up to 72% of energy coming from fat Up to 100% of energy coming from fat
65-75% (‘easy’ pace, can sustain 1-2 and up to 8 hours in a well trained athlete) ~30% and up to 56% of energy coming from fat ~88% and up to ~98% of energy coming from fat
85% (10k to half marathon pace, can sustain for about 60 and up to 90 minutes) ~10% and up to 30% of energy coming from fat ~56% and up to ~76% of energy coming from fat
95% (interval paces – can sustain for only 3-5 minutes) ~2% of energy coming from fat Up to 23% of energy coming from fat

4. Improved performance

Both weight loss and freedom from GI issues will result in improved racing and athletic performance. Becoming more metabolically efficient will improve VO2max (via weight loss) and remove GI issues that can cause runners to have to slow down or in extreme situations DNF (did not finish).

Greater energy will also contribute to improved performance. A runner who is making best use of calories consumed means the body is turning most if not all into immediately useable energy – and thus will be able to take full advantage of pre-exercise meals and any nutrition that is consumed during activity.

5. Improved feelings of satiation

Foods with a high glycemic load both decrease metabolic efficiency and tend to throw us into what can feel like a never-ending vicious circle of needing to eat every few hours (or every hour, or every few minutes!!) otherwise that ravenous hunger sets in again. I can remember actually feeling panicked if I didn’t have food with me when I left the house. Feeling like if I didn’t eat something NOW I was literally going to die of starvation (okay that might be a little extreme… but it was close!!).

Turning things around and being able to go hours without feeling hungry (having taught my body to use its’ own fat stores for fuel) has been such a relief. I love food, but I don’t like feeling controlled by it!

As you can see, there are so many benefits to becoming more metabolically efficient. Just in case you’re wondering HOW to actually do so, I’ve just opened registration to my second Become a Better Fat-Burner: increase your metabolic efficiency workshop. Here I’ll dive into the 4 ways to become more metabolically efficient (2 nutritional strategies and 2 training methods) complete with all the science behind each strategy and method… And a whole lot more!

For those of you who aren’t in Vancouver BC, I’m tossing around the idea of compiling the workshop material into an online course. Let me know if you’d be interested in such a program in the comments below… And then stay tuned!

To deliciously healthy food and stronger faster running… Cheers,


Sarah J Cuff, RHN

Sources for V02max chart: Volek, Jeff. The Faster Study, 2015 – https://www.ncbi.nlm.nih.gov/pubmed/26892521 (accessed July 2017); http://zachbitter.com/blog/2014/04/takeaways-from-the-faster-study.html (accessed July 2017); Burke, Louise. Clinical Sports Nutrition, 4th ed. McGraw-Hill, 2010; The Crossover Concept https://halevylife.com/metabolic-testing-know-vo2max-guide/(accessed July 2017)

Comments 16

  1. Hi Sarah, I am interested in face to face workshop. Last time I was not able attend the workshop due to planned vacation. I am hoping, September workshop date will be better for me.

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  2. I really want to do this course but I’m 90% sure that I will be away on this date. An online course would be amazing! Cheers!

  3. I’m in Vancouver, but I’d definitely be interested in an online course with takeaway handouts! Think this is a topic that many runners are interested in!!

  4. Bummer, running a half marathon in Toronto on Sept 16th, but like 90% of the replies so far I would totally be into an online workshop. Or the next workshop in Vancouver after the Sept one. Cheers.

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