My Facebook feed has been flooded lately with stories about Tour de France cyclists going low carb.
Or is it high protein?
Whatever is going on, it seems to help them run well too!
While I’m not sure you can say that these elite cyclists have eschewed all carbohydrate-containing foods, the trend away from processed carbs to whole foods is intriguing.
So if they’re going low carb does it mean they’re now butter, cream, MCT oil after starting the day with BPC?
Dr James Morton, head of nutrition at Team Sky and an associate professor in the Faculty of Science at Liverpool John Moores University explains:    
We promote a natural approach to food. Our riders eat food that grows in the ground or on a tree and protein from natural sources.
They need energy, but they also have to stay lean and healthy with a strong immune system. A natural diet is the best way to achieve this.
Fat is important for everything from energy release and muscle health to immunity, but by eating the right food the fat takes care of itself. The riders eat eggs, milk, Greek yogurt, nuts, olive oil, avocados and some red meat for a natural mix of saturated and unsaturated fats.”
To achieve optimal weight, Dr Morton asks the riders to “periodize” their carb intake by eating more when they train hard and cutting back when they’re less active.
They routinely train in the morning after eating a protein-rich omelette, instead of carbohydrate-dense bread, to encourage their bodies to burn fat for fuel.
So how does low carb real food thing work?
According to Dr Terry Wahls, it seems that nutrient density is a vital part of maximising energy output.
To produce ATP efficiently, the mitochondria need particular things. Glucose or ketone bodies from fat and oxygen are primary.
Your mitochondria can limp along, producing a few ATP on only these three things, but to really do the job right and produce the most ATP, your mitochondria also need thiamine (vitamin B1), riboflavin (vitamin B2), niacinamide (vitamin B3), pantothenic acid (vitamin B5), minerals (especially sulfur, zinc, magnesium, iron and manganese) and antioxidants. Mitochondria also need plenty of L-carnitine, alpha-lipoic acid, creatine, and ubiquinone (also called coenzyme Q) for peak efficiency.
If you don’t get all these nutrients or if you are exposed to too many toxins, your ATP production will become less efficient, which leads to two problems:
Your body will produce less energy so they may not be able to do everything they need to do.
Your cells will generate more waste than necessary in the form of free radicals.
Without the right nutrient sources to fuel the ATP production in the mitochondria – which in turn produce energy for the cellular processes required to sustain life – your mitochondria can become starved. The cells then can’t do their job as effectively.
So let’s look at the macro and micro nutrient analysis of Chris Froome’s “rest day breakfast” (pictured above). The analysis indicates that it does very well in both the vitamins and minerals score as well as the amino acids score.
If we throw in some spinach Froomey would improve the vitamin and mineral score of his breakfast even further. The addition of spinach increases the nutrient balance score from 57 to 77 while the amino acid score stays high.
Froome’s wife says eating more protein has been one of the keys to losing weight and building muscle leading up to the tour. Getting a quarter of your calories from protein is more than the 16% most people consume, however with 65% of the energy coming from fat you could also call this meal low carb, high fat, or even “ketogenic” depending on which camp you’re in.
This simple but effective meal would be a pretty good option for just about anyone. Froome’s breakfast ranks well regardless of your goals. Based on the ranking system of meals for different purposes it comes in at:
- #10 (with spinach) and #31 (without spinach) out of 245 meals analysed for the low carb diabetes ranking,
- #18 and 52 on the therapeutic ketosis ranking, and
- #26 and 64 on the overall nutrient density ranking.
It seems it’s not just the low carbers, “ketonians” and people battling diabetes who are training their bodies to burn fat more efficiently. Maximising your ability to burn fat is critical even if you are extremely metabolically healthy.
The chart below shows a comparison of the fat oxidation rate of well-trained athletes (WT) versus recreationally (RT) athletes (who are not necessarily following a low carb diet). The well-trained athletes are clearly oxidising more fat, which enables them to put out a lot more power (measured in terms of their VO2max). It seems that your ability to efficiently burn fat for fuel it a key component of what sets the elite apart from the amateurs whether you call yourself vegan, ketogenic or a fruitarian.
While carbohydrates help to produce maximal explosive power, it seems that the glucose turbocharger works best when it sits on a big power fat fueled motor. According to Peter Defty (who spent the last couple of years helping 2016 Tour de France second place getter Romain Bardet refine his ability as a fat adapted athlete using his Optimised Fat Metabolism protocol), fat can yield more energy more efficiently with less oxidative stress which requires less recovery time.
Dr Morton also understands the importance of keeping carbohydrates low to maximise mitochondrial biogenesis and to access fat stores. If you want to learn more about his thinking on the use of diet to drive mitochondrial biogenesis you might be interested in checking out his array of published papers on the topic.       On the topic of carbohydrate intake Morton says:
Amateur riders are taught the importance of carbohydrates for training and racing, perhaps too much actually.
From our research at Liverpool John Moores University, we now know that deliberately restricting carbs around carefully chosen training sessions can actually enhance training adaptations.
But then of course we must ensure higher carbohydrate intakes for key training sessions and hard stages in racing.
I believe this concept of periodising daily carbohydrate intake is the most exciting part of sports nutrition in the last decade and our challenge now is to address how best we do this practically.
Essentially, exercising your mitochondria in a low insulin and low glucose state forces your body to adapt to using fat for fuel and to use glucose and oxygen efficiently and effectively. 
Not only is this useful for endurance athletes and people battling diabetes, training your body to use fat and oxygen more efficiently is also claimed to be important to minimise anaerobic fermentation which is said to increase your risk of cancer.  
Many of us struggle to cope in an environment of excess energy from low nutrient density highly insulinogenic food. If we can’t obtain the necessary nutrients from our food to efficiently produce energy our bodies seek out more and more food in the hope of finding the required nutrients and enough energy to feel OK.
Our bodies do their best to use the energy that we give them, but they are working overtime to pump out insulin to store the excess energy that is not used. Over time our bodies adapt by becoming resistant to insulin to stop the excess energy being stored in our liver, pancreas and eyes when our fat stores in our muscles and belly can’t take any more. Then to overcome the insulin resistance the body has to pump out more insulin which makes even less of the energy we eat available for use.
When we call on our mitochondria to produce intense bursts of energy with minimal fuel (i.e. fasting) or glucose (i.e. low carb), we force our bodies to more efficiently the limited carbohydrate. Suddenly our bodies become insulin sensitive.
Recent studies indicate that people who are fat adapted are able to mobilise higher rates of fat at higher exercise intensities.
With a higher reliance on fat, they are able to conserve the precious glucose for explosive efforts.
Then, when they really need the power, they have both fuel tanks available to cross the line first… and second!
post updated July 2017