“Fat is my fuel, Alfred.” That’s what I told Alfred when he first started enquiring about my peculiar eating habits. We were staying in Pietermaritzburg with our company swimming team that was about to swim the Midmar Mile the next day. While others in the team were carbo-loading on tasty macaroni cheese and “liquid-bread”, I was eating roast chicken and salad. Alfred was curious. I told him how a low-carb, high-fat Banting diet might affect 3 things which could lead to improved athletic performance: energy levels, recovery and weight loss.
“Oh wow,” said Alfred in near disbelief at what I told him. Alfred was already more than curious…
Energy levels: Swapping to a bigger fuel tank
By adopting the Banting diet, Alfred will be able to increase the energy in his body available for exercise by as much as 20 times.
Imagine that you had a car that could only take you 30km on one tank of fuel. After every 30km of driving you had to go to the fuel station to refill. But if you’d never had any other type of fuel tank you’d never know that you were wasting a lot of time and energy doing this. If one day, someone told you that your car actually had another fuel tank that would allow you to drive much further – 20 times further – would you switch to using that fuel tank? You might do the maths first and see that you would be able to go 600km on this new fuel tank! At which point you’d most likely laugh in that person’s face and tell them to not be ridiculous and waste your time. You’re a busy person and probably need to be getting to the station quickly because you are low on fuel. Or would you try make the switch to test this ridiculous fuel tank idea out?
This is what we hope the Banting diet will do for Alfred. He will go from using his Glycogen (Carbohydrate) Fuel Tank, that gets its fuel from sugars and starch, to using his Fat Fuel Tank. By reducing the sugar and starchy food in his diet, Alfred’s body will naturally switch (keto-adapt) to start using fat as a fuel. He will then go from having a tank that holds about 2000 calories of energy (in the body’s store of glycogen) to one that holds 40 000 calories of energy (in the body’s store of fat).
Source: The Art & Science of Low Carbohydrate Performance – Volek & Phinney
Seems like a good switch for someone who’s planning on running a 90km marathon, wouldn’t you say?
Recovery: Rolling with the punches
Training for a marathon is not an easy activity for the body and the amount of training you can do before a race is closely linked to how quickly your body can repair, maintain and build new muscle and other tissues between training sessions. The Banting diet will allow Alfred to recover much more quickly between training sessions by building and growing muscle and other important tissues, rather than breaking them down.
What happens if you are running a really long race and you’re still using those old carbohydrate fuel tanks for energy? There’s a good chance that you might run low on fuel. But not to worry, your body is great at making a plan in times of trouble. So what it might do to help keep you going is break down some protein to provide energy for your muscles.
But isn’t protein your body’s building block for growth and repair? It is, so you need to refuel your Carbohydrate Tank so your body doesn’t have to use it for energy supplies.
By switching to using his Fat Fuel Tank Alfred is going to have more sustained energy levels and his body will rather use its protein for growth and repair, allowing him to recovery more quickly between training sessions and thus increase his strength.
Another way to improve recovery is to reduce the load that your legs have to carry. This is achieved through weight loss.
Weight loss: Kilos be gone!
We hope that Banting will help Alfred reach his goal of weighing 70kg or less before this year’s Comrades Marathon.
Imagine you were just about to run a race and then someone handed you a 7kg bag of flour that they wanted you to carry for the entire race. All 90km. Do you think it would affect your performance?
This is what Alfred had to deal with when he discovered that he had gained 7kg since he ran the last Comrades Marathon (that was three weeks ago when he weighed in at 81kg). Alfred has not been spending his time in the gym over the last year so this extra mass is certainly not muscle… A year’s worth of less training than normal and resting because of injury had led to an increase in waist size for poor Alfred.
By switching to the Fat Fuel Tank, Alfred will start to burn up this fat much quicker than a normal athlete as it has become his energy source rather than just an extra weight that his body has to lug around. (Check out Alf’s weight loss progress here.)
Alfred’s goal for this year’s Comrades is to finish it sub-9 hours. He started his training much later than in previous years, and so believes that he can’t realistically hope for better than that. But switching to a bigger fuel tank will give him the sustained energy to improve his performance. Better recovery between training sessions will allow him to use the short preparation time that he has left much more efficiently. And the weight loss will result in a much improved power-to-weight ratio, essential for improved performance. Maybe sub-9 is going to be a walk in the park for Alfred…
Alfred’s final word on the question of “Why Banting?”was this…
“People who eat vegetables only are called vegetarians. But what do they call someone who just eats everything and anything??? I need to choose a new identity… I think ‘Banter’.
As a Banter I hope to do it (Comrades) and inspire the other Banters!”
Lots of confusing scientific papers read and written by the authors of these two books: Why We Get Fat: And What to Do About It and The Art and Science of Low Carbohydrate Performance, whose concepts I have highly simplified (and probably slightly bastardized) for this article. This blog article also gives quite a sciency explanation of “switching your fuel tanks” or keto-adaptation, if you’re interested.