Here is the thing, the body prioritises carbohydrates ahead of fat for fuel. Although we always burn a combination of carbs, fat and protein, if carbs are in abundance, our system will consume these first. If we constantly consume carbs at a level we never deplete we will store excessive carbs, fats and proteins in the diet as fat, simple. Periodised Carbohydrates is the key.
Over time our ability to burn fat for refuel reduces, this leads us to low blood sugar when carbohydrates are low, bringing on suppressible hunger. That’s right, a hunger for more carbs. And so we continually store fat, never burning it.
OK the next issue. When we exercise we have been conditioned to consume high sugar drinks and bars. Again stopping us from burning fat, the reason why most of us exercise. Guess what, it’s not working!
Tradition diet programs teach us that it is a simple calories in / calories out problem, so eat less, exercise more = health weight. Well this does not work. Simply put, most of our daily calories are used outside of exercise. that is breathing, thinking, digesting. Cut the calories and the first thing you lose is your vitality, metabolism and motivation.
For athletes, a dependency on carbs puts limits on you endurance sustainability. You can only digest a high level of carbohydrates for a limit amount of time. The higher the dependency, the short the digestive period sustainable. This is most relevant to athletes competing in events over 8 hours. Lower carb racing also has the benefit of reducing the volume of blood and water to digest carbs.
Carbohydrates aren’t bad, the are just misused. Carbohydrates are great for high intensity exercise, allowing us to reach high levels of intensity and force. Great for sprints, gym workouts etc.
How to periodise Carbohydrates
To periodise carbs we look at our daily, weekly, and if we do endurance training, our training blocks.
To ensure we don’t gain insidious weight through continuous slow weight gain we need to ensure our body remembers how to burn fat for fuel. To do this we eat three balance meals a day containing a balance of Carbs, fat and protein which gives us our recommended calorie count. I recommend not counting calories as with the right balance we stop eating when full. We then avoid eating for 4 to 5 hours until the next meal. In this time our carbohydrates will deplete and our bodies will begin burning fat. Initially this is hard as our bodies will not be fat adapted, but hang in there.
After two weeks you body will learn to burn fat and the mid meal hunger will disappear. Before long you will find snacking is not needed and quite often your desired meal sizes reduce too.
For those not on a rigorous training program, it is good to go low carb (<50 grams for the day) once a week. This will re-enforce fat adaptions and consume some of those hard to move fat cells. It is important to replace the calories with healthy fats or else your vitality will drop and you will burn less!
Periodisation for endurance athletes
Athletes should follow the daily and weekly periodisation model with the weekly low carb day being on their recovery day.
Additional to these we a training block periodisation.
- Pre-season Keto phase – Pre-season I recommend a week for low carb ( < 50 grams per day). It is important to replace the calories with healthy fats or else your vitality will drop and you will burn less! This period helps you drop some of that weight picked up in the off-season and primes the body to burn fat at low intensity.
- Block recovery phase – During recovery weeks of a periodised program I recommend spending 3 to 4 days on low carb (< 50 grams per day) to promote fat burning as a fuel and to reduce inflammation. As training volume is reduced, fat intake should stay the same as in training. In this period eat as much non starchy vegetables as you want to promote recovery. Exclude vegetable fiber from the 50 grams carbs count.
- Peak phase –This is taper. During this phase we do not reduce carbs, we keep these to a normal training level. As training is reduced we effectively carb load through training reduction, not increasing carbs!
Using Carbs in training sessions
I recommend using carbs strategically in training sessions. By strategically I mean when there is an adaptation benefit or you need to familiarise effects for racing.
My general guidance is:
- Short aerobic sessions (Up to 2.5 hours) – No Carbohydrate before or during session. If this is a morning session, start fasted. Consume Water and electrolytes only. Post exercise continue normal daily eating plan.
- Long aerobic sessions (Over 2.5 hours) – 30 grams carbs per hour taken from start of session. Support absorption with water and electrolytes. Consume healthy fat meal with some real food carbs (fruit) on completion.
- Race simulation session – Consume you racing specific carbs, usually 40 to 60 grams per hour. Support absorption with water and electrolytes.
- High intensity sessions – Carbohydrates help us reach high levels of intensity. Consuming 20 grams of carbs before a HITT , sprint or heavy gym session will assisting getting the maximum adaptation.
- Mixed Sessions – In sessions which are mostly aerobic with some hard intervals and surges I recommend adhering to the short or long aerobic protocol, but take 20 grams of carbs approx 30 seconds for surges or efforts which will last more than 10-20 minutes.
For longer aerobic sessions I recommend taking some carbs with you if you are not sure you are fully fat adapted. Adaptions can take a couple of weeks, be cautious!