An Introduction to LCHF for Athletes

Dietician Katie KingI’m an athlete – I need lots of carbs for energy. LCHF couldn’t possibly work for me…. Right?

I hear you. It’s all you’ve ever known. Pasta parties, carb loading and that magic number of ‘grams per hour’ you endeavour to consume during each long training session and event. A quick look at the AIS website for carbohydrate recommendations: 360 grams daily. And more than that leading up to an event and more again out there during the race.

I find this advice difficult to swallow… pardon the pun. Here are three major reasons why I don’t agree:

    • Firstly: In order to come anywhere close to the recommended daily carbohydrate intake, you must include a lot of highly refined carbohydrates from heavily processed foods. These sources tend to be high in gluten, additives, preservatives, artificial flavours, colours, sugar and unfermented processed soy. Every single one of these ingredients is inflammatory to the body, damaging to the gut lining and may inhibit the immune system. Furthermore, I really can’t imagine having much room leftover for essential fats and proteins if I am required to ingest this many carbohydrates.
    • Secondly: When carbohydrates are the primary component of every meal, blood sugar and insulin levels rise then fall like a rollercoaster. These insulin surges meal after meal, day after day, year after year – will lead to insulin resistance down the track. This is the pathway to other far more serious conditions including metabolic syndrome, type 2 diabetes and obesity. Yes, even athletes develop these conditions.
    • Finally: When we exercise, our heart works harder to pump blood to the extremities of the body, including muscles which require nutrients and oxygen in greater amounts. The blood vessels to these outer extremities dilate whilst the vessels around the stomach and kidney constrict. This makes the whole process of digestion difficult. Last time you had an energy gel or a snack during an event…. How did it go down? Did it hesitate half way? Feel like it might come back up again? Is it any wonder?

Overall, we know that running a marathon, or doing a triathlon or any type of athletic event is physically stressful – the very process causes a great deal of inflammation within the body. So why would we turn to copious amounts of highly refined foods that further exacerbate these responses?

Traditional sports dietetics advice is built on the premise that we use glucose (sugar) as energy. Specifically, we use up the glucose that is stored as glycogen in the muscles and liver during endurance events. There are approximately 2500 calories worth of energy stored in the form of glycogen within our bodies. This is our ‘gas tank’ during sporting events. The whole premise of ingesting carbohydrate as you move is to prevent the tank from running out of gas, otherwise known as bonking. But 2500 calories isn’t going to get you that far. Whilst we all burn calories at slightly different rates, a 70kg man running at 10km / hour will use up approximately 800 calories per hour. Do the math and this means that he’s got just over 3 hours of fuel in the tank…. Or 30km. Ever seen someone hit the wall in a marathon at 30km? I bet you have…. it’s an all too familiar state of affairs. And unless you have a cast iron gut you aren’t going to keep up with your own refuelling requirements. So there’s a high chance you’re going to bonkville too.

Good news – there’s an alternative. What we have been ignoring for a long time is that in addition to those 2500 calories of stored glycogen, we have another great source of energy. Body fat. And seriously, who is going to say no to burning off a bit of body fat during an endurance event? Not me. The cool thing is that even a lean athlete will have at least 100,000 calories worth of energy available within stored fat sources and we are able to train our bodies to tap into these reserves. It’s that simple! Yes… THIS is what all the fuss is about!

Imagine the potential for athletes who have a continuous fuel source at their disposal? There are lots of athletes out there who are experiencing the benefits; Bevan McKinnon, Sami Inkinen, Bruce Fordyce, Jon Olsen, Zach Bitter and Karyn Hoffman are some of the big names living, breathing and succeeding with this method.

But much more than just performance, I believe that this approach is essential for athletic longevity. It promotes the inclusion of foods in their most unrefined state, with moderate amounts of protein and nourishing anti-inflammatory fats, both of which are essential for cells, hormones and life in general. Interestingly, these ‘real’ food sources are also the richest in nutrients including vitamins, minerals, antioxidants and phytonutrients. As athletes it is absolutely imperative that we are getting an abundance of good nutrition to promote fast recovery, support our immune systems and dampen down inflammation within the body.

The LCHF approach for athletes does not necessarily severely restrict carbohydrate intake. For some athletes, nutritional ketosis may be worthwhile considering (more on that here). However, for most people, LCHF is about retraining the body so that it becomes more metabolically efficient.

Let’s consider the Respiratory Quotient (RQ): a method for testing and measuring how much energy is coming from carbohydrates and how much is coming from fat during an exercise session. An athlete with an RQ of 1.0 is solely relying on carbohydrates during exercise, whilst an athlete with an RQ of 0.7 is burning fat exclusively. Obviously, intensity of output does play a part here but can you see the benefits of sitting closer to the 0.7 score as opposed to 1.0 on this scale? An athlete who is able to tap into some of his or her existing fat stores is going to be capable of a higher output for a longer amount of time with less fuel. This is a win / win in my book. Achieving optimal metabolic efficiency for your own sport and your own individual body may make you ‘bonk proof’ and means that your endurance is no longer left to chance.

Fat adapted athletes tend to experience advantageous body composition changes. Often losing a few kilos of fat while maintaining or increasing their lean body mass. Many report quicker recovery (a real food diet has superior nutrient density).

This article serves as an introduction to LCHF fuelling for athletes. The foundation of this approach is real food, as unrefined as possible. When you switch to a real food diet and away from gels and sugar laden sports drinks your carbohydrate intake will automatically reduce and your fat intake will increase.

There are other key concepts for you to consider such as the ‘train low, race high’ approach, nutritional ketosis, rethinking your electrolytes and fluids and the possibility of fasted training. This website provides many resources to kick off your research and for further help you may want to get in contact with any of the recommended health professionals for a tailored plan of attack.

Good luck on your quest for life long athletic longevity and your journey to being bonk proof!

Katie King

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