The term carbohydrate loading has been used since the 1960’s to refer to a nutritional strategy that maximizes muscle glycogen (carbohydrate stored in the muscle) stores prior to an endurance event. Current guidelines recommend an exercise taper (reduction) while following a high carbohydrate diet (7-12g/kg body weight) in the one to four days prior to competition. The benefits are apparently a 2-3% improvement in performance in events that extend beyond 90 minutes.
Just like we once though the world was flat and saturated fat was the cause of heart disease, carbohydrate loading is not necessary to maximize performance. Here’s why:
1. The goal of an athlete should be fat adaption.
In short, endogenous fuel stores from carbohydrate are limited. We have between 1600-2000 calories of muscle glycogen, whereas, even at 10% body fat, 72,000 calories, or 40 times that amount of energy stored in adipose tissue. The more fat adapted you become, the more you can tap into an almost bottomless energy reserve. On race day, this means less fuelling (read: less gastrointestinal [GI] upset) and minimal chance of “hitting the wall” or “bonking”, the extreme case of glycogen depletion all-too-common in endurance events.
Here’s how to become fat adapted:
- Fill your plate with good fats, protein and non-starchy vegetables.
- Cut out starchy processed carbohydrates.
- Make refined sugar free eating a priority.
- Reduce your fructose intake.
- Train “empty” with a “fat black” prior to your session (i.e. an expresso shot with grass-fed butter and/or coconut/MCT oil.)
- Watch your post-exercise nutrition. More on this to follow.
2. The goal of an athlete is post-training nutrition.
To naturally increase and maximize muscle glycogen stores, focus on your training and your post-training fuel replenishment. The time period for carbohydrate loading is actually what you do in the 60-minute window after your more intense or longer training sessions. Post exercise, your glycogen synthase enzyme, the enzyme which controls glycogen storage, is most active and what you eat counts.
There’s a caveat here though. Top up your glycogen stores by all means, but to prevent a strong insulin response and therefore optimize growth hormone levels for both recovery and adaptation of muscles, please stick with 30-45g of carbohydrates. Not sure what to eat? Start with my Breakfast Antioxidant Bowl and if your session was more intense or longer in duration, simply add half a banana. You definitely don’t need six slices of white bread, Gatorade or Up&Go.
3. Human physiology does not work the way some researchers and Dieticians would have you believe. Muscle glycogen stores are limited, and just like a sink that is full, the excess overflows. And where does it go? Fat storage. Or if you’re lucky, it gets eliminated via your bowels. Regardless, every gram of glycogen carries two grams of water, so you’re most likely going to put on some form of weight and even if it is water weight, you definitely don’t need the extra kilograms with you on the course! And please, don’t let anyone tell you this water weight is good for hydration. Extracellular and intracellular hydration are two very different things. Drink your water, lemon and Himalayan salt for hydration levels please.
4. Have you ever tried to consume 7-12g/kg body weight of carbohydrate in one day? It is actually almost impossible. If you weigh 60kg, that’s 420-720 grams of carbohydrate in one day! Current guidelines are actually appalling as to how to achieve this – and I quote “In order to consume the necessary amount of carbohydrate, it is necessary to cut back on fibre and make use of compact sources of carbohydrate such as sugar, cordial, soft drink, sports drink, jam, honey, jelly and tinned fruit.” There is no way such refined sugar and frankenfoods can help performance. It’s almost like common sense got thrown out the window with the introduction of carbohydrate loading.
5. Just like the golden rule “nothing new happens on race day”, nothing new happens in race week. You’re now training less, so you eat less. Simple. Your plate should consist of nutrient dense food from good fats, protein and predominately non-starchy vegetables. By all means, add in a small amount of good-quality starch from sweet potato, fruit or quinoa post-training, but keep it to one portion or half a cup maximum. As you become more fat adapted, your muscle glycogen stores can still be optimized with a lower carbohydrate, higher fat approach. For more information, I recommend “The Art and Science of Low Carbohydrate Performance” by Jeff Volek and Stephen Phinney.
In summary, carbohydrate loading is a thing of the past. It only leads to extra water weight, the potential for body fat accumulation and an increased likelihood of GI upset and “bonking” on race day. Say no to the pasta party. Focus on your fat adaption and post-training nutrition and your performance will speak for itself.
Australian Sports Commission. (2009). Carbohydrate Loading. Available: http://www.ausport.gov.au/ais/nutrition/factsheets/competition_and_training/carbohydrate_loading. Accessed: November 12th, 2013.
Born, S. (2011). The Top 10 – The biggest mistakes endurance athletes make. Available: http://www.hammernutrition.com/hnt/1273/. Accessed: November 12th, 2013.
Cordain L, Friel J. (2005). The Paleo Diet for Athletes. Holtzbrinck Publishers.
Fogeloholm GM, Tikkanen HO, Naveri HK, Naveri LS, Harkonen, MH. (1991). Carbohydrate loading in practice: high muscle glycogen concentration is not certain. British Journal of Sports Medicine, 25(1), 41–44.
Phinney SD, Bistrian BR, Evans WJ, Gervino E, Blackburn GL. (1983). The human metabolic response to chronic ketosis without caloric restriction: preservation of submaximal exercise capability with reduced carbohydrate oxidation. Metabolism, 32(8), 769-76.
Phinney SD, Volek JS. (2012). The Art and Science of Low Carbohydrate Performance. Beyond Obesity LLC.