If you’re an endurance athlete, you’ve heard the term “Carbo Loading”. The objective of carbo loading is to fill your body with fuel (carbs) for next day’s event. This typically includes eating a lot of complex carbohydrates like pasta, bread, or rice 12-18 hours prior to your event. You can learn how to best carbo load, including quantity and timing, in these articles:
There is a lot of emphasis placed on what you eat before your event but not enough taught about the importance of replenishing fuels immediately after your workouts. Did you know that “Carb Replenishment” throughout your training is as important as carbo loading? What is carbo replenishment? It’s very simple. It’s refilling your tank with high quality carbohydrates and proteins. The critical piece of information I don’t hear or read enough about carbo replenishment is that it needs to happen within the first 30 minutes after all your workouts. This especially important during the weeks leading up to your event.
As an athlete, you don’t gain all your fitness in the days before your event. Fitness is gained gradually over time. The same can be said about training your digestive and refueling systems. Making carbohydrate replenishment within the first 30 minutes after your workouts a habit will train your body to absorb fuel resulting in higher quality workouts, greater endurance, and better recovery.
When you workout or race, the primary fuel used for the first 60-90 minutes is glucose stored in the muscles. As the muscle stored glucose is depleted, it’s replenished from glucose stored in the bloodstream. As the bloodstream is depleted, it’s replenished from the liver. As the liver is depleted, your body has 2 choices for glucose replenishment: body fat and consumed carbs.
Your body will utilize body fat, also known by athletes as stored energy, if your intensity level is within Heart Rate Zones 1-3. The lower the zone, the greater utilization of fat. Once your intensity levels reach 4+, you’re running strictly on carbs in the body. You can continue in 4+ zones only for a limited time; until you run out of body stored glucose. But I can consume carbs while racing. Yes, you can in the form of gels or bars for example. Your body’s fuel tank (muscles, bloodstream, and liver,) when full can hold around 2000 calories of glucose. While your body can burn upwards of 700+ calories per hour, your digestive system can only replenish 250 calories per hour; regardless of how much you put in your body).
Even if you are completely full of carbs (glucose) at the beginning of an event and you maximize carb consumption (250 calories per hour) during your event, your body will eventually run out of fuel if you don’t supplement with fat. The higher the zone you sustain during your event, the quicker you will empty your tank. This is why pacing yourself at lower heart rate zones is important for longer events. Keeping your race intensity in aerobic heart rate zone utilizes fat to supplement the 250 calories per hour you’re taking in. I like to use the bank analogy with my athletes. Your body’s fuel tank (that can hold around 2000 calories) is your checking account. Your body’s fat stores can be considered your saving. Your event is like shopping. As you shop, you deplete your checking. The faster you shop the quicker you deplete your check and need to replenish from your savings. The bank will accept checking deposits for 30 minutes immediately after the shopping is done. You can make still make checking deposits after 30 minutes, but it takes a lot more time to process those deposits and your checking may not completely full before your next shopping spree.
Training your body to absorb fuels quickly by replenishing within 30 minutes after all f your workouts will result in higher quality workouts, greater endurance, and better recovery.
Source: Some suggestions included in this article were influenced by Endurance News; a Hammer Nutrition Newsletter.
Coach Tony is a TriDot coach with the following certifications; Ironman Certified Coach, USA Triathlon Certified Coach, Slowtwitch Power Cycling Coach, Certified Slowtwitch FIST Bike Fitter, Total Immersion and US Masters Swim Instructor. www.coach-tony.com
