This article is part of Endurance Planet’s ultrarunning article series. If you have questions, comments or feedback about “Nutrition and Energy Needs of Running”, please leave it below in the comments section…
As you may know there are typically three types of nutrients that you’re going to need as energy sources. These are carbohydrates, fats, and protein. Actually whether you’re walking, jogging, going at it in full throttle, or just standing still, you’re body is burning all three at the same. But the consumption for each occurs at different rates.
Level of effort affects the rates of consumption
These three types of nutrients are stored in your muscles and function as the immediate sources of energy. Other parts of your body also store these fuels in one form or another and are your reserve tanks so to speak. When the intensity and duration of your efforts are such that they used muscle stored fuel, it turns to reserves in other parts. Besides that, another go-to source will be whatever food you may still be in the process of digesting.
At a relatively slow pace it’s usually fats that get consumed more than carbohydrates, and protein is used up the least. As you increase your pace or put in harder effort, consumption of the fuel stored in your muscles increases and the ratio changes with more carbohydrates being burned relative to fat. If one were to rank the three nutrients in terms of demand, carbs get first place because it only takes a few hours of intense effort to burn up muscle and liver stored carbohydrates.
Carbohydrates and fats
Carbs may have a higher rate of consumption but the advantage is that compared to fats, it outputs a little more energy. At the maximum level you can absorb and deliver oxygen to your muscles and given you haven’t depleted your muscle carb stores, you can actually produce more energy. Take note however high carb consumption can only be maintained for a limited time. This is the reason why sprinters and competitive ultrarunners will always have a greater energy need for this nutrient.
This doesn’t mean that comparatively slow runners can take carbs for granted. Slow or fast, when you run out of muscle stored carb and don’t quickly replace it, you’re still going to hit the wall. Carbs in the muscle actually also help you burn fat more efficiently. A runner, who has trained poorly, particularly in the area of pacing, may likely suffer the disadvantage of not having adapted a more effective way to burn fat and established a slower rate of carb consumption. Another thing about getting depleted of muscle carb is that it may trigger a higher rate of protein burning and that kind of metabolism breaks down muscle tissue.
Training efficient consumption
The point of including your fuel system into your training and learning the proper ways to pace yourself during a race is to learn how to establish a flowing balance between your energy consumption and replenishment. This is one of the reasons why it’s a good idea to start slow and use a run-walk strategy. You control fuel consumption better and give your muscles a chance to continuously restock what it’s also continuously using up. You can’t simply rely on your body’s reserve tanks, not especially in distances of 100 kilometers or 100 miles.
Do you have questions about the nutrition and energy needs of running, or what you’ve read so far? Do you have any ultrarunning pointers of your own to add? Please leave your feedback, comments and questions below, and we promise we’ll respond.