Improve Your Fuel Efficiency
As mentioned previously, one of the critical benefits of running at your aerobic threshold is that you're able to conserve glycogen. When the aerobic system is your primary energy contributor, you're able to burn fat as a fuel source. This allows you to conserve your glycogen stores.
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It's also possible to teach your body how to be more efficient at burning fat as a fuel source at your aerobic threshold. The more efficient you can become at burning fat while running at marathon pace, the longer and faster you can run before bonking.
Therefore, a critical component to your marathon training should be improving your ability to burn fat as a fuel source when running at marathon pace. To accomplish this, you need to deplete your glycogen stores and then challenge your body to run at marathon pace in training. By not having readily available muscle glycogen to burn, your body is forced to burn fat. Consequently, your body will become more efficient at using fat as a fuel source.
You can accomplish this goal by implementing fasted long runs, running back-to-back glycogen-burning workouts or fast finish long runs. I'll detail the execution and theory behind these workouts in next month's article.
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Increase Muscular Endurance
The final component to marathon training is to develop the muscular endurance in your legs to run the full 26.2-mile distance. The challenge: running the full marathon distance in training is not recommended due to how long it would take to recover. So, we need to get creative in training to simulate the fatigue of running a marathon, and to develop the muscular endurance needed to go the distance.
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To accomplish this, you need to implement what coaches call the theory of "accumulated fatigue." Basically, this means that the fatigue from one workout accumulates and transfers to the next so that you're always starting a workout or a long run a little tired from your previous training. This type of training helps you develop muscular endurance without needing to run the full marathon in training.
One way to introduce accumulated fatigue is to increase your weekly mileage. Not only does this develop your aerobic system, but it also leaves you with less glycogen and more tired legs for your subsequent runs.
My favorite method of introducing accumulated fatigue into marathon training is by buttressing the long run against a shorter, steady-paced run the day before. For example, you may run 1 mile easy, 6 at miles marathon pace, 1 mile easy on Saturday, and then complete your full long run on Sunday.
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Because of the harder running on Saturday, you start Sunday's long run not at 0 miles, but rather at 6 or 8 miles, since that is the level of fatigue and glycogen depletion your body is carrying over from the previous run.
Now that you understand the theory behind marathon training, we can discuss the specific workouts and long runs that will help you take your performance to the next level. Stay tuned for next month's article, when we'll discuss how to use these concepts to take your long runs from slow, time-on-your-feet endeavors to aggressive, energy-specific efforts that challenge the physiological systems you'll rely on during race day.
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