Raise Your Marathon Plateau

Strategies to help you find your breakthrough race

Run on empty

One of the benefits of endurance training-and the long run in particular-is that it teaches the body to adapt to intense effort in the face of depleted energy sources. Shifts from carbohydrate to fat metabolism and the recruitment of muscle fibers in a particular sequence both occur toward the end of a prolonged work bout, especially an intense one. These conditions are difficult to mimic using other workouts. As Pfitzinger says, "The only way to teach your body to use fat 'more effectively' is to increase the volume of training and the duration of long runs."

But another physiological adaptation-an increase in muscles' capacity to store glycogen, the body's storage form of carbohydrate-can be achieved in a number of ways, the long run being only one alternative. "Any time you deplete your glycogen stores, you provide a stimulus for your body to store more glycogen," says Pfitzinger. Because this increases your chances of getting to the finish line without running out of gas, it is therefore of benefit to anyone bent on peak marathon performance.

One way to deplete your glycogen stores is to stop eating. Obviously, this is not a wise choice. However, an occasional, carefully planned reduction in carbohydrate intake combined with certain forms of training can instruct the body to deal with situations of low glycogen availability.

Here's an example: Do an evening or late-afternoon 10- to 12-miler at a moderate pace, eat a low-carbohydrate dinner (fewer than 100 grams of carbohydrate), then get up the next morning and run another 10 to 12 miles. You'll likely feel lead-legged toward the end of the morning session, but "running on fumes" will boost your body's level of the enzymes that facilitate glycogen storage. This in turn results in your muscles having an increased hunger for glycogen and a greater capacity to store it.

It is critical to ingest plenty of carbohydrates following the second run so that hard training may resume within a couple of days. In addition, drink plenty of water before, during and after both runs. This depletion-supercompensation cycle should be attempted infrequently-not more than once every three weeks or so. Intersperse these training sessions with your long runs in such a way that adequate recovery (seven to 10 days) is allowed in between.

A lot to swallow

The purported interplay between nutrition and optimal running performance has resulted in an explosion of gels, supplements and sports drinks. While the runners of the 70s seemed to survive without them, what goes into your system-and when-is an important consideration for runners, and becomes increasingly critical as weekly mileage rises, in order to prevent muscles from becoming glycogen-depleted.