Essential Efforts to Elevate Endurance, Part 2

Long runs: How many and how far

In Part I of this series, we discussed how hard to do your long runs while training for a marathon. In this column, we will look at how long is far enough, how quickly to increase the distance of your long runs, and how many long runs to do in marathon preparation.

As a marathoner, your objective is to prepare optimally to run 26.2 miles, which includes reaching the starting line (and finish line) healthy. Common sense tells us that there is a tradeoff between running far enough to prepare physiologically for the marathon and remaining injury-free. The probability of injury tends to increase markedly as runs go beyond 20 miles, because when your muscles are highly fatigued, they lose their ability to absorb impact forces, which increases your risk of muscle strains, tendinitis, and even stress fractures. Towards the end of long runs, running technique tends to deteriorate, which can further increase the likelihood of injury. The risk of injury also increases if you do too many long runs, particularly if you have substantially increased the distance of your long runs during your marathon preparation.

How far and how many?

How far your long runs should be, and how many of them you should do, depends on your marathoning experience, injury history and goals for the marathon. The more experienced you are, the more long runs you should be able to handle. On the other hand, the more injuries you have endured, the fewer long runs your body is likely to be able to deal with before breaking down. Depending on your goals, you may be willing to take greater risks during training or prefer to err on the side of caution.

The "long run prescription" table provides guidelines for the number and distance of long runs for marathoners with varying goals and injury histories. Admittedly, every marathoner is an experiment of one, so these recommendations will not work for everyone, but they are appropriate for most marathon runners.