Run Long

In most marathon programs, the long runs are considered the key hard runs. These runs are essential because they allow your body to adapt to the stresses of running the marathon distance. 

Covering the distance isn't the problem--most runners who can cover 10-K in under an hour should be able to walk or run 26.2 miles--but it's a question of how much stress your body can take--and for how long.

By starting with a long run that is only moderately challenging and gradually increasing the length, your body will adapt to running for longer and longer periods while still being able to recover sufficiently for the next hard workout.

While most marathon programs, and runners in general, measure long runs in distance covered (miles or kilometers), I prefer to specify the amount of time spent running. The body doesn't know how far it's running, but it understands effort for a given time. The reason I don't like running a known distance is because it encourages you to race a workout, either against your own standard or someone else. Nothing is more destructive than racing a long run.

Looking at Chart 1, it may seem that the progression is difficult, but if you keep your pace close to that suggested in Chart 2, which is 10:09 per mile (plus or minus 5 to 15 seconds) for our 48-minute 10-K runner, you should be able to manage the long run.

You also may think that the suggested time range for the long run is too slow. Similar to the easy run pace, resist the temptation to go faster. The main value of the long run in the marathon training program is to train your body to be more efficient at burning fat and sparing glycogen stores. 

If you can teach your body to burn fat, rather than depleting glycogen to produce energy, you're less likely to run out of fuel and hit the wall come marathon day. But the faster you go on your long runs, the less likely it is that your body will learn how to burn fat efficiently and the more likely it is that you will hit the wall in the marathon.

While it seems logical that the faster you are able to go on your long runs translates to a faster marathon, it's not true. Trust me on this. The important factor isn't the absolute speed of the run but the relative effort. The effort required to run 6:40 pace for a 32-minute 10-K runner should be similar to the effort required to run 10-minute pace for a 48-minute 10-K runner. The effort is fast enough to be challenging, but it's not too tough. Finally, by staying within the suggested pace for your long run, it will allow adequate recovery for the strength and speed sessions on Tuesdays.

Chart 3: Long-Run Adjustments

Also notice that for most of the runs, I've included a time adjustment that can be found on Chart 3. Our 48-minute runner, for example, can add 30 minutes to the time of the long run on the chart, which in Week 2 would yield a 2:45 long run. (After Week 10, you should not adjust the long runs, as you will be beginning a long taper into the marathon.) You may wonder why 10-K runners with times faster than 40 minutes have a zero adjust factor, and those slower than 44 have a 30-minute adjust factor to their long run. The adjustment is based on what I believe the maximum long run should be. Faster runners, likely to run a sub-3-hour marathon, should not run any longer than 3 hours. Slower runners need to train to be on their feet longer, up to 3 hours, but no longer, to avoid injury. One other important consideration is to make sure water is available at least every 15 to 30 minutes. Plan your long run carefully so it passes water fountains. Or carry a water bottle with you. If you don't want to lug a bottle, stash some water along your loop the day before the long run so you can keep hydrated. Even if it's cool, drink as frequently as possible. You'll need to drink at every aid station in your marathon to maximize your performance, so practice this in training.

Related article:
Benefits of Long Runs

Credits: Text copyright © 1996 by Benji Durden

This article has informational purpose and  isn't a substitute for professional advice.

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