Photo by westpark

A few people had asked me a while back to write about my approach to the LSD or the weekend long run but because I was busy with other things and was already contemplating a blog hiatus, I had let it slip my mind. But after holding several rather lengthy discussions with my brother and a friend on the philosophy of “Running Slower to Run Faster”, I thought it would be best to “kill two birds with one stone” by explaining the physiology behind the long run and why you need to run them at the proper speed (which is usually slower than what most people would imagine) in order to reap the most benefits. Keep in mind that this lesson is geared more toward the beginning marathoner rather than the veterans out there so if anything I speak of here seems common sense or blatantly obvious, please realize that there’s an audience out there for whom this information is counter-intuitive and not so simple to understand. Now that we’re all on the same page, let’s get started.

What is considered a “long run”?
If you’re just starting out and can log just a few miles on your runs, then your long run will be defined by your longest weekly distance run for anything less than a half marathon or 13.1 miles. For those training for a half marathon, the long run will be anything from 10-15 miles. For marathoners, the long run is anything 18 miles and above. For those pursuing ultra distances, the long run might be a marathon or even longer. So as you can see, there is no exact distance which defines a long run. Rather, it must be interpreted both in the context of the individual runner and training goals.

What is the purpose of the “long run”?
Across the board, in virtually every racing distance, whether you are training for a one mile race or a hundred mile race, the backbone of every training program is the weekly long run. If you’re new to running It might surprise you that professionals who race 5Ks or 10Ks frequently spend an hour and a half to two at least once a week on a single run and those who are training for half or full marathons do 2 or 3 times that mean. How does running long help you to run fast? You might ask. Well, the answer is somewhat complex and can be approached on many different levels.

On the practical side, a long run prepares your body to practice and adjust to the constant pounding of pavement. This is especially important to those who are training for long distance races (half or full marathons or longer). Your muscles, joints, ligaments and tendons must be able to withstand the repetitive motion of running for two, three, four hours or more, for you to be successful in your goal distance race. No matter how athletic or fast you may be, if you’ve never practiced going long for a certain time and distance, the body is just not going to be able to hold up for long endurance events on race day.

Another purpose of the long run is for the runner to practice proper fueling and hydration before the big race. For my water needs, I usually like to have 2-3 ounces every 1.5-2 miles depending on race conditions which equates to 1-2 small cups of water or Gatorade at every fluid station. It’s important to figure this out for yourself on practice long runs and develop a solid hydration plan going into your race because the idea of drinking to thirst in a race is just asking for trouble and not going to work. The reason is by the time you realize you’re dehydrated and thirsty in the middle or latter half of the race, your body is already feeling the effects and no matter how much you drink at that point, there’s just no way for the water to be absorbed, diffuse into the bloodstream, and circulate to the overworked muscle fibers fast enough to reverse the negative effects of dehydration. That’s why the best piece of advice I can give to those training to run long distance races is to figure out your fluid needs in different temperatures/conditions, develop a plan, and practice it on a long run. Hydrate early rather than late and do not depend on your own thirst mechanism to guide your fluid intake. Physiologically, the thirst mechanism is the last to kick in in the sequence of events leading to dehydration. By the time you feel is, you are at least 5-10% if not more behind in your intake.

As for fueling, there are many different forms of gels, blocks, and beans that people use for their long runs and races. It’s hard to give specific recommendations for these products because our needs are so individual and what works well for one isn’t going to work well for another. I personally use 1 GU gel at mile 10 when running a half marathon and use 3-4 of them at 10, 16, 20 and sometimes 23 miles when running a full marathon. That plan works well for me both in long runs and races so I stick to it pretty religiously. Again, the key is to figure out what will work for you by trying different nutritional supplements and practicing it on your long runs. If you take care to keep an accurate log of what you try and how you feel during and after your long runs, after a short while you will come to figure out what works best for you and tailor it to your specific goals and needs.

But even beyond promoting muscular adaptation and serving as a venue to practice hydration and fueling, the long run provides the runner a distinct training advantage that is subtle yet powerful and indispensible to athletes in pursuit of performance. This is the reason all training programs, regardless of the distance of the event itself, have them. The important caveat though is that the long run must be done at a specific pace (slow) in order to reap the most performance benefit. Let me attempt an analogy in the next section in order to explain how and why this works.

4 Responses to “Deciphering the Long Slow Distance Run (Part I)”

  1. I am so happy that you are talking about all of this. As a newish (but improving) runner, running slower is something that I’m struggling with (I mean, I am already pretty slow, relatively speaking – to run even slower than that seems counterintuitive). I’m looking forward to the next part…

  2. I was wondering where you’ve gone. I’m on marathon #4, and still need so much help here! Thanks for the info Lam.

  3. great post! I am still trying to figure out long runs, I think I run them too fast sometimes, which negates their benefit it seems like. I also think I got injured a while back because I ran a long run too fast before my body was ready for it. So now I know that I need to run them slow, until my body gets closer to race day and is ready to run it fast. I have heard that running some of the long runs at goal marathon pace for the last 20% of run seems to provide good dividends, I’m assuming that you might talk about that aspect of them in the next post, haha

    And congrats on your 10K PR, I didn’t have a chance to congratulate you, awesome job on your races recently!

  4. Great stuff Lam! And congrats on your awesome 10K PR that I just read about on another blog (Nelly on the Run)…

    I tend to run my long runs too fast (well, too fast for me anyway) and am definitely on board with your Part II. I have a bit of a question about what someone training for a marathon should consider a long run. Your assertion that 18 miles or more seems a bit long. Sure, there will be a few or a bunch of runs in that range or longer, but then what would you consider a 15 mile or 16 mile run? Medium long?

    Perhaps it is the time on one’s feet that is the real arbiter here. If you are speedy then 18 miles will only keep you out there for 2-2.5 hours and may mean that you should add some more distance to get up to and possibly over 3 hours of running. For me 18 miles will take about 2:45 – 3:00 so it’s likely the longest of the long runs I may attempt as I train for my second marathon.

    Your thoughts on training for “time on your feet” rather than distance in the LSD would be much appreciated.



  1. Deciphering the Long Slow Distance Run (Part II) | The Running Laminator - [...] the previous post, we discussed the basics of what a long run is and why it is important, at …
  2. Episode 41 – Live Call In Show | Geeks in Running Shoes - [...] Doug Welch, Dr. Lam (Why you should take the long runs slow), FrenchieGurl, Edmarathon, Reflectiverunr, [...]

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