Marathon Long Run

The Marathon Long Run


Ahh, the marathon long run. What a worrisome thing for most runners. And for good reason, the long run is such a crucial part of marathon training. I don’t think there’s any other race distance where one single workout plays such a large part in the success or failure of the race. As a result, you’re often left with many questions: How far should I run? Do I run for time or distance? What about pace? What to eat and drink? The list goes on and on.

In this article, I’ll answer these questions for you as I describe my thoughts on the marathon long run and how I utilize long runs for the marathoners I coach. As I like to do, I’m not only going to give you the “how-to” but I’m going to provide you with the rationale for why I think this plan works. This way, you can take the information and incorporate it into your specific training plan.

I will preface this article with a note that these are simply my ideas. Some of them have been widely criticized in forums. I aim to address these concerns but in the end, you have to do what you think works for YOU. And, I would also recommend that you experiment in your training to determine what works for you. With that, here is how I prescribe long runs in the marathon phase. The results have been consistent and positive.


With long runs during a marathon program, you are trying to accomplish two distinct purposes. On the one hand, you are trying to maximize your ability to burn fat and spare your limited muscle carbohydrate (glycogen) stores as well as improving your leg strength and resistance to fatigue (both physical fatigue and mental fatigue). You are also trying to teach your body to better handle lowered blood glucose levels. On the other hand, you are trying to become more economical at your marathon race pace (learning to burn less fuel for a given pace) along with testing out your race equipment and nutritional plan. You also want to give the mind a taste of the focus and determination that will be required in the latter stages of the marathon itself.

Therefore, when I design a marathon training program, I include two distinctly different types of long runs. You’re probably familiar with the first type of long run – the long, steady run. In this run, you simply go out for a steady, easy run and stay out for a long time. The pace isn’t fast and time on your feet is the most important goal, not speed. The second type of long run, however, is new to many runners. In this long run, you start at your normal run pace but you try to average your goal marathon pace for the last 30 to 60 minutes of the run. In most programs, I simply alternate the two types of long runs – one weekend, long, steady distance and the next, a fast finish long run.

I’ll now go through each type of long run in detail so you know exactly how to run each. I will warn you that if you don’t execute the long run correctly, you screw up the program, so listen up.


The key aims of the long, steady distance long run are to increase your ability to burn fat, store more glycogen and to challenge the body and mind to continue running even when fatigued. From physiology, we know that the body uses fats and carbohydrates while running – the portion of each is determined by the pace. Run fast and the reliance shifts to more carbohydrates, less fats. Run slowly and the muscles rely more on fat and less on carbohydrate. Therefore, it is very important that in this type of long run – the long, steady long run, you don’t run fast. You’ll rely more on fats at an easy pace, possibly improving your ability to burn fat. When I say steady or easy or even slowly, I mean a conversational pace. Use my calculator and stay in the “long run” training pace range.

Another aspect of the long, slow run is duration. While running slowly increases fat burning for fuel, another way to really increase fat burning is to run when the carbohydrate stores are lowered. When the carbohydrate stores (muscle glycogen) are lowered, fat burning really goes up since there is little carbohydrate available. We know that the carbohydrate stores are lowered after 90 to 120 minutes of running so you want to do 30-60 minutes of running “after” this to maximize fat burning and to help stimulate the body to store more muscle glycogen for future runs (and races). When running (and racing) for this long, the blood glucose level also lowers. Ingesting carbohydrates (either through a sports drink or energy gels) before and during the run, maintains your blood glucose level. However, as you see below, we may also want to challenge the body to run with a lowered blood glucose level and to adapt to be better at handling a lowered blood glucose level. Therefore, the long, steady runs must last at least two hours and the longer the better and you may want to try to slowly reduce your carbohydrate ingestion before and during this type of long run. Except for a few exceptions, you should try to gradually increase your long run above two hours and I find that long, steady runs of two and a half to three and a half hours are ideal for most competitive marathoners.

Running for this long also helps us accomplish two of the other goals for this type of long run. First, with these runs your legs will get very tired but will become stronger and better able to tolerate running for such long periods. Second, you will experience fatigue and have to be mentally strong to simply keep going, knowing that you are going to continue to feel tired. However, it’s important to remember that feeling tired is what training is about. You receive many benefits in marathon training only after you’re tired. So the goal is to run beyond to the point of being tired so that the body is stimulated to grow stronger and more resistance to tiredness.

Finally, (and this is optional) a great way to ensure that you will deplete your carbohydrate stores on these long, steady runs is to not eat any carbohydrates immediately before or during the run. Any carbohydrates ingested will be used by the body for fuel, and we don’t want this. We want to deny the body carbohydrates in these runs so that the muscles will become better at sparing the carbohydrate stores, more efficient at burning fat and used to running with lowered blood glucose levels. Now, many people think I’m crazy when I say this, but it works. It takes time to get adjusted to it if you have always been carbing up before and during your long runs, but with time and practice you can do it. I will note, however, that it is important to drink water and electrolytes throughout these runs so that you don’t get dehydrated. I also recommend carrying an energy gel with you just in case you run into trouble (like taking a wrong turn, having to run longer than expected and getting a little woozy).

Two words of wisdom here. First, I don’t recommend withholding carbohydrates for runs lasting longer than three and a half hours. And second, withholding carbohydrates is the “icing on the cake” for the long, steady run. The “cake” is the fact that you are running for over two hours. If you’re sent into hypoglycemia by the thought of having no carbohydrates on a long run then by all means, ingest them. You’ll still be stressing the body to adapt to these longer runs.

I cannot stress enough that if you want to adopt this long run strategy that you very gradually wean yourself off of carbohydrates. Your body is likely used to it so I recommend that you continue with your same breakfast and gradually begin to space apart your intake of carbohydrates during the run. For example, if you take an energy gel every 45 minutes, begin to take them every 50 minutes. On the following long run, extend this to 55 minutes. See how your body responds. Then, gradually begin to reduce the amount of breakfast you have before the long run. Over the course of several weeks and months, you will learn that your body has plenty of energy stored in it for long runs and marathons. You just have to retrain it to access these energy stores and not depend on external sources. My experience has been that in most athletes (there are exceptions), the body and mind can be trained to work more efficiently with fuel use in training so that when more fuel is available during the race, you feel like a million bucks!

Another note: I recommend that you do these long, steady runs on a soft, uneven surface like dirt trails. This helps avoid injuries, challenges the accessory muscles and is usually a more enjoyable way to run easily. Take someone along with you as well.

I run my long, slow runs first thing in the morning and have nothing to eat before the run. I tuck a Clif Shot into my pocket on my shorts and hit the trails. I’ll drink water with electrolytes during the run during hotter months but no carbohydrates. I get my 120-180 minutes of running in, then begin the reloading process described in this nutrition article.


The second type of long run is completely different than the long, steady run. The fast finish becomes the focus of this run. You start the workout at your normal easy run pace, increase it slightly in the middle of the run then try to run a very fast pace for the last 30 to 90 minutes of the run. I say ‘fast’ because you will gradually increase to a faster and faster pace so that you finish the run running nearly as fast as you can for the last few miles. I learned this from Gabriele Rosa (arguably the world’s greatest marathon coach). In his program, the last 10 to 30 minutes of the fast finish long runs are like a race. You run as hard as you can and sprint at the finish. It is grueling but very race-specific training. After a few of them, you will see just how effective these are at producing marathoners who can outlast their competitors! Physiologically, you train the body to work more efficiently at marathon pace and mentally, you undergo the extreme fatigue that marathon racers inevitably face during the final few miles.

So, a generic long run for someone who’s goal marathon pace is 7:00 per mile might be that the first 12 miles of a long run will be at 7:30 to 8:00 per mile, then the pace over the last 6 miles will average 7:00 per mile with the last couple of miles at 6:15 to 6:30 pace and the last 400 meters very fast. Believe me, this is a tough run so you will need to get mentally and physically prepared.

The fast finish long run provides an opportunity to practice your marathon routine. Have the same dinner the night before as you plan to have the night before your race. Get hydrated like before the race. Wake up like it’s race day. Do exactly what you plan to do on race day even to the extent of wearing your race gear – shorts, singlet, socks, racing shoes. This is a true “test run” for the marathon. I also recommend that you have someone help you with this workout. Have someone on a bike with you so that you can drink at the same intervals that you will in the race. And, unlike in the long, slow run, do this run (or at minimum the fast part) on the asphalt – just like the race. Also unlike the long, slow run, you want to eat carbs before and during this run. Please note that I just said I DO recommend carbohydrates before and during the fast finish long runs. This point has been overlooked by many runners. In fact, you want to mimic the exact nutrition plan that you will do during the marathon. It’s likely that you’ll have sports drinks every two miles. You may also be carrying energy with you so practice your plan. You’ll be amazed at what you will learn about your planned pre-marathon routine – the things that work and the things that don’t. When marathon day arrives, you’ll be cool and calm because the routine will be second nature to you.

Our general rule when I coached the Discovery USA program was that if you could finish a 14- to 22-mile fast finish long run with the last 8-12 miles at a fast pace and the last 2-3 miles very fast, then you would have no problem accomplishing your goal in the marathon.


While I recommend a two-hour long, steady run virtually year round for most runners, you should not start the fast finish long runs until 8-10 weeks before the marathon. Too many of these workouts and you will peak too soon and be flat by marathon day. And, you only need 2-4 of these long runs before the marathon. So, I’ve found it convenient to simply alternate a long, steady run with a fast finish long run during marathon training. This will put you in good stead for the marathon and keep you from doing too many long, hard runs which can burn you out and make you peak too early. The fast finish long run has to be respected and if taken to extreme will not help but will hurt your marathon. You need to buy into the two types of long runs and do them correctly. Running too fast on the long, steady runs hurts you for the next week’s fast finish long run. Trust me, marathon training is hard enough. Be patient and let these workouts work for you.

To sum up, the marathon long run doesn’t have to be a mystery. Just alternate a weekly 2-3 hour long, steady run with a fast finish long run during the 8-10 weeks before your marathon and you will be amazed at how your body adapts. In the long, steady runs, start at the slow end of your long run pace and run for two to two and a half hours. On the next one, increase the duration by 15 to 30 minutes until 3-4 weeks before the marathon, you are running for two and a half to three and a half hours. (NOTE: I like the longest long run to be no more than 30-45 minutes longer than you plan to race with a maximum duration of four hours.)

In the fast finish long run, start by running just the last three to five miles fast and on each successive fast finish long run, increase the distance of the fast part so that 3-4 weeks before your marathon, you run a 20-22 miler with the last 9-12 miles at a faster and faster pace. (NOTE: I find that jumping into a half-marathon as the last part of your final few fast finish long runs is a great way to get these runs in with the support you will have in the marathon itself.)

If you’re planning your marathon training, I recommend incorporating these two long runs into your program. Good luck!

Post Script:

I originally posted this article in 2005. At the time, it was heresy to not consume carbohydrates during training (though if you talk to the great runners of the 1970s and 1980s, they more often than not had no carbohydrates during long runs.) Some folks took issue (sometimes with much hostility) with the suggestion that limiting carbohydrates was beneficial. At the time I wrote the article, there wasn’t much scientific research on the subject though in the real world, athletes were benefiting from the concept. Over the last few years, I’m happy to report that there are now several well-designed studies in peer-reviewed journals that have confirmed that occasional training without carbohydrate supplementation is very beneficial to performance. As I said in the article, it’s not for everyone but if you have reached a plateau in your marathon performance, long runs without carbohydrates may be the answer for you.

MORE: 5 Proven Marathon Long Runs

Check out Greg McMillan’s Surviving the Marathon Freak Out: A Guide to Running Your Best Marathon


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Written By Greg McMillan
Called “one of the best and smartest distance running coaches in America” by Runner’s World’s Amby Burfoot, Greg McMillan is renowned for his ability to combine the science of endurance performance with the art of real-world coaching. While getting his graduate degree in Exercise Science he created the ever-popular McMillan Running Calculator – called “The Best Running Calculator” by Outside Magazine. A National Champion runner himself, Greg coaches runners from beginners to Boston Qualifiers (15,000+ and counting!) to Olympians.

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