The Long Run

So it's been a little bit since I posted my last blog about training plans.  Overall, I received good feedback except where I talked about the long run. 

Before I get into the complaints, let's list some of the main points that I made in that last blog concerning the long run.

• Your long run should only make up between 25-35% of your entire weeks worth of miles.  So if you ran a total of 20 miles this week, the maximum number of miles you should run in a single run should be between 5-7 miles. 
• If you run only 3 days a week, then every run is a "long run".
• Don't just increase your long run week after week.  You should increase the miles in all your other runs during the week. 
• Do not cut your long run into 2 shorter runs in the day.

Then there is the additional restriction that Dr. Jack Daniels has for the long run to be limited to 2.5 hours.

So according to Jack Daniels, unless you can run a 20 mile training long run at a 7:30 pace (8 mph), then you shouldn't be running a 20 mile long run.  Because it would take you longer than 2 and a half hours to complete that long run and increase your risk to injury. 

Now even in my blog I admitted that some of my long runs near peak marathon training were 3 hours and maybe 3:15:00'ish.  "But I don't make a habit out of it."

So when do you break these "rules" and when don't you?

Here's some feedback from my training plan blog:

• "... My issue is that if I only get to a total distance of 23-24 km for my long run because that represents 3 hrs of running, then that is nowhere near the time or distance I will require to run the marathon, and how on Earth will I be able to run for another 2 hours on race day!"

• "The 20 mile long run is here to stay. The 2.5 hour limit is not realistic for the non-elite runner. While Jack makes some good points, I think his solution is unrealistically restrictive for most of us."

• "Maybe instead of saying, 'An elite runner will only run 2.5 hours on a long run, so an average runner should only run 2.5 hours,' we should say, 'An elite runner will run X% of the time it takes him to complete a marathon on a long run, so an average runner should run X% of the time it will take to run the marathon.'  At that point, we could be right back to the 20 mile long run, assuming only that the average runner's ratio of long run pace to marathon pace is similar to the same ratio for an elite runner."

• " I am doing my first marathon in July, and I have one of those 18 week plans @Stoshew71 critiqued! I have extended the plan out to 27 weeks to give myself a bit more time to build mileage, but there is no way I will have time to build the mileage to support a 32km long run if I try to use the 25-30% of weekly mileage rule.  And I will also be violating the 2 1/2 hr to 3 hr rule almost every week until my marathon, because I am running slowly (7 1/2 to 8 mins/km), and hence covering the distances slowly. My issue is that if I only get to a total distance of 23-24 km for my long run because that represents 3 hrs of running, then that is nowhere near the time or distance I will require to run the marathon, and how on Earth will I be able to run for another 2 hours on race day!"

• "In the past, when I was running only 3 times per week, I used to have weeks like 5km + 7km during the week, with a 10km long run on the weekends, i.e. making up more than 45% of the weekly distance. But with three runs per week, the only way to have the long run at 33% would be to run the same distance all the time - that just didn't make any sense to me. It just doesn't work until you run longer distances and more often.

• "There are reasonable arguments for the '25/33%' rule. But on the other hand, I was chatting to a guy at the running store (another customer) a while ago, who was vehemently against adding more runs for the sole purpose of 'getting the percentage down'. His argument was that if I went from three midweek runs to, let's say, five 10km runs, that wouldn't prepare me better for a 20km run on the weekend. Sure, the long run would only be 30% of the week that way, but it would still be twice as long as my other runs, and I'd have only one non-running day and therefore less time to recover. His advice was instead to try to have one 'medium long' run in the middle of the week, which should be 75% of the long run. I found his arguments quite convincing, which is how I ended up with weeks like '8/13/4 + 17'"

• "I think where most people would have a problem is doing those 4-5 hour training runs to 'get the miles in' without the base during the week; if the midweek runs are just 3 to 4 miles and then someone tries to do 16-20 on the weekend, that's where you really set yourself up for a big fall. I experienced this in my first training cycle; my midweek runs were 3-4 miles, with ony 6-7 miler, then I was doing 15, 16, 18 miles on a Sunday... no wonder I spent half my training weeks toward the end babying injuries!"

• "Overall, I at least sort of understand why Jack Daniels cuts off at 2.5 hours. But elites can run 26 miles in less than that -- often significantly for elite men. To cut off an average runner's training at 2.5 hours seems a bit premature when they may be running for 2 or 3 hours longer on race day. I still stand by the 3-3.5 hour rule; I don't think someone can run a marathon very well with only a 16 mile training run under their belt -- or even less mileage depending on speed. Can they finish? Sure. But will it be a good experience? I would be skeptical. Plus, for many average runners, 2.5 hours worth of running is not far enough to really address hydration and fuel issues and come up with a strategy, especially for those runners for whom a marathon WOULD take 4.5-6 hours. Example: A friend of mine did her first 15 miler last weekend, which clocked in just shy of 2:20. That's still a good pace (~9:10), but she barely had to tap into hydration and fuel (she only took 2 gels). And the thought of running 10 more is still very daunting. A half hour or 45 minutes more (up to 19-20 miles) would not only boost confidence but prepare her better and allow her to create a race strategy, and if played right, she could still recover well even if her mileage is peaking at 45 mpw."

• "My take on the subject is, there's a huge illusion of accuracy. Much of what we think we know is a compilation of what worked out well for elites. We don't really know how to extend that to average runners. I think there's a lot more play in what will work than most training systems allow, and I think that what the runner's goals are is under-emphasized. In particular, I think training plans have too much speed work for people whose only goal is to finish. If speed isn't important, why introduce an additional injury risk from running hard in training?

• "I also recall reading about a guy who does a marathon every week, and has for years. Now he's old, and about the only running he does is on race day. He's made it work, for himself"

• "Regarding the long run and a limit of 2.5 hours due to injury prevention...I've read about doing a simulated 20 mile run by running long (but shorter than 20 miles) two days back to back but what about using cross training? Say biking for an hour or more followed by 2.5 hours of running? Would there be benefit to that"

So before I get into the valuable comments above, let me introduce some concepts about the long run itself.


The main purpose of the long run is to train your body to rely more on stored fat for energy than on carbohydrates. When you exercise, your body uses both the stored carbohydrates (glycogen in muscle cells and liver) as well as stored fat (triglyceride in the adipose cell).  But the body initially prefers carbohydrates since the process to use glucose to manufacture ATP is much simpler than using fat.  If you are a sedentary person, over time atrophy sets in and your body's ability to use stored fat for energy decreases.  The same holds true for your overall cardiovascular capabilities.  To add to matters, the same sedentary person is constantly eating carbohydrates over the course of the day, so the body is constantly relying more on carbs for fuel and is constantly storing the excess as fat. So fat is being created at a much more faster rate then it is being burned.  Thus leads to weight gain and other problems.

The long run is more than just the longest run you run in the week.  To me, in order to qualify as a 'long run', you must be running within your aerobic level for at least 90 minutes.  Why your aerobic level and why 90 minutes you ask?  First off, if you run beyond your aerobic level (easy pace or conversational pace) then you are forcing your body to burn glucose.  When you run anaerobically, that means your muscles do not have enough oxygen to use fat for fuel.  Only glucose can be used to produce ATP when not enough oxygen is present in the muscle cells.  So it is very important to run your long run at a nice easy pace to promote fat burning.  The second reason, as already mentioned, the body much prefers glucose over fat for energy conversion because it is a much simplier process.  But your body has only a limited amount of stored carbohydrates.  When the glycogen stores begins to exhaust, the body automatically makes a conversion to release enzymes that will speed up the burning of fat for energy use. Usually this conversion requires 60-90 minutes of running.  Runs shorter than 60-90 minutes is usually burning carbs at a higher ratio than fat. Running for at least 90 minutes definitely increases the ratio of fat burning over glucose burning.  Keep in mind that ratios switch between carb to fat burning.  The body just doesn't stop burning carbs and begins burning fat.  But the longer you run (as long as you don't incur extreme oxygen debt and remain in the aerobic zone), the body will burn more fat than it will burn carbs. 

However, if you have been relatively sedentary and are not used to exercising for 90 minutes straight, because of atrophy, the body may have "forgotten" how to make enough enzymes that will sustain the level of energy required.  Your cardiovascular system may also have deteriorated enough to start incurring oxygen debt much sooner than necessary to make the conversion.  So there is a training period that needs to be overcome and in the mean time, you will feel very sluggish during the late stages of your long run.  But make the commitment to continue this week after week.  Your body will be stressed and will begin to improve your cardiovascular system and will begin to produce the required enzymes in higher quantities.  The more you stress this function over and over again by increasing the time you run a long run, the more efficient your body will be to use fat as a means to convert energy. 

This is very important when you run half marathons and vital for full marathons.  The body only has a certain amount of carbohydrates that you can store.  And refueling techniques are limited in what they can provide.  That means if you ran for more than 2 hours, you will begin to completely exhaust all your glycogen stores, and eating Gu or jelly beans or drinking Gatorade will not help as much as you like.  That is because your body can only process so little of what you eat in the time it needs to use it to help you run.  While exercising, your body can roughly digest and absorb at most 150 calories per hour while it is burning around 700 calories per hour and possibly more depending on intensity.  So the math does not add up.  You cannot replace what you spent by eating or drinking.  The secret to running 3-5 hour marathons is by increasing your body's ability to use fat for energy more than it does on carbohydrates.  That is the main purpose of the long run.  To stimulate the body to use fat for energy.  There are also tricks to enhance the long run.  Like running in a fasted state.  That means you have not eaten anything long before you run so that your blood glucose levels are no longer elevated (and possibly have already exhausted liver glycogen stores).  For example, I will wake up early in the morning and have no breakfast (minus a mug of coffee) before my long run. So what you need to run immediately comes from stored fuel and not from what you recently ate.  The other thing is to limit or not refuel while you run.  Drinking water and electrolytes during the long run will not break the fast, so it will not hamper this strategy.  There is a level of diminishing returns to running in a fasted state so it is wise not to always practice this strategy.  You also can use the long run to practice taking in fuel while you run as well as experimenting with different types of fuel to make sure they agree with your body.  So some long runs can be done fasted, while other long runs are done with say preworkout breakfast and on the run refueling.

But there are quite a few other benefits to the long run as well.  Yes, you build strength the longer you run. But the longer you run, the more time you need to recover. You can do something similar by running more miles during the entire course of the week or even run again later on in the day. How much of a rest do you need when you run a certain distance? That is something you have to figure out on your own since this effects everyone differently.

Here is my theory why to cut it off early (whether it is 2.5 hours, 3 hours, or 3.5 hours...). So as you run, in the beginning you will be burning more carbs than fats. But eventually your body will rely more on fat than carbs (especially if you are running at an easy pace). How fast you make that transition and to what ratios? That is the main purpose of long run training. To improve this function. As you keep running and running, even though your body begins to rely more and more on fat, you will still burn a certain percentage of carbs, and the more intense you run, the more of a percentage it will be in carbs. - btw more intense does not necessarily mean faster.  Fighting to maintain the same pace could also mean more intense. Eventually, you will exhaust your carb stores (or comes close to it) and the body and mind begins to fight back. At this point, it is no longer a physiological training exercise, but more of a mental thing. Your slow twitch muscles would have weakened a long time ago causing you to engage your medium twitch and then your fast twitch muscles. But eventually those get exhausted too. The faster twitch muscles exhaust at a much faster rate than the slow twitch muscle fibers. So your pace will drop unless you run with more intensity. As you continue to run, you begin to cause more and more trauma to your muscle cells which require more time to recover from. Truly, at this point it becomes solely a mind game and not a physiological thing. Now is there a benefit in this area that Daniels overlook? I believe so. You are pushing your mind to force your body to continue. But there is a cost to this as well as a benefit. That is what you have to decide when you go beyond whatever suggested limit.

So the point I am making is by running your long run longer than 2.5 hours, 3 hours, 3.5 hours...  you are no longer stimulating the body to improve.  You are actually forcing muscle damage.  The more damage you do to the muscle, the more time it requires to recover.

So in order for me to race a marathon, I will require about 2-3 weeks of tapering just to recover from my training so that my body is at it's highest state of health and fitness to do my best performance on race day.  After I am done with my race, my body will require about 2-3 weeks of reverse tapering to recover from the damage caused by the race.  So if it takes this long to prepare and recover from a race, why would I want to simulate that very same action within my training runs?  Do I really want to run such a brutal long run on a Saturday morning (after already training hard in the week) so that when Monday morning comes along, I cannot perform a good workout?  This is the main reason you limit what you do in your long run.  Your success on race day will not be as a result of one single 20 or 22 mile long run, but from all the weeks and weeks of good training all working together to improve your body holistically.

Now while I run 20 milers and even a couple 22 milers before a marathon race (against the advise of the 3 hour limit), I also know that my weekly mileage means more than hitting that 22 miler. When I ran my first 20 miler, I really started to feel it around mile 18. My pace really dropped. My last 2 miles were 2-3 minutes slower than the first 18. I questioned, if this is what happens when I hit 20, how the heck am I going to hit 26.2? I had folks reminding me that at the same time I ran this 20 miler, I also had a full week of runs. When I do it for real, I will have a long taper and carb load, and that will take me over the edge. And they were right. When you do your long training run, you have to realize that you are doing it already with tired legs (from your other runs during the week). So you don't need to go as far to be in marathon shape. And you can do it with less recovery time.

Now do I run 3 hour long runs? Look at my strava entries and you will see quite a few of them. Some even 3:15 and 3:30. So yes, even I break Daniels rule. But I try to not do it very often. I also believe that while there may not be any physiological benefit for going beyond 2.5 or 3 hours, there is definitely a mental benefit. There is a huge mental confidence builder for the first time marathon experience. I was pumped up when I completed my very first 20 miler training run ever which took me over 3 hours. So I agree there is a benefit, even if only mental.


So when do you break a rule and when don't you break a rule?  The answer relies in 2 things.  1) The more you understand the science to running and training and the purposes of why you do a certain things, the more you understand the purpose of these rules.  2) The more you practice or break these rules, the more you understand how your body reacts.  For example, if you run a 3 hour long run on Saturday but find out that your Monday morning run was cut short because you just didn't have it in you?  Then you know that running another 3 hour long run next Saturday is probably not a very smart move.  But if you find out that your 3 hour long run had no effect on your Monday morning run, then you will be more inclined to do more 3 hour long runs and maybe even attempt a 3:15:00 long run. 

So what about the old guy that runs marathons every week?  I know a friend that ran a couple of marathon races with this guy.  The old guy isn't really "racing them".  He's just running them at a slow enough pace so that he can run his next "race" the following week.  He is a 'back of the pack' runner.  He also just didn't wake up one morning and wonder, "what would happen if I ran a marathon every week for a full year after never run a marathon ever in my life?".  I am sure experience and stamina plays a big part in this.

Can you train for a marathon or half marathon on running just 3 or 4 times a week?  Depends on the runner.  It is not a very good strategy in my opinion, but doing so will present many challenges that you will need to face and answer.

Another question that was asked, if I run 2 'long runs' during the week, do both long runs added together have to be 25-35%?  The answer is no.  You take the longest single run of the week and make the comparison. 

How does cross training play into this?  I think cross training is valuable, but it doesn't replace running.  In my opinion, there is a certain amount of running that will be required in order for you to meet your goals.  Short changing your weekly mileage in favor of cross training will not do you any justice.

What about breaking your long run into 2 smaller runs?  I mentioned in my training plan blog that there is a purpose behind the long run.  I explained the purposes of the long run above.  To put it all into prospective...  If you have scheduled a long run that would take you 2 hours to perform, but decide to break it up into 2 1-hour shorter runs, then what good will that do you?  There is a good chance that during both of those shorter runs, you will be at a higher carb-burn ratio than a fat-burn ratio.  So you be short changing the main purpose of the long run.  Especially in between your 2 shorter runs, you had time to eat something and your body began to replenish those glycogen stores.  Each of those shorter runs will begin with a full glycogen store.  This is not the same thing.  Your muscle fibers will have also recovered.  So you don't get to practice as much the muscle fiber recruitment ladder.  And lastly, while you main do a good job of focusing on staying in the aerobic zone for both shorter runs, you end up missing out on enhancing oxygen debt through distance. For each shorter run, you will initially be starting at fully recovered oxygen levels due to EPOC in between runs. That means, the longer you run, even at a comfortable conversational pace, eventually your body will still incur some level of oxygen debt and lactate buildup.  All of this is very important part of your training. EPOC (excess post-workout oxygen consumption) is a way your body recovers from oxygen debt incurred during a workout.  Even if you took a short 20-30 minute break in the middle of your long run, you lose a major training stimulus that results when lactate is produced in the body.  Distance induced lactate is much different than pace induced lactate.  So the benefits of the long run are different than say 2 tempo runs.

Again, training plans are more as guides than doctrine.  That goes for all the rules as well.  They are guides.  They should be used to help you train smarter.  But only you know what your body can really do.  You need to tailor your workouts and training according to what works for your body and personality.  You also need to tailor your training plan to what works in your life.  A married person with kids and a full time job will have far less time to train than a professional runner that actually trains for a living.