Increasing mileage: the 10% rule?

I recently received an email from a runner who just bought my book Hansons First Marathon and was very concerned that the book didn’t follow the 10% “rule.” I know a lot of coaches, coaching handbooks, and online courses promote 10% increases in weekly mileage. It certainly sounds like a nice idea, but how does it stack up in the research department? Better yet, does it stand up in the practicality standpoint?

Luckily for us, there has been a recent interest in this very topic. In December of 2018, a meta-analysis was published in the International Journal of Sports Physical Therapy. They looked at all articles involving running-related injury as a result of training load, were randomized trials, included ages 18-65, and used runners as subjects. What’s amazing to me is that they began with a database of over 8200 research studies and by the time they were screened for eligibility, only four studies met all the criteria! What this immediately tells us is that this subject has not been looked at with thorough criteria of sound scientific principles. To me, that begs the question then, who settled on 10%? I don’t know the answer to that. It’s just one of those things where somewhere along the lines, somebody made an assessment and it’s just stuck.

So, as far as what did make the criteria, what does the data say? Unfortunately, even with the 4 studies that made the cut, there remain issues. Mainly, the lack of definition of “sudden increase” in training. From one week to the next, from day to day, a rolling average? There wasn’t continuity. However, in one of the four articles, there is some data to extract. All four studies showed that injuries increased with mileage, but failed to define the increase. In the fourth article though, three groups were looked at, 10% increases, 10-29% increases, and 30% increases. The biggest takeaway is that the 30% increases resulted in higher injury rates. The other two groups also resulted in injury rates, but there was no difference in incidence. What this tells us is really two things. The first is that there needs to be more research and clearly defined terms in this area. The second is that when considering mileage as the source of training load increase, that smaller relative increases may not have any more impact on injury rates as does moderate relative increases.

From a practical standpoint, I feel like there a few factors to consider when deciding how much to increase your mileage. The first is where you are currently are with your running. Believe it or not, with a lower mileage runner, we can probably be a little more aggressive, in terms of percentage increase. Let’s take a look at a couple of examples.


10 Miles/week 10% Increase 20% Increase 25% Increases
Week 1 11 12 12.5
Week 2 12.1 14.4 15.63
Week 3 13.31 17.28 18.75
Week 4 14.64 20.74 22.5
Week 5 16.1 24.88 28.13
Week 6 17.71 29.85 35.16
Week 7 19.48 35.83 43.95
Week 8 21.44 43 55


By looking at the chart above, you see that we are using a starting point of 10 miles per week as the starting baseline. In this example, we are using this for a new runner and only looking at running volume. I am excluding other training variables, like intensity, for now. If you start at 10 miles per week and increase your mileage by 10% per week, it would take you two months to build to 20 miles per week. On the flipside, if you believe what research is indicating, and increase by 20% per week, we can knock that time in half. I’ll discuss this more in a second, but let’s discuss the 25% column. You can see at week four, we are almost the same as 20% and just over 20 miles per week. However, after that, you really start increasing the mileage. To double your mileage in 4 weeks is one thing (when starting low), but to the more than double that number again in the next 4 weeks is another issue. To me, when starting at a low number like 10 miles per week, the sweet spot for increasing weekly volume is 20-25% to get to a weekly mileage in the 20-25 miles/week range.

But why do I need to increase that fast?

Won’t I get hurt? Why am I referencing for 4 weeks? Why are 20-25 miles important?

These are all questions that I found myself asking while writing this, and I assume you are asking something similar. So, part of the answers to these involves the research, while the other involves my observations from coaching. Four weeks appears to be a good amount of time to build just your mileage before adding some other source of training load increase. We can do that in four weeks and not significantly increase the risk of developing a running-related injury. I can get a runner to focus on just adding mileage while keeping the intensity low, not take forever to do it, then allow them to get into a training program. I like the 20-25 miles per week because it opens a lot of doors to whatever it is you want to do. Once you get to 20-25 miles per week, you can maintain that, start adding intensity and run a pretty solid 5k within the next 6-8 weeks. If you are marathon training, it allows us to add “slower intensity” and longer run while scaling back the rate at which we increase the volume of training. We are still gaining fitness, but we are adjusting the variables at which we increase.

Now, everything we have talked about so far was to get a runner from initial lower mileage to a solid base level to then start structured training. So, the initial focus was simply more mileage at easier paces, then allowing to shift away from adding mileage as fast but insert more intensity. Once we get to a level of about 30 miles, I don’t think you can continue to add mileage at that 25%. It’s almost a reverse scale. The below chart shows where I think you can be confident in increasing mileage and where I would use caution and where I don’t think it’s a good idea at all.


10% 15% 20% 25% 30%
30 miles 3 Miles 4.5 Miles 6 Miles 7.5 Miles 9 Miles
40 miles 4 Miles 6 Miles 8 Miles 10 Miles 12 Miles
50 miles 5 Miles 7.5 Miles 10 Miles 12.5 Miles 15 Miles
60 miles 6 miles 9 Miles 12 Miles 15 Miles 18 Miles


Think about it this way. At lower mileage, you have a lot more room. You may be able to add another day for a couple of the increases. Then start increasing your long run on the weekend, then a mile to a weekday run, etc. Eventually, you’ll get to a point where you simply can’t just add another day or more mileage to your runs. You’ll also be at a point where you are doing structured workouts and so you’ll be increasing your training load based on that, too. So, by increasing your mileage while doing workouts means you’ll be adding volume, frequency, and intensity. Increase all three by too much at the same time and that is where the body begins to break down.

To summarize, when starting at a low weekly volume, take 4-6 weeks and add volume through easy running at a rate of 15-25% per week. Then back the rate of increasing volume to allow for the addition of intensity, along with gradual increases in daily volume and frequency of runs.

Up until now, all the discussion has been centered around the first time getting to a weekly volume. However, what if you are coming off from planned downtime (post-race)? Or, what if you were training at a lower volume, say for a shorter race, but want to get back up to a higher volume for a marathon segment? Overall, the general theory is the same for my athletes. As long as the volume is something you were able to tolerate previously, then you can certainly be much more aggressive than 10% per week increase.

My general rule of thumb is that the first week of running is about 50% of the desired weekly mileage.

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So if you want to be at a peak of 50 miles per week:

  1. Then I’d run 25 miles that first week.
  2. The second week could see an increase of 25%, to 31.25 miles.
  3. The third week could be a 20% increase, to 37.5 miles per week.
  4. Then the 4th week could a 10% increase to 41.25miles. At this point, you are about 80% of the peak mileage and healthy place to start introducing workouts.

That’s a summary for what I do post-marathon, but if you are coming off a shorter race like a 5k or 10k, you can probably get away with a 2-3 week buildup and then start workouts during the 3rd or 4th week back. Granted, this is all dependent on the fact that you are healthy or the source of the problem has been addressed.

To me, the biggest takeaways are that there’s not a lot of research to show that 10% should be a hard and fast rule when increasing your mileage. Like a lot of items in training, it’s dependent on your factors. It’s also more about a relative percentage that makes the most sense. A 30% increase at 10 miles per week is a lot more reasonable than a 30% increase at 50 miles per week. Lastly, I feel like we have had much more success when focusing on mileage first at low intensities before slowing the rate of volume increase to accommodate more intensity. Granted, if you know you are injury prone, maybe focus on become more resilient before trying to make big jumps, or explore common themes when you became injured- it may not be the mileage at all. Experiment with what you can tolerate, but don’t think you have to be suck in the 10% rule. 10-29% appears to be the same in risk for developing running related injuries. Keep that in mind the next time you are designing your plan.

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Increasing Training Mileage: How to and when to stop!


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Mileage is always a big topic of discussion with runners, almost a badge of honor for some runners. For newer runners, the questions usually revolve around increasing mileage safely but quickly (sometimes just quickly) while with more advanced runners, the questions might be centered more around how much mileage is enough. What I’d like to do is offer up some thoughts on common “rules” and give you some ideas to think about when you start looking at your own training volume.

The most popular method of increasing mileage, by far, is the 10% rule

General Theory

The most popular method of increasing mileage, by far, is the 10% rule. A quick Google search on “increasing running mileage” will show you numerous articles. This has come under some criticism- just read those above mentioned articles. It certainly is a pretty conservative approach, especially with newbies and general low mileage runners. For instance, if you run 10 miles your first week of running, then this rule says that the most you can add is 1 mile. The practicality of that isn’t necessarily high. You might have a variance of 2-3 miles without even trying.

Another theory comes from the ever famous Daniels Running Formula which Dr Daniels writes about adding no more than one mile per run per week. For instance, if you run 4 times per week, then add no more than 4 miles the next week. This proposal is seemingly scalable, as many competitive runners will run 10 plus runs in a week and that would probably be about a 10% increase in mileage. So, for lower mirage runners, the amount you can increase may be more like 15-20%. This makes sense because adding even a small amount of total weekly mileage in low volume runners will tend to be higher than the very conservative 10% rule.

What’s best way to approach? Well, for lower mileage runners the 10% rule is probably to conservative. To be honest, at that rate of increase, you’ll spend all summer just trying to get to a decent weekly volume. For higher mileage runners, there’s probably not going to be much difference between the two philosophies. And, for these folks, your concerns probably lie in other areas- which we will discuss later. The following are things that I would consider when deciding on your approach.  

Things to consider when discussing volume/mileage

  1. Maximize your current level before making a jump. It takes 4-6 weeks for the body to adjust to a new training stress, so don’t jump to another training stress until you’ve gained what you can out of the current training stress. If you can still adapt at a lower training level, then why not? Otherwise, you have the risk of jumping up too much too quickly and getting injured.

One of the most common issues I see with beginning runners or runners trying to make a big jump in training is that they were feeling great and then, BOOM! They got a tendonitis or a stress fracture. What we tend to neglect is that our cardiorespiratory fitness can increase quite rapidly, within a couple weeks. However, things like bone and tendon take much longer to catch up. So, if we jump up too much, despite the increase in fitness, we end up sidelined. That is why I say to not really jump up a little bit every week, rather increase a moderate amount every 4ish weeks and then stay there. It won’t be as slow of a buildup as the 10% rule, but not so fast that the body can’t adjust. Running more mileage is only good if you can do it consistently!

Increasing Training Mileage: How to and when to stop!

Increasing Training Mileage: How to and when to stop!

2.  Focus on endurance before intensity: In general fitness we look at the acronym FITT which represents frequency of exercise, intensity of exercise, amount of time exercising, and type of exercise.  When we begin increasing mileage, we are potentially adjusting all four of these variables. If we add a day to our routine, we automatically are adding more time that we are engaging in a certain type of exercise. As you can see, the odd man out here is intensity. If you try to increase or change all the variables at once, something is going to have to give.

There are times where you will be increasing mileage and doing workouts at the same time. The key here is that you aren’t making major jumps in training when trying to do both. Ultimately this comes back to thoughts on our philosophy where you train at a moderate level of mileage most of the time, which minimizes big swings in training stress for extended periods of time. I believe it also goes back appropriate paces. If we start cheating paces down because we feel good, we ultimately run ourselves down and become, at the least, overtrained, but at the most, sick and injured. Lastly, it makes it crucial to not get caught up in cycle after cycle of training for the same distance. While the traditional base period may be falling out of favor, it’s a perfect time to give yourself a block of 6-8 weeks to focus solely on building to new mileage. By making some type of compromise I believe the road to your eventual goal will ultimately shorten.

  1. Use cross training as a transition, not a replacement. Many people look at the training plans in Hansons Marathon Method and Hansons Half Marathon Method and view us as anti cross training. This is simply not the case, rather I truly feel that in the case of increasing mileage, cross training should be supplementary and not a replacement for running.

For example, let’s say you are following a program that has you running three days per week, what are you doing the other four days? Your first step should be to make sure you are cross training at least a few of the other days. From there, you start replacing a cross training day with a running day (we’ll talk about days over adding to current runs later).

Personally, if you are using our training philosophy, I’d like to see you build to at least five running days per week. If you are more of a 5k to 10k runner, you can probably do alright with 3-5 days, but once you start getting to that half marathon distance and up, you really should try to build up to more than 5 days of running per week. I have gotten plenty of backlash over that, which is fine, but this isn’t the place for an argument. I would just encourage you to look at our posts on philosophy and training components to see where our theory comes from. I will just say, that if you are low mileage, allow yourself even more time to prepare for a race so that you can still get all the work you’ll need to in order to be ready.

  1. Do I add to my current runs or add days to my week? This is a question we will get a lot. My basic thought is that a run should be at least 30 minutes in length. So for most people we work with, that’s a 3-5 mile run. Adding about 5 miles per week is pretty common under the systems we have talked about, but the duration of that 5 miles is what will be the differential. So, if you are running about 10 minute pace, you might be better off adding a 3 mile run and then 1-2 miles onto another run or across two runs. Or, maybe you aren’t currently at 30 minute runs? Spread the mileage across the week to get those runs up to that 30 minute mark. Also, when I am adding mileage, I am talking about adding easy mileage before adding mileage to workouts and long runs. Using this, I’d follow the process until getting to the desired days per week you want to run. After that, you can start adjusting other variables within your harder efforts.
  1. Give yourself enough time at a training level. We touched on this a little bit, but allowing yourself adequate time to fully adjust to a new training level. Now, if you are following the 10% rule, then you can go a few weeks in a row of increasing your mileage, but on that third week, you may want to consider staying put for a couple weeks before making another jump.

With really small jumps it’s probably OK to make continual jumps- to a point. What I personally don’t like is that you now have to guess when a you’ve made a big enough jump. That’s why I like to keep it clean and clear cut- make a moderate jump, then stay put. This allows your body to completely adjust to the mileage. As we mentioned, your cardiovascular system will adapt pretty quick and you’ll have the urge to make another jump, but I urge you to fight that urge if you are venturing into new mileage territory. Give your bones, tendons, and musculature plenty of time to adapt to the increased stress.

Non-beginner situations: so far, we  have really just discussed ideas for runners who are trying to get their mileage up to a point where the need to be, in order to compete at the level they want. There are other scenarios where we discuss building back to a previous level and most of that is when we are coming back from being sick or injured. We have discussed that in pretty decent detail in our Dealing with Injury and Illness video, so I won’t go back into it now. For me there are two scenarios where we can discuss mileage in a setting where the goal isn’t to establsh a higher training baseline.

Coming back from planned downtime. This is pretty common- especially if you use our training. For the marathon, we prescribe pretty lengthy downtimes, usually 10 days to 2 weeks. For shorter races, generally, you can expect less down time depending on the runners situation. Here’s how I would handle building back:

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For 5-7 days of planned downtime (still healthy)

  • First week: 50-60% of peak mileage, spread over several days, but giving yourself 1-2 off days during the week. All easy mileage.
  • Second week: 70-80% of peak mileage, but keeping it easy, with 1 (maybe 2) off days and a longer run.
  • 3rd week: 80-90% of peak goal mileage with a long run and one light workout- usually a progression run (or cutdown run, depending on your terminology)
  • 4th week: 90% of peak goal mileage and a light track workout (8-12×400’s for example) and a long run.
  • 5th week: resume normal training.

For 10-14 days of planned downtime (still healthy)

  • First week: Every other day of 30-45 minutes easy running
  • 2nd week: Five days of 45-60 minutes easy running
  • 3rd week: 5-7 days of running, making sure at 60-70% of average mileage, including a longer run
  • 4th week: 5-7 days of easy running, totaling 80% of usual volume including a longer run and either light 400’s on the track or a cutdown, followed by a weekend longer run
  • 5th week: Same as the 4th week, just alternating what workout I did the previous week. Volume may be 80-90% of goal volume
  • 6th week: Begin training for next event.

How much is enough mileage? This isn’t something I see discussed a ton, but it is an important topic. A couple of recent examples on our Facebook group and local runners that got me thinking more about this.

First, let’s preface this with a case studies of a runner who has followed a common path that started with simply following the Advanced Marathon Plan in the book. Our first athlete, Dave, came to me when he was in his early 40’s. He ran in high school but hadn’t run in decades. He followed the basic plan and ran his first marathon. If I recall correctly, he was right around 3 hours, a little north of three. From there, we’ve been gradually increasing his mileage and tweaking his training. Now, a few years later, David averages about 75 miles per week when training for a marathon and run 2:45 in the marathon. In a perfect world, David would run more, but he’s a crazy busy business man, husband, and father of teenagers. Every time we try to do more, David breaks down or gets sick. His schedule just doesn’t allow it. Instead, we try to focus more on details like strides, stretching, some strength, and diet. We’ve maxed out the mileage and turned towards the other facets of training.

Now, there’s another runner who is a local guy. I don’t coach him, but have watched him train for a number of years through our local group runs and workouts. He’s a couple years older and trains a lot more than David. I know this runner will hit 100 mile weeks on a regular basis during the marathon training blocks. I watch this runner and it almost hurts me. He is hunched over with a very weak core and his stride is very short and quick with no hip extension. I’m not trying to pick on this runner, but this is what got me thinking. In his particular case, the 100 mile weeks aren’t improving his ability anymore. Personally, what I would do is back off the mileage, take a block of time and focus on strengthening his core and improve his form through fixing muscle imbalances.

What’s the point of this comparison?

It’s really to show you that early on, we will improve just by running more mileage. However, eventually we will get to a point where more mileage isn’t going to yield results (the idea of diminishing returns). Now, don’t take this as contraindication to running moderate to high mileage, rather your body, your work and your family schedule will reach a breaking point. You probably can’t do much about the last two, but you can work on body weaknesses.

With that said, there is no perfect answer for mileage. In the books we lay out some guidelines for runners to gauge their ability to what their level of expertise is.

Beginner Competitive Elite
5k 20-30 40-50 90+
Marathon 40-50 60-70 110+

There’s a couple ways to  look at this. The first being that if you want to run to compete in age groups, win local races, etc, then you’ll probably have to run more than 30 miles per week. You can use it as a guide to build to. On the other hand if you are cranking out a ton of mileage and aren’t performing at the level you’d like to, then maybe it’s time to reevaluate your approach. Obviously this is an extremely simplified way to look at things, but at least can be a starting point for you. It also goes back to what we discussed earlier- maximize where you are at first before making a big jump. This can include those supplemental components, as well.

So there you have it, some general thoughts on increasing your mileage safely, but not taking forever to get to a desired weekly volume. Hopefully, this will guide you as you think about where you are and where you want to take your running.

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