marathon training week 12

This is the first of my 12-part marathon training series that will coach you through your marathon build up, week by week.These guidelines will work for the majority of runners, although runners at the extreme ends of the spectrum will need to modify.

Most marathoners need about 12-16 weeks of marathon-specific training to get ready to race the marathon well. That does not mean it’s a good idea to start from zero running and hope to run a marathon 3-4 months later! Yes, there are people that do that, of course, but those are the wildly optimistic or genetically gifted (or both). And they usually regret it.

Here’s what you need to do to get ready before you begin marathon training.

If you are a newer runner or someone who just needs a little gentler entry into marathon training, you’ll want to start the marathon build at 16 weeks away from your race. This allows you to build your long runs and weekly mileage a little more slowly.

If that’s the case for you, you can apply everything I’m talking about in Marathon Training Week 12 to the preceeding 4 weeks and gradually build up to this point.

I like to toggle between easier long runs and harder combo long runs every other week.  This allows you to keep your mileage strong, but also give you an extra challenge every other week.  To make things easy to remember, even weeks are easier, odd weeks are harder.

Week 12 is an easier week.

Marathon Training Week 12: Mileage and Frequency

When you are twelve weeks away from your race, your mileage should be around 30 miles or 48 kilometers a week, or more. Some runners will be okay with less, especially if they do another form of aerobic exercise, but this is a solid base.

Thirty miles spread over 3 days a week is a challenging ten miles a day. Of course, we don’t want to evenly spread out the mileage since you will be running long one day a week, but it’s tough plan, especially for slower runners. This is why I recommend most marathoners build up to 4 days (or more) of running a week if possible.

Marathon Training Week 11: Schedule Examples

If you are running 4 days a week, here’s what the mileage could look like:

  • Easy with strides: 5 miles (8k)
  • Speed: 7 miles (11k)
  • Easy run: 6 miles (10k)
  • Long run: 12 miles (19k)
  • TOTAL: 30 miles (48k)

If you are running 5 days a week, it could look like this:

  • Easy with strides: 4 miles (6k)
  • Speed: 7 miles (11k)
  • Easy run: 4 miles (6k)
  • Tempo run 2-3 days before long run: 6 miles. (10k)
  • Long run: 12 miles (19k)
  • TOTAL: 33 miles (52k)

If you are running 6 days a week, it could look like this:

  • Easy with strides: 4 miles (6k)
  • Speed: 7 miles (11k)
  • Easy run: 4 miles (6k)
  • Tempo run: 6 miles (10k)
  • Easy run: 6 miles. (10k)
  • Long run: 12 miles (19k)
  • TOTAL: 39 miles (62k)

I don’t recommend running 7 days a week in marathon training unless you are very advanced, very strong, and very injury proof.  It usually causes more harm than good because a rest day is critical to building and repair.

Marathon Training Week 12: Long Run

Your long run this week is all easy pace to build your aerobic capacity. It should be around 12-14 miles, depending on ability and experience. You should be running so gently that you can sing along with your music or argue with your podcast!

Learn more about why running easy is so critical here.

This week, and every long run to come, you’ll want to start practicing your fueling and hydration. Even though these training runs are much shorter than your race, fuel as if you are running 26.2 miles (42.2k) every long run.

Experiment with gels, sports drinks, chews and other kinds of fuel to see what sits best in your stomach. Just like your legs, the stomach can be trained, but it takes lots of practice.

General recommendations are 30-90g of carbohydrate per hour, which works out to be 120-360 calories. Yes, this is A LOT! Bigger runners need more and smaller runners need less, but the more you can tolerate, the happier your brain and your muscles will be.

marathon training week 12

Marathon Training Week 12: Speed Work

In the early weeks of your cycle, your speed days should be focused on shorter intervals with more rest.  This allows you to work on that high-end speed that will help make all your paces easier.  As the weeks go on, your speed days should start to shift to longer intervals that work on your stamina at those faster paces.

Try to do all your short speedwork on a track or other flat course, even if you are training for a hilly race. This allows you to run your very fastest, which translates to better running at all paces.

After a mile or two warm up, stop, stretch, do some running drills, use the bathroom, and get a drink. When you are ready to run the speed portion, run hard, but never all-out. The goal is to complete all the intervals at roughly the same pace, getting full recovery in between, and have just enough left over that you could run another interval at the same pace (but you wouldn’t want to!).

Then cool down for a mile or two.

For marathoners running a second speed day, a basic tempo run at about a 6-7/10 effort level is great for building stamina.

Strength, Drills, Mobility

If you don’t already have a solid strength training habit, now is the time to start. Marathoners do not need to become bodybuilders, but adding strength is essential to faster and easier running and helps lessen the risk of injury.

Most marathoners do well with two 15-minute strength sessions and one 20-30 minute session per week.

Here are more details on exactly how to plan your strength work.

Drills and mobility work are often overlooked but they can help you boost your running economy and efficiency. I like to include them in my warm up routine so I don’t forget!

Sleep, Recovery, and Rest

Sleep is the most effective performance enhancer there is, so be sure that you are getting plenty during your marathon build.

Recovery is allowing enough downtime between hard runs and workouts so that you are fresh enough to run well again. For some people, a slow jog works well, for others, walking is a better way to recover. Staying lightly active is usually more effective than full rest days with zero activity.

Full rest days are important and most runners need at least one day off a week, both physically and mentally. I still encourage runners to get outside for a walk or to do some very light activity on a rest day if possible.

Nutrition to Support Your Running

When your goal is to build endurance and muscle, you absolutely must fuel with enough calories before, during, and after the run. Yes, fat loss is possible while training for a marathon, but the goal of fat loss requires a completely different strategy than marathon training.

I’ll go over marathon nutrition in more detail next week, but for now, be sure to eat before your runs, during any run longer than 60 minutes, and fuel well after your run.

Enjoy week 12, because next week is an up week!

About Claire

Coach Claire has helped hundreds of runners chase their dreams and conquer big goals. Her coaching philosophy combines science-based training, plant-based nutrition, and mindset techniques to unlock every runner's true potential. She's an ASFA certified running coach, sports nutrition specialist, a 2:58 marathoner, mom, and borderline obsessive plant lover.

FOLLOW CLAIRE @theplantedrunner

Take your training to the next level with a Custom Race Plan

Far more than just a running plan, Coach Claire includes strength training, nutrition and training tips, and her exclusive mental strength training course all in an affordable, custom plan designed just for you.

Related Posts