Turning Marathon Fitness in 5K and 10K PRs




You worked hard over the last few months to prepare for your marathon or half-marathon. You put in the miles. You completed the long runs and on race day, you performed like a champ. Congratulations! So now what?

You know you need to mentally and physically recover from the half/full marathon, but you don’t want to lose the great fitness level you’ve attained through all the training. Plus, your race performance left you stoked for more. You’ve got the bug and are ready to get back on the roads, to pin that number to your chest and to blow the rust off.

And why not? There are plenty of holiday races you and your running buddies want to do. And, without the burden of extra miles and marathon-type long runs, you can simply run and race fast.

You’re in luck. I’ve found that you can carry your half and full marathon fitness into 5K and 10K racing. You just have to be smart. My advice for carrying your marathon fitness into shorter races is actually quite simple. The challenge, however, is that you must remove your “runner’s brain” and allow me to put in a “coach’s brain” for the first three to four weeks after the half or full marathon.



You don’t need me to tell you that the marathon was tough on your body. Going down steps, getting in and out of the car and settling down on the toilet offer plenty of biofeedback to let you know that muscle damage has occurred. That’s OK. It’s expected. What you must do, however, if you want to race some fast 5Ks and 10Ks in the spring, is to focus on recovery, especially during the first two weeks. Research shows that muscle damage like yours does heal, but it takes a while. The research also shows that strenuous exercise during this time delays the healing process. So, get ready to take it very light the first two weeks after the marathon. Here’s my two-week recovery plan.


Starting in the third or fourth week post-marathon, you can begin to get back into training, but focus on intensity, not building your mileage. Run 30 to 50 percent less mileage than you did in your marathon training and begin to add some surges in one to two of your weekly runs. These aren’t all-out, but rather up-tempo 2- to 5-minute surges at a medium effort (roughly half marathon effort). As you go forward in your training in Weeks 4 and 5 post-marathon, gradually build your mileage. But I still recommend keeping it at 20 to 40 percent less than your marathon mileage. With each successive week, make the surges shorter and shorter and faster and faster. As with the first two weeks post-marathon, resist the temptation to run quick too quickly. Keep things under control and use these first few surge/fartlek workouts as medium efforts.

You may have your first post-marathon race four to six weeks after the marathon, but don’t get too pumped up. These first few races are usually tune-up races or “rust busters” to help you remember what it is like to challenge yourself over a shorter distance.


After five or six weeks post-marathon, you should begin to build into race-specific training. For the 5K and 10K, this usually means hitting a track or marked course once a week for some repeat 400s, 800s, 1200s or miles — all at around 5K race pace. The muscle damage from the marathon is gone, you are feeling like a runner and the reduced volume has you excited for each fast workout. The more race-specific training you can do, the better. You have the aerobic base from the marathon training, so use this time to get fast!


As you have now settled into a regular routine of workouts, it’s OK to gradually add back in some of the volume. I still recommend that you keep it less than your marathon training volume, but it’s OK to extend your long run back up to 90 minutes and to build your volume/mileage back to 80 to 90 percent of your marathon training mileage.

#5: GO RACE!

Now that you have a few weeks of training under your belt, you’ve “busted the rust” with a few early season races, and you’ve completed some fast track workouts, there’s nothing left to do but go race. With your marathon aerobic base and your post-marathon speed training, you are ready to attack the 5K and 10K distance. And, unlike the marathon where you can only race one every few months, you can race 5Ks and 10Ks week-in and week-out. So race a lot. Challenge yourself in these shorter races, but most of all, have fun. Shorter races offer a great chance to challenge yourself to see what you are made of, then hang out with friends after the race and be home in time for brunch. Not a bad way to spend a weekend.


Week 1: NO workouts! Just easy walking and light jogging.

Week 2: No hard workouts! Easy running only.

Week 3: Surge workout: 4 to 5 x 3 minutes at a medium effort (tempo run effort) with 3-minute recovery jog between each.

Week 4: Surge workout: 4 to 5 x 3 minutes at a medium-hard effort (10K tempo run effort) with 2-minute recovery jog between each.

Week 5: Track time! 5 to 7 x 800 meters (two laps) at goal 5K race pace with 400 meters (one lap) recovery jog.

Week 6: Track time! 8 to 10 x 400 meters (one lap) with 200 meters recovery jog.

NOTE: You can race as early as Week 4, but as a fun run, not a 100 percent performance.

Read more about how you can have more racing breakthroughs using Go Zone Racing – a strategy for better performance.


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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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