How to Use 5k/10k Races in Your Marathon Training

How to Use 5k/10k Races in Your Marathon Training

Adding shorter, faster races into your marathon training can help you become a faster, hardier runner. Here’s how to get the most out of your “B” races.

The long buildup to a marathon — often a 5- or 6-month training block — demands keen focus to keep your eyes on your race goals. One way to break up your training cycles is to sprinkle in some shorter races, like 5ks or 10ks, to give you something to look forward to and to help you train to be a better marathoner. 

Classic Marathon Training

During a typical marathon build-up, I like to see runners working on a few different skills including strength, economy, and race-specificity. Standard sessions include hill repeats for strength, drills and strides for improving economy, and long tempo sessions at marathon pace for race-specific training. Each one of those runs has its place while each block builds on the one before it. 

Switching it Up With 5k and 10k Races

As you work faster, shorter races into your training cycle, keep in mind that they can replace your speed and strength session for that week. For example, on the weeks that you incorporate 5ks and 10ks, drop the speed sessions to let your legs freshen up a bit. 

Training Tip: Add in a Long Run the Day Before Your Short Race

Running a 10k has the same advantages as a speed session, but I like to see runners add in a long run the day before so that you learn to push hard when you aren’t feeling your best. For example, if you have a 2- to 2.5-hour-long run that includes some marathon pacing, try running two hours the day before your 10k with 60 minutes at marathon pace (or Zone 3 HR). This won’t leave you feeling super fresh the day of your 10k, so add in an extended warm-up before your race — think 2.5-3 miles or 25-30 minutes — and you should start to feel a little better during the race. 

My recommendation would be to negative split the 10k (i.e., running the second half faster than the first). To do so successfully, start at half marathon pace for the first two miles, then settle in and run at 10k pace up until mile four or five, and then try to push just a little faster than 10k pace for the remainder of the race. Whether you can achieve this or not, the goal is to be able to push hard when you are tired, just like you would during your marathon. 

Once you have finished the race, your work isn’t quite done. Cool down for at least two miles to give you a total of 10-11 miles that day. Coming off the long run the day before makes this a solid combo for two days of training. Be smart about not overloading in the following days, as you’ll likely want to focus on recovery — think mobility work, yoga, and massage. 

Training Tip: Push Through the Pain to Better Prepare For Your Marathon

Running at 5k pace is at the top end of what you’d be running during marathon training. These short, fast races will not only help with your overall speed but also your ability to dig deep in the marathon when it may become physically painful. 

Using the same pre-10k run plan with a long run the day before, the strategy for a 5k is a little different. Even though you’ll be tired from the long run the day before, you’ve got to really drop the hammer in the 5k and go for it. This is a great chance to see what you have in the tank when you are fatigued and to teach yourself to push through tough mental and physical boundaries. In your upcoming marathon, this is what makes the difference between reaching your goal and not. 

Tuning up with a variety of training will prepare you for whatever your marathon throws at you. Get ready to rock your “A” race by adding in some fun, shorter “B” races that will help you push through new levels of discomfort.

Mike Ricci

Mike Ricci, USAT Coach of the Year, USAT Level 3 Elite Coach and a Training Peaks Level II Certified Coach.  He is the owner and founder of the D3 Multisport coaching group, through which he coaches all levels of athletes from beginner to elite. One of their key coaching philosophies is no junk miles.  They help athletes utilize their time effectively as they pursue their goals.  Mike’s credentials include the University of Colorado Triathlon Team and guiding them as the Head Coach to four consecutive collegiate National Championship titles from 2010-2013. Mike has written training plans for Team USA several times, was the USAT World Team Coach in 2017, and has helped many athletes to qualify for the Ironman World Championships in Kona. You + D3 = Success (Learn More!).
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