Why Ultrarunners Should Race 5Ks (and How To Do It)

By Jason Koop
Coaching Director, Author of “Training Essentials for Ultrarunning”

Racing a 5-kilometer running race may seem antithetical to ultramarathon training, but there are plenty of good reasons why racing fast for 5 kilometers is beneficial for athletes training to run 50 or 100 miles.

I should preface this by saying that, while there are benefits to racing fast for short distances, it’s also perfectly OK not to. You can accomplish virtually all of the following benefits through focused training and overall racing experience. Entering races might be more fun, though.

The races, particularly the intensity and training stress, should ideally fit in with your current phase of training. A 5K race is similar in workload to a VO2 max workout, something like a standard 5×3-minute VO2 max intervals. The two are not identical, but the time-at-intensity is similar between the two and they’re close enough to be occasionally swapped. Racing a 5K during a different period (like during an aerobic endurance phase of training) is still okay, but you have to consider whether the time could be better used.

If short races and interval workouts are so similar in terms of training stimulus, why race? The best reasons are because it’s fun, it’s social, and you’re a competitor. The more technical benefits include the following.

5K Benefit: Race Intensity

You will always push yourself a little harder in a fast-moving pack than you would during a solo interval workout. You don’t want to rein that in, either. Leverage that effect and lean into it. The race/workout is going to be hard anyway, so go all in and make it really hard!

5K Benefit: Engagement

There’s a crew of runners in the Bay Area, including Dylan Bowman, Alex Varner, and 6-10 others, who get together for a weekly sunrise run up Mt. Tam. Sometimes social, sometimes a hammerfest, this weekly touch point helps the runners – many of whom frequently run alone due to the specificity of their training – connected to their running community. Entering local 5Ks is a great way for ultrarunners to connect to the larger running community in their area, especially the running clubs and specialty running stores that typically produce and sponsor the events.

5K Benefit: Logistics Practice

The pre-race process for a 5K is not that different from an ultramarathon, but you can get a lot more practice with far less racing effort by using a few 5Ks to get your routine squared away. Eating the night before and morning of, packing your gear, leaving on time, checking in, getting your race number, dealing with pre-race bathroom runs, and handling pre-race jitters are all things you can get dialed in at local 5Ks and 10Ks. A 5K can be a good low-key dress rehearsal for your goal event. The idea is to reduce the stress and uncertainty you feel going into a 50- or 100-mile race, so you can handle those logistics more calmly.

Ultrarunners’ Do’s and Don’t For Racing 5Ks

Once you’ve decided to enter some local 5Ks or 10Ks as part of your ultramarathon training, there are some do’s and don’ts I recommend.

Do: Race! As mentioned earlier, it’s going to be hard anyway, so open the throttle and don’t hold anything back. And remember to have fun and join in the post-race festivities. Racing is the fun part, even when it’s not your goal event or even the distance you’re best suited to.

Do: Warm up as you would before an interval workout. Similarly, you should go through your normal post-interval cooldown process, too. Not only will these steps further ingrain these routines, but the workload and intensity are similar to an interval workout, so you should prepare and recover the same ways.

Do: Be deliberate with your routines, including pre-race meals, pre-race packing, check-in, warm up, etc. Working out the kinks in this process is one of the most important reasons to do these races in the first place.

Don’t: Don’t make excuses. You’re not a jackrabbit who specializes in 5K races, nor are you a beginner just dipping your toe into running competitions. Nevertheless, don’t be that guy/gal who starts making excuses before the race about their long training week, or that their training for Leadville, blah, blah, blah. You know what you’re there for. Just go do it. If anything, use the opportunity to make beginners feel welcome in the running community and make some new friends.

Don’t: Don’t add more volume after the race. Some ultrarunners feel pressure to tack on extra mileage after short races, but you’re better off doing a good post-race cooldown and calling it a day. If you raced hard, the time-at-intensity was enough training stimulus for one day, and it’s unlikely that additional training will further enhance that day’s effect on your fitness and performance.

There are really two big things ultramarathon runners should know about 5Ks. First, there is no reason to actively avoid participating in short, fast races. They’re not going to hurt you; they’re more likely to help you. Second, they’re just plain fun! So, if there’s a cool race in your area and it fits into your training, go for it!