You may have competed in 8K races if you were on your school's cross-country team, but in general, 8Ks appear far less frequently than 5Ks or 10Ks on racing calendars.
But if you have the opportunity to run an 8K, you should seriously consider it. Though it may be uncommon, the distance represents an achievable feat even for newer runners, says Tim Bradley, a running coach and director of training for the Chicago Area Runners Association.
Already registered? Here's how to train for your first 8K race.
Read more: Proper Training for Long-Distance Running
How Many Miles Is an 8K?
An 8K is about five miles long — 4.97 miles, to be exact. Though that's only roughly a couple of miles more than a 5K (3.1 miles), training for and racing an 8K more closely resembles what you'd do for a 10K (6.2 miles), says Bradley. You'll need to pace yourself a little bit more than you would during a 5K if you want to finish strong.
To put it in context, running a 5K as fast as possible would typically mean maintaining a heart rate that's about 90 percent of your maximum. During an 8K, on the other hand, your heart rate would stay closer to 85 percent, he says.
The good news? If you've already completed a 5K or have been running three to four miles consistently for at least a few months, Bradley says you can train for an 8K in about six weeks.
At Lively Athletics, a boutique athletic store in Oak Park, Illinois, training programs for the local Hemingway 8K last eight weeks, says co-owner and certified running coach Kate Marlin.
Read more: How to Train the Week of a 10K
How Many Days a Week Should You Run?
You can safely and comfortably complete an 8K by running three days per week, says Bradley. If you have an ambitious time goal, you might want to consider four days of running per week or more. Of course, that also depends on how much you're currently running. Generally, you don't want to increase your total mileage by more than about 10 percent per week, says Marlin.
One of your weekly runs should be a longer distance than the others. You might start around three or four miles, then increase by a mile or two each week.
If you're newer to the sport, Marlin says run/walk intervals can help you add distance safely. For example, you might run for three to five minutes, walk for one minute, then repeat.
Both Marlin and Bradley recommend building up your long run until it's longer than the distance of the race — from six miles to as many as 10. "This helps make sure you're ready physically and gives you confidence," says Marlin.
If you're a more advanced runner training four or more days a week, you can add in some faster intervals, too: Run fast for a half-mile or a mile, then jog easy in between.
Keep all your other runs, including your long run, at a slower, easier pace. If you use a heart rate monitor, make this 65 percent or less of your maximum heart rate; otherwise, run at an effort that allows you to hold a conversation easily.
Training at this low of an intensity reduces your risk of injury while improving your cardiovascular conditioning, says Bradley. You can also cross train once or twice a week to boost your cardio with less impact than running (think: swimming and cycling).
What's the Best Cross-Training for Runners?
For the best race-day experience, go beyond logging your miles. Regular strength or resistance training reduces your risk of injury and can also improve your running performance. You can head to the gym and lift weights two to three times per week, or incorporate shorter sessions of bodyweight and core exercises after your runs, says Bradley.
What's the Best Strategy on Race Day?
Generally speaking, you want to stick with the same strategy, gear and food (nothing new on race day!). If you've been doing run/walk intervals during training, keep it up. That said, if you're feeling good toward the end of the race, feel free to pick up your pace.
But a word to the wise: Even if you're an advanced runner who's been training to run a specific pace, make sure you don't go out too fast, or you'll run out of gas by the end, says Bradley. Instead, begin at a controlled pace and pick things up after the first couple of miles, saving enough energy to sprint across the finish line.