Lowering your time in a 10-kilometer, or 6.21-mile, running race requires adding both aerobic endurance and aerobic power to your training regimen. If you're new to running, you can improve for months using just easy distance runs alone, but after that, you need to undertake more specialized workouts. Focusing on your pace per mile rather than your goal 10K time during training is the best way to see a real difference come race day.
Most of your preparation for a 10K race will involve ordinary distance runs lasting anywhere from two miles to 10 miles or more, depending on your experience level, current fitness and overall health. The good news is that these runs don't need to be hard for you to reap their benefits -- working in the range of 65 to 85 percent of your maximum heart rate is ideal.
You can estimate your MHR either by subtracting your age from 220 -- the tried-and-true method -- or by subtracting 88 percent of your age from 206 -- the latest method targeted to women. These runs should last anywhere from 20 minutes to over an hour, and you can mix it up from day to day. Running with a partner who's in your general fitness range is a great way to make the miles fly by.
Keep track of your per-mile pace so you have a general idea of what to shoot for in your 10K. If, for example, an 11-minute mile feels pretty easy, you can aim for 9 to 10 minutes per mile in the race.
Distance runners' training typically includes one run a week that's significantly longer than any of the other three-plus efforts. This run should be about 25 to 40 percent of your total weekly mileage. The rationale for this practice is that your body begins to use fuels differently after about 75 to 90 minutes of exercise, and in a way that prepares certain muscle fibers to use fuel more efficiently at higher intensity levels, such as those you encounter in a 10K race.
Mile repeats make you fitter and therefore better equipped to handle a fast pace, prepare you mentally for running hard and give you a concrete pace target to shoot for in your 10K. Warm up for these workouts, best done on a track but also suited for an accurately measured road course, with about 10 minutes of light jogging. Then do three or four one-mile runs at what feels like 10K race pace -- too hard to hold a conversation but not so hard that it hurts. Rest for three to four minutes between these. If you can run these at a consistent pace from one rep to the next, you can very likely match or at least approach this pace in your 10K, where you should be given split times at each mile. For example, if you can run four repeats in 8:11, 8:04, 8:14 and 8:10, you can reasonably expect to average close to 8:15 pace in your race for a total time of around 51 to 52 minutes.
Tempo runs are about 20 minutes long at a pace you could hold for about an hour going all-out. This intensity matches the heart rate at which your body starts accumulating lactic acid faster than you can clear it. The result is your body becomes more efficient at working at higher intensity levels. Tempo runs should feel as if you're going easier than in mile repeats but harder than on an everyday run.
L.T. Davidson has been a professional writer and editor since 1994. He has been published in "Triathlete," "Men's Fitness" and "Competitor." A former elite cyclist with a Master of Science in exercise physiology from the University of Miami, Davidson is now in the broadcast news business.