Getting fit enough to race -- rather than merely complete -- a 5K, or 3.1-mile road race, takes determination and planning. If you're starting at a beginner's fitness level, give yourself about three months to do the endurance runs, speed work and pacing practice necessary to make the most of your abilities come race day. After picking a goal event, work backward on the calendar to determine when your formal training should begin.
Develop Your Basic Endurance
Run at an easy- to moderate-intensity level for 20 to 45 minutes three to five times a week. How far and how often you run will depend on your current fitness, athletic history and overall health.
Set aside one day a week for a longer run. If you average 20 minutes a day on the other three to five days, aim for 50 on your long-run day. If you average closer to 45 minutes a day, run for an hour or more.
Rest or do cross-training one day a week. Alternate exercises may include cycling, an elliptical-trainer workout, cross-country skiing, yoga, Pilates or any other workout of your choice.
Do this routine for about six weeks. During this time, you'll run anywhere from about 20 to about 40 miles a week, but it's acceptable and often more convenient to go by elapsed time rather than distance covered.
Build Your Speed
Complete a lactate-threshold run or a set of VO2 Max intervals once a week. More experienced runners may do one of each.
Run for about 20 minutes at roughly 25 to 30 minutes per mile slower than your 5K goal pace to do a lactate-threshold run. You can do this on a track or on a road course.
Do about 4,800 meters, or 3 miles, of running at or just below your 5K goal pace to do a VO2 Max workout, breaking it into segments of 200 to 1,600 meters and interspersing them with rest periods half as long as the time it takes to complete the fast portions. This is best done on a track.
Follow this scheme for about eight weeks before moving to the tapering phase.
Taper and Race
Reduce your mileage by about one-third in the two to three weeks before your 5K race.
About seven to 10 days before your 5K, do a two-mile time trial on a track. Aim for an even pace. Make whatever pace per mile you can maintain in this workout, or a few seconds slower than this, your firm 5K goal pace.
Go out more slowly than you think you should in the race, as adrenaline and the people around you are likely to "pull" you to a faster start than you realize. Hydrate properly before the race no matter what the weather is like, and tightly knot your shoes.