The plan: Your weeks should include an interval workout, a long run, and two to three easy runs, says Gaudette. If you're racing a 5K or 10K, start with 8 to 12 x 200 meters at goal pace (or a moderately hard effort) with 30 to 90 seconds recovery. Every other week, add one or two repeats and after about four weeks, bump up the distance (aim for 6 to 12 repeats of 400 meters for a 5K or 800 meters for a 10K).
For a half or full marathon, start with 2 to 3 x 1-mile repeats at goal pace (or a comfortably hard effort) with 90 seconds rest; work up to 3 to 4 x 2 miles with 30 seconds rest. Begin long runs at half your race distance, and add one to two miles each week. Do three 4- to 6-milers before a 5K or 10K, several 10-milers before a half, and one or two 20-milers before a marathon. (Are you training in the right gear? See our list of the best new running shoes to find out.)
Nail a PR
Experienced runners know the value of completing a variety of weekly workouts. The trick lies in elevating what's worked for them in the past to reach the next level. "The body needs different stimuli and challenges to get a boost," says Wissolik. Having a plan ensures that you incorporate upgrades without overdoing it.
The plan: Whatever your target distance, do weekly long runs and intervals, and add a third key workout; alternate weeks doing a tempo or a progression run, says Gaudette.
Tempos will increase your lactate threshold: Run at 20 to 45 seconds slower than race pace, gradually increasing the distance until you can complete a 5K, a 10K, or half the distance of a half-marathon or marathon (depending on your race length).
Train to push through late-race fatigue with the progression run: Begin each run about 20 seconds slower than goal pace; speed up each mile so you're running the final mile 10 to 20 seconds faster than race pace. Build distance according to race length.race.