When you train for a marathon, every workout you do has a specific pace associated with it so you gain the most value from it. Use these pacing guidelines for your workouts.
Recreational runners should follow these guidelines for tempo runs and intervals:
Tempo runs (runs at your tempo pace, which corresponds to your fastest sustainable aerobic pace)
About 10 to 15 seconds per mile slower than the pace you run for a 5K race
Equal or very close to the pace you run for a 10K race (if you’re slower than about 53:00 for 10K, your tempo pace will be slightly faster than 10K race pace)
80 to 85 percent of your maximum heart rate. You can determine your max heart rate by running a mile on a track (usually four laps on an outdoor track) while wearing a heart rate monitor and running each lap faster than the one before it so that you’re running all-out over the last lap.
Intervals (periods of hard running interspersed with recovery periods)
Between mile and 2-mile (3K) race pace
About 20 to 25 seconds per mile faster than 5K race pace
About 40 to 45 seconds per mile faster than 10K race pace
95 to 100 percent of max heart rate
Competitive and highly trained runners should follow these guidelines for tempo runs and intervals:
Tempo runs
About 25 to 30 seconds per mile slower than 5K race pace
About 15 to 20 seconds per mile slower than 10K race pace
85 to 90 percent of max heart rate
Intervals
Equal or very close to 2-mile (3K) race pace
About 10 to 15 seconds per mile faster than 5K race pace
About 25 to 30 seconds per mile faster than 10K race pace
95 to 100 percent of max heart rate
