Try this one-hour run from One-Hour Workouts!
Running benefits more from aerobic endurance work than any other type of training. So when it comes to speedwork, the top end of your aerobic zone (VO2max) is more crucial than anaerobic work.
VO2MAX Is Max
However, because running generates higher heart rates you can’t run as much at VO2max as you can bike or swim. For most people the longest they can last at VO2max is 10 minutes nonstop. So it’s not a good idea for your sessions to exceed 10 to 15 minutes at VO2max.
10 min.: Easy running RPE1, with a few moderate effort springs RPE2
5-8 x 600 m: Slightly faster than 5K pace RPE 4, 2-min. rest between reps
10 min.: Easy running RPE 1
Don’t overdo this workout, because the minute you go anaerobic you are no longer developing VO2max. However, because this workout is about speed, if you’re in doubt then do as any reps as you can manage. Fewer reps at the right pace or eff ort is better than 8 reps at a slower pace or eff ort. But remember that the right pace or effort is only marginally faster than 5K race pace.
This workout is from One-Hour Workouts, a collection of 50 swim, bike, and run workouts from top triathlon coaches that anyone can fit into a lunch hour–including warm-up and cool-down. Each of the 50 workouts in One-Hour Workouts are tightly focused on one goal so that athletes can get a quality training session in just one hour. Athletes can choose from base, tempo, or speed workouts in each sport to match their training plan’s goal for the day.