Jump to: The Threshold Interval Workout Every Runner Needs How to Master Cruise Intervals Ask any coach about the most important speed workout on a half or full marathon training plan , and they’ll probably tell you it’s a threshold run . These sessions help you run faster for longer, raising your lactate threshold ceiling, or the most intense effort you can sustain while still clearing lactate, which eventually slows you down. These workouts also improve your overall endurance, explains Brian Rosetti , certified run coach and founder of V.O2. Executing threshold efforts requires running at a comfortably uncomfortable pace, which can feel pretty difficult to hold for a long period of time. That’s why Rosetti recommends cruise intervals as the smartest place to start.…