Red Endurance Intervals test your ability to create power as long as possible using your lactic system. That means that you need to work at 100% intensity for 40-60 seconds while driving your heart rate to its maximum.
You’ll need to actively rest for 1-2 minutes to lower your heart rate back into the blue zone before repeating the interval. This rest period helps build your aerobic fitness and improves your ability to recover between explosive bouts.
Since this is such a high-intensity method, you don’t need to do many reps to stimulate adaptation.
Focus on maintaining good technique, especially as you begin to fatigue.
Interval Summary
Goal: Push the lactic system to the limits of energy production to build lactic power, while developing the aerobic system at the same time.
How: From the top of the blue zone, go 40-60 seconds at 100% intensity while focusing on maintaining good technique. Actively recover back down to the top of the blue zone over 1-2 minutes. Repeat for 2-4 reps.
Exercises: Use low-impact cardiovascular exercises to minimize joint stress.