Why are you entering the dead zone everyday of the week and expecting to feel good? The red zone is maxing out your effort, reaching the top of your heart rate zone, pushing your body to the limit, and stressing your muscular and cardiovascular system. Those workouts are important, but not everyday. Those training sessions should be strategically placed where you can make sure to put your best foot forward as well as have a solid recovery.
The red zone provides the stimulus of anaerobic, high-intensity, glucose burning, short term maximal efforts. Depleting these glucose stores require a re-fueling AKA…Rest and recovery.
The yellow/green zones are aerobic, low-intensity, fat burning, long term moderate efforts. These fat stores last for hours and stress the body less, requiring less recovery and rest.
20% of your time should be spent training in the red zone, while 80 % of your time should be spent training in the Green/Yellow zone. This looks like 1-2 days a week training in the red, and 4-5 days training in the green/yellow.
Balancing your efforts like this will keep your hard efforts hard, and put less stress on your body during the other training sessions which provides more energy for your day.