Morning cardio - Where there's a will there's a way

Good morning everybody :)
Early mornings are best used sleeping, or for restless souls: cardio!

High intensity intervals before breakfast are my favourite fat burning exercise. Before such hard workouts on an empty stomach I always drink BCAA (branched chain amino acids). The body then uses this supplement as energy instead of tearing on your muscle mass. Today my routine was:

- Warmup: 20 minutes slow run
- Guerilla cardio: 8x 20 seconds max sprint, 10 seconds rest in between.
- Cool down: 15 mintues slow run to get home.

Tired and happy to get home to a tasty protein shake :)

Whats your favourite fat burning routine?