Total duration: 12 minutes
Intervals: 24
Lead-in: 10 s

Interval breakdown

Block 12 rounds

Hard 30 s

Float 30 s

Billat's 30-30 protocol: 30 s at 100% vVO2max alternating with 30 s at 50% vVO2max; session length is 2-2.5x your time limit at vVO2max, twelve reps here