http://www.musclemedia.com/training/hiit_table.asp
or
Week 1, Workout 1: 20 minutes @ 70% of HRmax
Week 1, Workout 2: 25 minutes @ 70% of HRmax
Week 1, Workout 3: 30 minutes @ 70% of HRmax
Week 2, Workout 1: 20 minutes @ 75% of HRmax
Week 2, Workout 2: 25 minutes @ 75% of HRmax
Week 2, Workout 3: 30 minutes @ 75% of HRmax
Week 3, Workout 1: 20 minutes @ 80% of HRmax
Week 3, Workout 2: 25 minutes @ 80% of HRmax
Week 3, Workout 3: 30 minutes @ 80% of HRmax
Week 4, Workout 1: 20 minutes @ 85% of HRmax
Week 4, Workout 2: 25 minutes @ 85% of HRmax
Week 4, Workout 3: 30 minutes @ 85% of HRmax
Week 5, Workout 1: 5 sprint intervals
Week 5, Workout 2: 5 sprint intervals
Week 5, Workout 3: 6 sprint intervals
Week 6, Workout 1: 6 sprint intervals
Week 6, Workout 2: 7 sprint intervals
Week 6, Workout 3: 7 sprint intervals
Week 7, Workout 1: 8 sprint intervals
Week 7, Workout 2: 8 sprint intervals
Week 7, Workout 3: 9 sprint intervals
Week 8, Workout 1: 9 sprint intervals
Week 8, Workout 2: 10 sprint intervals
Week 8, Workout 3: 10 sprint intervals
Week 9, Workout 1: 11 sprint intervals
Week 9, Workout 2: 11 sprint intervals
Week 9, Workout 3: 12 sprint intervals
Week 10, Workout 1: 12 sprint intervals
Week 10, Workout 2: 13 sprint intervals
Week 10, Workout 3: 13 sprint intervals
Week 11, Workout 1: 14 sprint intervals
Week 11, Workout 2: 14 sprint intervals
Week 11, Workout 3: 15 sprint intervals
Week 12, Workout 1: 15 sprint intervals
Week 12, Workout 2: 15 sprint intervals
Week 12, Workout 3: 15 sprint intervals
Which HIIT routine do you guys like better?