I mostly do 200m drag races with my training partners, starting from 20mph. Full easy recovery between them. No shifting during the sprint -- choose your gear carefully -- experiment a bit. We're good for 7 or 8 once a week.

Sometimes we start from a near standstill, sometimes we lead each other out from 25, and move briskly up to 35 before the sprint -- but not briskly enough to drop each other.

We also do sprint pyramids (totally evil): 5s on, 5s off, 10 on, 10 off...15/15, 20/20, 25/25, 30/30, 25/25, 20/20, 15/15, 10/10, 5/5. It's 6 minutes of pure hell. Each sprint is as explosive as possible for its duration. Try not to puke.

Mostly we just do the drag races though...