That's not really a sprint-exercise; it's intervals for building muscle-strength. It does help build strength to use one higher gear for 1-min intervals. However, I find for the time-spent, it's much more efficient and quicker to just go to the gym and do squats, leg-lifts and calf-raises. There is only only so much strength you can build up before you gain too much weight that cancels out the increased strength. So you need to address both. One is to maximize muscle contraction-force through strength-building exercises. Then you also have to work on sprint technique to develop as much power as possible from the strength that you do have.

In my experience (10-years racing, 7 in 1-2-pro), most racers are darn close in strength and fitness. When you're neck & neck with someone at +40mph, what's going to get you that last 0.5mph to cinch the win is being able to get whatever strength you have down to the wheels as efficiently, smoothly and as quickly as possible. It's very rare that you're going to win a sprint using a bigger gear than something that spins at 130rpms.