I have a strange problem, I know:

I can't run fast on a downhill.

I mean, I can run faster than I would on the flats, but my running friends totally beat me down the hill. They're running at least 30-50% faster than me. I catch up on the uphill, and usually pass them, though. But I have a race with a long downhill coming and I'd like to do better.

I have a short stride which I think is really helpful going up, but I can see they take longer steps on the way down.

Any tricks?