racewalking

The sport of walking for speed, the rules of which require the racer to maintain continual foot contact with the ground and to keep the supporting leg straight at the knee from first contact with the ground until that leg is directly below the upper body.

A sport in which people try to walk as fast as possible, subject to the constraint that at least one foot must be on the ground at all time (or else they would be running). Also called speedwalking.

Present participle of racewalk.