(1) The majority of athletes taking part in the races are right-handed. Hence, the right-hand side limbs of their bodies are physically better developed and heavier than the left-hand side limbs. As they run right hand side of their bodies tend to pivot towards that side. Therefore, running becomes easier and safer especially at the curves of the racetracks when running in counter-clockwise direction.
(2) Another interesting aspect is that the left leg is somewhat shorter than the right in case of most of the people. It means that greater energy being concentrated in the right leg, body of the athletes tends to veer towards right side. But the distance to be run on oval shaped racetrack is not the same for both the legs. Running in the innermost lane after completion of the first lap or the round of track in the case of races of 800 meters and longer distances the left leg must keep nearest to the inner line of the innermost lane where it has to cover less distance than the right leg.