Gravity affects speed, one of the six components of skill-related fitness. Is this true?

Answer 1

It depends how you are moving. If you are running around a track with horizontal direction of motion then no, because there is no force due to gravity in the horizontal direction. If you throw a basketball in the air, or high jump, or jump off a chair, you or the basketball will accelerate downwards because of the force due to gravity so gravity will affect speed in that case.