There are different kinds of force : gravity, Archimed power, resistance, friction etc. 2 or more bodies have a contact from distance or by touching each other.The earth, the sun ans the moon get in contact from a long distance. The distance relation exposed by physical space.The gravity is set around the bodies with heavy mass. WHAT GRAVITY IS ?  
The weight of a body on the surface of a heavenly body is the reaction force caused by the acceleration of the surface of the heavenly body away from its centre. Under the influence of Earth attraction bodies can be exist on our earth.The attraction  always moves towards the earth center.The bodies of heavy mass are pulled towards each other. Therefore a horse with heavy weight and the earth pulled towards each other.This causes reduce of horse speed.Because there formed 90 angle between the horse movement and the earth attraction.    Mongolians have a tradition to lose exess weight of race horse by reducing and limiting their food.At a jump mass of the horse is distributedat 3 main levels of mpotion:  
1. Moment of accumulation mass of the horse on back 2 legs
2. Moment of equalizing mass of the horse on 2 back and forward legs
3. Moment of accumulation mass of the horse on  forward and back  2 legs.
At the moment of equalizing mass of the horse on 2 back and forward legs the horse passes long distance.