How to keep momemtum while moving up an incline?

Whether you are running, cycling or attempting to move a heavy object, an incline can greatly impact your ability to do so. Depending on whether you are attempting to climb or descend, you may view such an incline as either an aid or a hindrance. Much of this variability depends on your momentum, with an incline or decline determining whether you gain or lose momentum as you move.
Momentum
Despite being a common term with numerous possible interpretations, momentum in physics is defined as the product of an object's mass and the speed at which it is traveling. While you may tend to attempt to conserve your momentum or hold it constant while running, the addition of outside forces can either increase or decrease your momentum. Such external forces include increased weight, wind resistance, changes in surface and the angle at which you are moving.
Moving Up an Incline
Although the force of gravity is a constant, its effects on an incline account for much of the changes in momentum that you may experience. On a flat surface, the force of gravity acts exclusively in a downward direction. While it continues to do so as you move up an incline, the incline serves to divide the force of gravity into two forces: one that pulls perpendicular to the incline and helps you to stay on the surface and another that pulls you downward parallel to the incline. Provided that you continue to use the same amount of effort and energy as you move up the incline, the force of gravity acting against your climb will result in a decrease in speed, thus decreasing your momentum.
Moving Down an Incline
With the force of gravity helping to pull you down an incline, conserving your momentum as you approach a downhill slope can be difficult. Opposite to the effects of climbing up an incline, going down an incline without attempting to compensate for the added downward force will cause you to accelerate. As such, the further that you go downhill without attempting to slow yourself down, the more your speed and momentum will increase.
Conserving Momentum
For the competitive runner or cyclist, attempting to maintain a constant speed while training outdoors can lead to gains in endurance, strength and technique. Due to the effects of gravity on an incline, attempting to conserve your speed and momentum while climbing hills requires you to act against forces not present on level ground. While you may be tempted to let gravity do its work as you go downhill, attempting to maintain a constant speed as you descend can be an equally difficult workout, working muscles different from those used in climbing. With knowledge of these effects of an incline on momentum, you may be able to improve your training program simply by attempting to conserve momentum as you move up and downhill.