Cycling is a great, low impact way to keep fit. The same principal as for running applies here, we want to cycle as efficiently as possible.
This means time is spent to check the set up of the bike for both comfort and the ability to apply power to the pedals. This is done initially on a wind trainer and then verified outside.
Whether you use cycling as a low impact way to stay fit and healthy, to enjoy the scenery or to take part in cycle events or duathlons / triathlons then there is a high value in being comfortable and efficient whilst on the bike.
Of course, the saddle itself your body will need to adapt to for comfort here!