A very significant percentage of cyclists are riding with a saddle that is too high for them.
It stems from a vicious circle. You raise your saddle a few mm to experiment and feel you have more power, a few more mm and it feels even better. Too late it is when weeks have passed and you start experiencing tight hamstrings, IT-Band syndrome, lower back pain, over worked achilles tendon and/or saddle sores. The time that has passed between making changes to your saddle height and the problems you experience, will make it harder to see the connection.
The initial feeling of power is the result of our upper body being enlisted to push the pedals down. Hence the rocking motion… More weight, more power…. for a short time!
To test: Try keeping your upper body completely still when pedalling. How is your contact to the pedals at the very bottom of the stroke? You may realize that you hardly reach them at all! Solid foot and pedal contact is what you need.
Art by Volkan Akmeşe