It feels stupid till you get use to it, but when you are riding a bike you should not have to use any force to pedal.

Except maybe for really hard fast accelerations and for times you are climbing a hill and you don't have a lower gear ratio remaining to shift into.

You might check that your saddle is at the proper height. Maybe measure from the BB center to the top of the saddle where your sit bones touch and let us know that measurement. Though my preference is from the pedal when furthest away to the same place on the saddle.