There is a lot of emphasis on having a “Bike Fit”  (which we can do to a certain extent) to the athlete, but the athlete can help themselves with their posture and position on the bike.

This will help in the athletes power/ performance as well as injury avoidance.

With correct pelvic alignment the athlete will recruit the stronger gluteus muscles and be more powerful.

But aside from this the spine is meant to be in a certain alignment, this alignment must be respected in order to avoid injury/pain/discomfort.
Pain and discomfort will not help performance, the athlete will back off subconsciously and not have the mind on the job because they will be distracted by the discomfort.

Biomechanics Assessments are advisable for knowing where restrictions are and avoiding injury and improving strength and power.