SAs favor candidates who have participated in varsity athletics and who are physically fit. Those concepts are related but not necessarily one and the same.
Varsity athletics help someone gain traits such as leadership, teamwork, discipline, resilience, perseverance, grit and time management. While varsity level isn’t a must, it does imply a certain level of achievement of those traits.
Physical fitness can be achieved outside of varsity sports. It’s mainly measured by the CFA, because being a varsity athlete is no guarantee that one is fit in the eyes of an SA.
So it’s as simple as this: If you don’t play a varsity sport, use your other experiences to demonstrate that you have the desired traits. Most, but certainly not all, cadets/mids played a varsity sport. It’s preferred, but not a showstopper if you didn’t.
And work toward high performance on the CFA. Show that you’ll be able to handle the physical demands of academy life and active duty. Officers lead from the front, and that features physical fitness at a high level.