"Don't look up. When you're tired, do whatever you can to keep moving and don't look at anyone else. What they do doesn't matter. Worry about yourself and don't look up."
I think that is amazing advice. Don't worry about other people. If you're struggling, keep pressing on in your own little world. The moment you look up you'll see that rock star who is just murdering the workout and it makes you realize how far behind you are. Feelings of inadequacy creep in and it slowly kills your workout. In a perfect world we would use those icons of fitness as motivation. However, to the new person they are just a sign of how far they have to go.
Look down at the ground and keep on trucking. Someday you will be that person new people aspire to be like.