Momentum is a team sport. One good day makes the next one easier for everybody.

Effort is contagious in both directions. One person deciding to go properly on a flat day pulls the level up for everyone near them, and the next day starts from that higher point instead of from the floor. Nobody experiences this as being influenced. They just find it slightly easier than yesterday.

Be the person who goes first on the worst day this week, not the good one. You will not feel like it, which is why it counts. One session done properly changes the baseline for the whole group.