I tell my yoga classes frequently (and my kettlebell classes not frequently enough) : THIS IS BIGGER THAN YOU.
When was the last time you stopped to think about that? What you are doing on the mat, on the deck, with the bell is far greater than you. What you are doing - whether you know it or not - is contributing to the easing of suffering for those around you. YOU are changing the world by down dogging, kettlebell swinging and taking some diaphragmatic breaths.
It took me a while to figure this out, because anything resembling fitness seems intrinsically selfish. (And in many circles, it is rooted in a place of self-disgust. "I need to be different in order to be acceptable.") But I've said before that kettlebells and yoga are - to me - Yoga: the process of turning inward for the purpose of showing up more authentically.
My teacher says, "What happens on your mat happens in your life." When I show up with my dark, my joys, my frustrations, my anxieties, my injuries, my strengths on a regular basis in the studio -- I have more of a tendency to show up with those things on a daily basis. Showing up with those things on a daily basis allows me to be with other people in their own joy and shit and pain and hope.
Metta meditation asks us to start the series of blessings and compassion: with ourselves. THEN we get to start extending compassion and hopes of joy and peace to those around us! Because when we do not believe we are worth of the beauty and relief and reality of freedom and happiness, we are not capable of easing the suffering of those around us. When I come to my mat or press a kettlebell or run around outside to practice being happy and free? I get to start the process of putting myself in a position to help others do the same!
SO. I will tell you again: What you do MATTERS. What you are doing is BIGGER THAN YOU. Coming to your yoga mat. picking up a kettlebell. going for a walk. is a HUGE responsibility and blessing...because you are undertaking the life's work of easing the suffering of those around you on chaturanga, one swing, one step at a time.