Instead of counting steps. Or calories. What if you counted how many times you made someone feel good?
What would be your score at the end of the day?
One point for every time you said something nice to someone. Or acknowledged how they felt. Or helped them. Or listened to them.
Minus a point if you criticised someone. Ignored them. Attacked them. Judged them.
Would you have a high score at the end of the day? Or a low one. Or even a negative score?
And how would your score be related to how YOU then felt?
Would causing happiness in others also cause happiness in you?
Try it. Play the game.
Keep the score.
And feel the effect.
Keep the score.
And feel the effect.

NB: This game isn't just about altruism. Nor just personal gain. It's about creating a self- sustaining cycle of positive compassion - both within you and around you. 
More info... https://positivepsychology.com/self-compassion-books/

More info... https://positivepsychology.com/self-compassion-books/