By Elizabeth Comeau, Boston.com staff

If you are anything like us, your life is jam-packed: Between work, family time, and various obligations you may feel like you don't have time to do it all. Pile on top of that your desire to give back to a charity or your community and there may be even less time you spend on taking care of yourself and fitness. So, to help you multitask, we've rounded up various ways you can use your workouts and exercise to help change the world...