Race

What a funny word.  My first thought, I have ran in races.  I have completed the Lincoln 1/2 Marathon 3 years in a row.  I have done fun runs this year, too.  The fun runs are A LOT of fun.
However, run, also, makes me think of the little balls of energy that are forever in motion around here.  And, recently how I have felt stretched to thin as I try to keep up with them and do somethings apart from them.  I race all day long from the time my feet hit the floor till I crawl into bed and pass-out from exhaustion.
I have been working on figuring out again, for like the millionth time in my life, how to say, "No."  And, then, I walk into church to hear a sermon on needing to say, "Yes."  I can't be stretched thinner.  But, we are to help our fellow Christians.  How do you do the things preached about from the Bible and not stretch yourself to thin?
Being a stay-at-home, home schooling, mama of 3 seems like a full-time, and I don't mean just 40 hours a week, job.  However, if I, then, want to spend time on my hobby/passion teaching pregnant couples unmedicated childbirth, and occasionally working as a doula.  Plus, take on helping in the church nursery because they need help and helping with Sunshine Bunch because they need help and having fellowship and getting to know the other ladies at our church.  Plus, BSF, Cub Scouts, and AWANA.  Plus, ministering to my unbelieving family in the hopes they will see Christ in me and want to get to know him too...
Where do I say, "no"?
How do I say, "no"?