“Exercise in the morning before your brain figures out what you’re doing” is a saying that has been printed on several posters. “I have to exercise early in the morning before my brain figures out what I am doing” is a quotation that has been attributed on many websites to exercise expert Marsha Doble; it been cited in print since at least 1998.
 
   
The Quote Garden
Quotations about Exercise
I have to exercise in the morning before my brain figures out what I’m doing.  ~Marsha Doble
 
Fitness and Exercise
Quotes
I have to exercise early in the morning before my brain figures out what I am doing. (Marsha Doble)
 
ChaCha
Marsha Doble is a famous motivational speaker and exercise guru. She has helped many people lose weight and get fit.
 
Google News Archive
25 August 1998, Cedartown (GA) Standard, Cedartown Plus, pg. 7, col. 1:
I have to exercise in the morning before my brain figures out what I’m doing.
—Marsha Doble
 
24 January 2000, The Advocate (Baton Rouge, LA), Smiley Anders column:
“I have to exercise in the morning before my brain figures out what I’m doing.”
 
Google Books
The 2,548 Wittiest Things Anybody Ever Said
By Robert Byrne
New York, NY: Touchstone
2012
No. 1,177
I exercise in the morning before my brain figures out what I’m doing. —Marsha Doble