“You can’t out-exercise a bad/poor diet” means that if one’s diet is poor, then exercise will not overcome that. “We all know that it is very difficult to out-exercise a bad diet” has been cited in print since at least 2006 and the adage quickly became popular on the Internet. The saying’s origin is unknown.
 
“Fitness is 20% exercise and 80% nutrition. You can’t outrun your fork” is a similar saying.
 
       
T Nation
MikeTheBear
3-22-2006, 03:23 PM
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We all know that it is very difficult to out-exercise a bad diet.
 
6 March 2007, Rocky Mountain News (Denver, CO), “A big loser makes a great role model” by Erika Gonzalez:
I had to learn that you can’t out-exercise a bad diet.
   
T Nation
ChrisKing
07-22-2007, 08:37 AM
Of course it’s your diet. I can’t remember who first said it, but you can’t out exercise a poor diet. If you want to get leaner, it’s all about what you put in your mouth.
 
10:10 Wellness
May 18, 2008
Travel Well!
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There’s a saying in the fitness industry: “You can’t out-exercise a bad diet.” So no matter how often you hit the hotel gym (and not many travelers do at all), you won’t be able to fight off weight gain if you continue to down processed foods and sugary beverages.
 
Fitness Overhaul
You Can’t Out Exercise A Bad Diet
by on February 28, 2010
No matter what type of diet or what type of exercises that you are doing, losing weight all comes down to creating a caloric deficit. To do this you can decrease your calories by eating less or exercising more. Between the two, decreasing your calories through diet is by far the best way to cause a calorie deficit. In reality, you just can’t out exercise a bad diet.
 
twirlit
Sorry…You Can’t Out Exercise a Bad Diet
Posted on March 12, 2010 by Kelly Turner
There was an article published on TIME magazine’s website entitled “Why Exercise Won’t Make You Thin” that got my Under Armour in a bunch.  The article claimed that exercise was pointless when trying to lose weight because exercise increases your appetite, causing you to over eat, and thus, not lose weight.
   
Google Books
The Women’s Health Big Book of Abs
By Adam Bornstein
New York, NY: Rodale, Inc.
2012
Pg. ?:
When it comes to weight loss, you can’t out-exercise a bad diet.
 
Naperville Sun (Aurora, IL)
Nicki Anderson ponders working out harder or eating healthier
By Nicki Anderson .(JavaScript must be enabled to view this email address) May 21, 2012 6:26PM
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There is no doubt we aren’t nearly as active as we were at least 40 years ago. Compound that with the quality of foods that we’re eating, more sugar and fat in our diet, and it’s literally a recipe for disaster. As more research surfaces, the adage, “You can’t out exercise a bad diet,” has never been more fitting.