Strong Fitness Brand Shirt Designs

This is what a business in United States was looking for in their t-shirt design

I am launching a fitness brand of t-shirts. I plan to have designs and quotes to inspire strength, health, and fitness. This is a first swing at designs, but am hoping to find a source for fairly regular design updates so we can keep adding designs to our line.
I'm open to design ideas. I like vertical designs too... like a thin design/words that go down the middle of the back, or the left side of the front. Maybe just something that isn't the same ol' square image in the middle of the back. Read more