The Twin Cities friends who put on the 30 Days of Biking in April are at it again for September hoping to double the 500 participants they had this spring. Their site challenges you to ride your bike every day this month whether it’s the daily commute, a century ride, or around the block. If you feel moved, Zachariah Schaap and Patrick Stephenson ask you to share via Twitter your experiences.

Here are the rules:

The only rule for 30 Days of Biking is that you bike every day for 30 days—around the block, 20 miles to work, whatever suits you—then share your adventures online. We believe biking enriches life, builds community, and preserves the Earth.

My wife, Amy, participated this spring and wrote about it in a 6 part series. Give it a read to get inspired.

Register for the 30 Days of Biking here.