Just like dating (or marrying) George Clooney means vacations on Lake Como, hooking up with Leonardo DiCaprio means bike rides (and lots of them). Leo has been spotted out on rides with all of his girlfriends, including German model Toni Garrn, who he's been dating for over a year and a half. We can't help but notice that Leo has a pretty obvious background of bike-riding with his babes — in addition to being great exercise and eco-friendly transportation, it seems to be one of the most common date ideas for the A-list actor. In honor of Leo's upcoming 40th birthday, here's a history:

Toni Garrn, Spain, August 2013

Emily Mace, NYC, June 2013

Erin Heatherton, NYC, June 2012

Blake Lively, NYC, July 2011

Bar Refaeli, Paris, July 2010

Gisele Bündchen, NYC, June 2005