When we ride, particularly road, we're pulling forward into the bars, bending the spine, and pulling the stomach in. The lower you get, the faster you go - but a lot of people lack the flexibility to get the perfect position.
In this video, covering trunk (or spine) flexion and extension, you'll improve your performance by getting more of an aerodynamic position and a flatter back on the bike.
In fact, resident Road.cc yoga expert Karen Burt gives examples of people who manage to get their postions up to an inch lower, giving them some serious advantages.
Here she shows some simple exercises to relax and open out the spine, and we can check out Tony's 'sinking' posture as an example of how not to look on the bike:
After an unpromising start, having to be bribed by her parents to learn to ride without stabilisers, Sarah became rather keener on cycling in her university years, and was eventually persuaded to upgrade to proper road cycling by the prospect of a shiny red Italian bike, which she promptly destroyed by trapping a pair of knickers in the rear derailleur. Sarah writes about about cycling every weekend on road.cc.