To stay relaxed, Barry focuses on smooth rhythmic breathing, which tends to loosen the whole body and helps maintain focus and composure. On the bike, let the upper body relax so that all the energy goes into pushing the pedals. To practise, ditch the asphalt and let the bike move.
What you need: a mountain bike, a smooth, twisty, slightly downhill section of trail.
How to: Think of your bike as an extension of the body. Just as in running or skiing, let your lower body and bike do the turning while your upper body stays quiet. Keep the upper body relaxed and centred, and gently guide the bike through the turns, allowing it to move back and forth underneath your body. Your arms should be slightly bent and able to move up and down and back and forth with the bike. After practising this a few times, get back on the road and try to emulate the same feeling. Practise by coasting down a small hill, carving turns by swinging the bike back and forth beneath you.