Taking a deep breath in isn't an instruction you'd normally want to follow on Oxford Street. Fortunately John Lewis's pop-up rooftop garden is a world away from the bustle and fumes of the oavements below, and makes a rather spectacular venue for Fat Buddha's weekly morning yoga class. You'll have to set your alarm clock; the 7.30am start time allows you to get to the office on time afterwards but it's a challenge for serial snoozers. But stretching your limbs into the early morning sunshine as bees visit the flowers around you is totally worth the wake up call. Mats are provided and the class is suitable for beginners, with suggestions for more advanced moves dropped in every now and then. You'll arrive yawning and leave beaming.