When i did my medical for NATS before joining I had to do what they refereed to as the extended medical, it consisted of first blowing into respersitory machine taking measurement of lung capacity and flow I think, then stepping on and off a box about 20inches high 100times with a constant rhythm (sounds harder than it is, after about 70steps
plus i'm fairly tall, but if shorter in the leg department imagine it would be even harder) taking a measurement then and after 10mins to see how quickly i recovered from the exercise, I passed but I only have mild asthma and don't smoke.
HTH.