. If that sounds too strenuous, there are also two shorter races: the two lakes trail is a 22K event starting at Plagne Bellecote and climbing up to Dou du Plaz to join the 6000D course, while the Randoplagne is an 11K race that links the various high-altitude

– on foot. The trek up to Gorak Shep will help you to acclimatise to the lack of oxygen in the air before you begin the marathon on rough mountain trails. Despite an overall drop in altitude, the going is tough but as you head down to Namche Bazaar

brutal finishing stretch surprised a few regular participants. There are few flat stretches in Madrid so expect a hilly course, then add to that the highest altitude of any European capital city and breathing becomes just that little bit more difficult