BikeRadar's videographer Joe was invited by The Altitude Centre in London to test out the effects of training at altitude and discover what benefits this extreme form of training could have on his watts.
However, based in Bristol, a whopping 11 metres above sea level, there are few mountains, so the conditions were recreated using a hypoxic generator. This big grey box on wheels with a mask coming out of it restricts the level of breathable oxygen in the air to simulate riding at 2,750m / 9,022ft.
The six week test, which followed a training plan devised by cross-country world cup racer and experienced cycling coach Tom Bell, involved plenty of pain and suffering for Joe, and hopefully a meaningful improvement in his watts. Find out how he got on in the video above.