The third trait, lactate turn point, is the percentage of VO2 max a runner can sustain before anaerobic respiration begins.

In addition to VO2 max, the second key characteristic is running 'economy,' meaning the body must use oxygen efficiently - both internally and through an effective running action. 'This means they meet their entire energy needs aerobically (from oxygen) - rather than relying on anaerobic respiration, which depletes carbohydrate stores in the muscles and leads to more rapid fatigue.' 'To run for two hours at this speed, athletes must maintain what we call 'steady-state' VO2,' Professor Jones said. The runners in the study included Eliud Kipchoge, who took part in Breaking2 - falling just short of the two-hour target - but later achieving the goal in 1:59:40.2 in the Ineos 1:59 challenge.īased on outdoor running tests on 16 athletes in the selection stage of Breaking2, the study found that a 59kg runner would need to take in about four litres of oxygen per minute (or 67ml per kg of weight per minute) to maintain two-hour marathon pace (21.1 km/h).

'The requirements of a two-hour marathon have been extensively debated, but the actual physiological demands have never been reported before.' 'Instead, what we see in the physiology of these runners is a perfect balance of characteristics for marathon performance. 'Some of the results - particularly the VO2 max - were not actually as high as we expected,' Professor Jones said. The VO2 measured among elite runners shows they can take in oxygen twice as fast at marathon pace as a 'normal' person of the same age could while sprinting flat-out. Professor Andrew Jones, of the University of Exeter, said the findings reveal that elite marathon runners must have a 'perfect balance' of VO2 max (rate of oxygen uptake), efficiency of movement and a high 'lactate turn point' (above which the body experiences more fatigue). The study is based on detailed testing of athletes who took part in Nike's Breaking2 project - an ambitious bid to break the two-hour barrier.

Download 2 hour marathon