Eliud Kipchoge’s 1.59 marathon showed us it was possible, but now a new study published in the Journal of Applied Physiology has revealed the specific combination of physiological abilities required to have a chance of running a sub-two-hour marathon.
The research, conducted by Professor Andrew Jones at the University of Exeter was based on data from extensive testing of the athletes – including Kipchoge – who were involved in Nike’s Breaking2 project. The project culminated in Kipchoge missing the 2-hr barrier by a mere 26 seconds on the Monza F1 race track before he went on to his sublime 1:59:40.2 at the Ineos 1:59 challenge in Vienna last year.
‘The requirements of a two-hour marathon have been extensively debated, but the actual physiological demands have never been reported before,’ says Jones, who also worked extensively with Paula Radcliffe throughout her career and in the build up to her London Marathon World record.
According to Jones, the findings reveal that the world’s best marathon runners have a ‘perfect balance’ of three factors:
A high VO2 max (rate of oxygen supply to working muscles)
Excellent running economy (efficiency of movement)
A high lactate turn point (above which the body experiences more fatigue)
It’s the combination of these qualities, rather than one particular stellar reading, that is key according to Jones. ‘Some of the results – particularly the VO2 max – were not actually as high as we expected,’ says Jones. ‘Instead, what we see in the physiology of these runners is a perfect balance of characteristics for marathon performance.’
Running on air
Drilling down into the data, the individual numbers measured in Kipchoge and the other athletes were, of course, hugely impressive. The elite runners were shown to be capable of taking in oxygen twice as fast at the required marathon pace as an average person of the same age.
To maintain a two-hour marathon pace of 21.1 km/h, 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 run for two hours at this speed, athletes must maintain what we call 'steady-state' VO2,’ says Jones. ‘This means they meet their entire energy needs aerobically, rather than relying on anaerobic respiration which depletes carbohydrate stores in the muscles faster and leads to more rapid fatigue.’
The second key characteristic is running economy, which refers to how efficiently the body uses the oxygen it takes in – both internally and through an effective running action.
The third trait, known as ‘lactate turn point’, is the percentage of VO2 max a runner can sustain before anaerobic respiration begins. ‘If and when this happens, carbohydrates in the muscles are used at a high rate, rapidly depleting glycogen stores,’ Jones explains.
‘At this point – which many marathon runners may know as 'the wall' – the body has to switch to burning fat, which is less efficient and ultimately means the runner slows down.’
Of course, understanding the theory from the lab data is one thing, but putting into practice precisely in a marathon is an additional challenge. And this is another area where the elite runners were found to excel. ‘The runners we studied – 15 of the 16 from East Africa – seem to know intuitively how to run just below their 'critical speed', close to the 'lactate turn point' but never exceeding it,’ says Jones.
‘This is especially challenging because – even for elite runners – the turn point drops slightly over the course of a marathon, and it’s not possible to measure this in the lab. Having said that, we suspect that the very best runners in this group, especially Eliud Kipchoge, show remarkable fatigue resistance.’
You Might Also Like