All cyclists know that fitness is lost after an extended break – for example when injury strikes. But what happens to the body when you stop training for 14 years?!



More specifically, what happens to the physiology and physical fitness of a cycling legend such as Miguel Indurain. Is his body subject to the normal age and fitness-related declines in performance that us mere mortals would expect to suffer or could his unique genetics help resist the normal laws of exercise physiology?



That’s the question that Spanish researchers have been able to answer in a recently published study on no less than the great man himself.



The science

In the study, scientists from the USP Araba Sport Clinic in Spain sought to gain some insight into the aging and detraining process of elite cyclists. In order to do this, they studied the 5-time Tour de France winner and Olympic Champion Miguel Indurain some 14 years after retirement from professional cycling.



During his racing years, Indurain’s stats made mightily impressive reading: His heart/lung system enabled him to transport around 7 litres of oxygen around his body per minute, compared to 3-4 litres for an ordinary person and 5-6 litres for fellow riders.



His maximum cardiac output was measured at 50 litres a minute (a fit amateur cyclist’s is about 25 litres per minute) while his maximum oxygen uptake capacity was reputed to be around 88ml/kg/min – in comparison, Lance Armstrong’s was ‘only’ 83.8 ml/kg/min! The actual test was very straightforward; Indurain visited the lab and performed a progressive cycle ergometer test to exhaustion during which a number of physiological measurements were made.



The results

Inevitably, some 14 years after retiring, Indurain’s stats were not quite so mind boggling. Now aged 46, his body mass had increased from around 80kg in his competitive years to 92.2kgs and his maximum oxygen transport capacity had fallen to 5.3 litres per minute.



Meanwhile his maximum oxygen uptake capacity had also declined to 57.4 ml/kg/min.



However, these results are still respectable by many cyclists’ standards and when the researchers measured his cycling performance at lactate threshold (the steady intensity that can be sustained before lactate begins to accumulate and fatigue sets in) they found that he was able to transport 4.28 litres of oxygen per minute (that’s equivalent to an oxygen uptake of 46.4ml/kg/min) and sustain a very healthy power output of 329 watts while all the time, his blood lactate concentration remained below 2.4mM.



To put this into perspective, these are kinds of figures that many amateur cyclists in continuous hard training would struggle to match! It was also clear that while age and inactivity-related declines had taken their toll, Indurain’s increase in body mass had an even bigger effect on his drop in fitness. To put it another way, had he gained less weight during those 14 years of retirement, his stats would have been even more impressive!



So what?

What do these results tell us? Well firstly, it doesn’t matter who you are – if you stop training, you will lose fitness. They also indicate that aging plays a significant role in the decline of fitness over the years.



However, they are also encouraging because while Indurain is undoubtedly blessed with superior cycling genetics (and perhaps maintained more fitness than would be expected in lesser cyclists), they suggest that the bulk of his fitness loss was due to inactivity and weight gain rather than aging per se. In short, if you keep the pounds off and stay active, you could make a cycling comeback more easily than you thought!



Int J Sports Physiol Perform. 2012 Aug 1. [Epub ahead of print]



This article was first published in the October 25 issue of Cycling Weekly. You can also read our magazines on Zinio and download from the Apple store.