Tour de France Cyclists Live Longer Than Ordinary French Men

September 03, 2013

AMSTERDAM — Elite French cyclists participating in the Tour de France over the past 60 years have a significantly lower rate of mortality than French men in the general population, according to the results of a new study [1].

In evaluating the overall mortality rates of French cyclists who rode in the prestigious event between 1947 and 2012, investigators found the cyclists had a 41% lower mortality rate than men in France and that this lower mortality rate was consistent over time, including periods of reported heavy performance-enhancing-drug use. The lower rate was significant for deaths resulting from cancer and cardiovascular causes, and while it wasn't statistically significant for other causes of death, the mortality trends all favored the cyclists.

Presenting the results here today at the European Society of Cardiology (ESC) 2013 Congress, senior investigator Dr Xavier Jouven (Paris Descartes University, France) said that among the cyclists who rode in the Tour de France from 1947 to 1951, a period accounting for more than 60% of the deaths in the analysis, the elite athletes lived six years longer than men in the general population.

Jouven said the results, which are published concurrently in the European Heart Journal to coincide with the ESC hot-line session, back up his belief that the general population can benefit from exercise that goes beyond a mild walk in the park.

"There have been many concerns about elite athletes, but also concerns for the general population, including Sunday joggers," Jouven told heartwire . "Usually, we observe a slight increase in creatinine levels, a slight increase in troponin, or a slight increase in potassium. Studies have been suggesting it might be dangerous to exercise, to do marathons, and in one way it's true, but for a very small group of selected patients. In my mind, the overall message of harm, that doing sport is dangerous and that it's better to not do sport, is wrong."

While physicians must address the needs of their patients, including those with coronary artery disease and those who might be at risk for sudden cardiac death, the overall message for the general population is that the lifelong benefits of exercise, including high-intensity endurance sports, outweigh any potential risks when it comes to all-cause mortality, said Jouven.

"We need to balance our message and maybe start encouraging people to participate in sports, maybe even at a higher level than we are advising them," he told heartwire .

Results Consistent Across the Different Race Eras

Of the 786 French cyclists who rode in the tour since 1947, 208 have died. Of these, 59 cyclists died from cancer, mainly neoplasms of the digestive tract, lung, and prostate, a number that is 44% lower than what would be expected if the cyclists had the same mortality rate as the general male population. Similarly, deaths from cardiovascular causes were reported in 53 cyclists, a 33% lower rate than what would be expected based on estimates in the general male population.

Overall, the cyclists had a higher risk of death related to external causes, although this trend did not reach statistical significance when compared with French men in the general population.

Standardized Mortality Ratio by Causes of Death

Mortality Standardized mortality ratio (95% CI)
Death from all causes 0.59 (0.51–0.68)
Death from neoplasms 0.56 (0.42–0.72)
Death from cardiovascular diseases 0.67 (0.50–0.88)

Speaking with the media, Jouven said they tracked only French cyclists because they were able to ascertain the cause of death from the French healthcare system

The researchers said they were surprised by the findings, with Jouven saying he had expected to see a downside to such elite training and racing. However, that does not appear to be the case. He cautioned that the Tour de France riders represent a highly selected population. In addition, it can't be stated definitively that the physical fitness arising from their years on tour is the reason for their lower mortality rates.

Speaking during the hot-line session, Dr Sanjay Sharma (St George's University, London, UK), who was not affiliated with the analysis, said that exercising 40 METs per week, broken up over five or six days, reduces the risk of cardiovascular disease by 40% to 50%. Endurance athletes like those in the Tour de France exercise at intensities 10- to 20-fold greater than this, however. Regarding the potential deleterious effects, Sharma said studies have shown marathon runners with high circulating markers of cardiac damage, animal studies have suggested increased fibrosis and inflammation in the myocardium, and recent cardiac MR studies have shown increased fibrosis in veteran athletes.

It is the comparator arm, however, that Sharma took exception to in the French analysis. He said it is a comparison between "possibly the fittest human beings in the world, people that are physically, genetically, physiologically, and psychologically superior" and ordinary men. Among the general population, there is a much higher burden of comorbidities, risk factors for cardiovascular disease, and adverse lifestyles.

Sharma said the study shows that "if you are capable of doing the Tour de France, you might live six to seven years longer than the average individual in the community."

Dr John Mandrola (Baptist Health Louisville, KY), an electrophysiologist who writes a column for theheart.org and who is a competitive master's-level cyclist, said he was not surprised the tour riders live longer because they're genetically gifted athletes who compete and race in their peak years. However, they typically stop training once their career is finished. This contrasts with the master's-level athletes electrophysiologists treat, those who have exercised at high levels their whole life and who continue to train.

"The potential harm of exercise, like arrhythmias and fibrosis, seem to correlate with the cumulative effects over years," he told heartwire . "So, I guess the take-home message is that the effect of transient inflammation is different from long-term inflammation."

So, the Drugs Won't Kill You Then?

Speaking with heartwire , Dr Alfred Bove (Temple University, Philadelphia, PA), a past president of the American College of Cardiology who competes in triathlons and endurance running events, addressed the performance-enhancing-drug aspect of the tour, saying that whatever these athletes might have taken over the years to gain that critical edge, it didn't shorten their life.

"Now, there are some dangerous doping drugs, adrenalinelike doping drugs," said Bove. "There are some potent heart stimulants. but most of the cyclists, to my understanding, dope with [erythropoietin] EPO to build their red blood cell mass. If you build your red blood cell volume at the right time you can perform better, but from this standpoint, whatever they're doing, it's not doing any long-term harm."

Overall, Bove said the details of the study are difficult to interpret, so caution should be exercised about making conclusions. He said, however, that in the present era of sensitive testing, which includes biomarker assessments, ECGs, MRIs, and CT scans, first emerged in patients with heart disease.

"We do these tests in a sick hospital population, but when we take this information and try to apply it to a normal athletic population, it doesn't cross over properly," said Bove. As a result, ECGs and other sensitive tests are being read as abnormal when in fact the results might simply highlight the differences with an athlete's heart. "We don't have the details, but a lot of the Tour de France guys would have these abnormalities, and it's not causing a shortening of their life. It's an important piece of information."

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