When I was twice in the hospital in October and November for scary bouts of Fascicular Ventricular Tachycardia, a very rare condition, I asked the cardiologists: could running have caused this?
Although to my surprise they didn’t think running had anything to do with it, they didn’t endorse running either. There seems to be a consensus among cardiologists that endurance training may not be a good thing. One of them even even joked that they recommend a bit of physical activity but nothing more than that.
Is there such thing as Too Much Running?
While heart science has gone a long way in the last decades, there are still grey areas. Especially when it comes to understanding why young and seemingly healthy athletes develop heart conditions that can sometimes be life threatening.
One of the most prominent example is Emma Carney, two time World Triathlon Champion and World Triathlon Hall of Fame inductee. She was forced to retire from professional triathlon in 2004 after suffering a cardiac arrest. Her condition is one of a kind: she presented symptoms similar to Arrhythmogenic right ventricular dysplasia (ARVC), a normally hereditary heart disease, except that Carney didn’t show the usual genetic markers. This lead to a research article that suggested her condition was exercise induced rather than hereditary. In other words, years of intensive endurance training had damaged her heart.
In 2013, referencing multiple studies about the impact of running on mortality, James 0’Keefe MD wrote in the British Medical Association Journal – Heart: “Evidence is accumulating to indicate that exercise routines that are best for conferring Cardiovascular (CV) health and longevity are not identical to the fitness regimens that are best for developing maximal endurance and peak CV fitness. The potential for CV damage secondary to extreme endurance exercise appears to increase in middle age and beyond.”
What’s the sweet spot?
While researchers agree that excessive endurance training can negatively impact cardiovascular health, there’s a heated debate on the optimal amount of training to reap the maximum health benefits.
The famous and much-referenced Copenhagen City Heart Study (2013, 2015) suggested a U-shape association between all-cause mortality and running. In other words, beyond a certain point, excessive running does not provide any incremental health benefits. Even worse, the study found no statistically significant difference in mortality rate between strenuous runners and sedentary people. The Copenhagen City Heart Study highlighted the following running regimen as associated with the lowest mortality:
Copenhagen City Heart Study
Distance: 1 to 2.4 hours of running per week
Frequency: 2 to 3 times per week or 1 time per week
Pace: slow or average
Those conclusions are in line with this 2012 study by Duck-chul Lee et al. that found the following running program was best when it came to health benefits:
Duck-chul et al. 2012 study
Distance: up to 32 km (19.9 mi) per week
Frequency: 2 to 5 times
Pace: 5:19 to 6:12/km (8:34 to 10:00/mi)
Alternatively, Paul T. Williams, based on data from Runner’s World’s National Runners Health Study, concluded that there was ‘no point of diminishing return to the health benefits of running at any distance less than 80 km/week’.
Personally, while I would gladly accept Williams’ blank check, I’m convinced that my fascicular ventricular tachycardia condition has something to do with my marathon training. Therefore, I will most likely cap my runs to 30 km per week and continue practicing aikido and yoga. Indeed, as James O’Keefe explains, while exercising strenuously for a long time is not advised, there’s nothing wrong with adding lighter activities on top of it!
What do you think is the optimal amount of running or endurance training? Please share your thoughts in the comments.
On the photo: Meb Keflezighi, 2004 marathon Olympic silver medalist, and New York 2009 and Boston 2014 marathon winner.