Is endurance training the secret to health and longevity, or is it actually killing us? Depending on who you ask, endurance exercise is either the healthiest activity you can do or a fast track to heart damage and an early death.
The truth is far less dramatic.
While a few studies have identified specific risks in some elite endurance athletes, the overwhelming body of evidence shows that regular endurance training improves cardiovascular health, reduces disease risk, and helps people live longer. Here’s what the research actually says.
Key Points You Need To Know!
Endurance running is believed to be a primary driver in the evolution of humans
In general, endurance training decreases mortality, and endurance athletes live longer
While a greater incidence of arterial fibrillation is seen in high-volume endurance athletes, it does not appear to cause a meaningful decrease in health
Any single risk factor that may occur is outweighed by the plethora of positive health benefits
Are Humans The Greatest Endurance Animals?
Anthropologists and researchers largely believe that humans are the greatest endurance animals on the planet. More importantly, it’s largely agreed upon that endurance running played a central role in our evolution.
Some quotes from Bramble & Lieberman 2004 research state:
“Humans perform remarkably well at endurance running, thanks to a diverse array of features”
“The fossil evidence…suggests that endurance running is a derived capability of the genus Homo…and may have been instrumental in the evolution of the human body form”
“The development of endurance capabilities in Homo appears to parallel the evolutionary increase in brain size, cognitive sophistication, and metabolic rate.”
“Evidence for improved endurance begins to appear then too, and the growing consensus is that sustained physical activity, including distance running, was important in the development of hunting and gathering ecology”
It’s hard to suggest endurance training is harmful to humans, and our bodies literally evolved for it.
6 Human Adaptations For Endurance Running
While we may not realize it, especially people who hate endurance sports, our bodies were built for it. Here are some of the biggest biological adaptations endurance running is believed to have caused (Carrier, 1984; Bramble & Lieberman, 2004).
Eccrine Sweat Glands: Millions of sweat glands produce watery sweat across the entire body for rapid evaporative cooling while running.
Loss of Body Hair: Bare skin maximizes airflow and speeds up sweat evaporation to prevent overheating during prolonged exertion.
Bipedal Foot Structure: Large heels absorb heavy impacts while high, elastic arches act as natural springs.
Enormous Gluteus Maximus: Massive buttock muscles stabilize the trunk. They fire forcefully while running, but remain mostly inactive while walking.
Nuchal Ligament: A specialized neck ligament connecting the head to the spine to reduce bobbing while moving fast.
Achilles Tendon: Long, thick tendons that store mechanical energy when the foot lands and then release it to propel the body forward efficiently.
Does Endurance Training Increase Heart Complications?
A common claim is that endurance training increases heart complications, specifically arterial fibrillation (AF). There is some truth to this claim, but it’s massively overblown and greatly misrepresented.
One study used to “prove” this is a large review that compared the incidence of AF in athletes with non-athletes.
Athletes had a higher risk of AF than non-athletes
It found a higher risk in mixed sports than endurance sports
Only one of the 14 studies looked specifically at running
Nordic skiing was the most common sport reviewed
Now, this doesn’t mean an increased risk is never seen in running and cycling. Yet when it does, it’s mostly seen in athletes with long-term, high-volume endurance exposure.
In other words, it’s not usually seen by people who run 10Ks, half marathons, or a single marathon a year. Further, the mechanisms aren’t entirely understood, so it’s still hard to even explain this correlation.
It’s also important to note that athletes as a whole had a higher incidence than non-athletes. However, it’s clear athletics builds a healthier body.
Using a single risk signal while ignoring all of the data on health benefits is dishonest.
A study that showed endurance athletes tend to live longer addressed the concern about higher AF and states (Garatachea et al., 2014):
“However, the studies analyzed here…do not support that such type of exercise is overall harmful to the human heart.”
“Recent data indicated 58% lower overall mortality and 57% lower CVD risk in a large cohort of participants in a 90-km cross-country ski race, by a rather mild increase in atrial fibrillation risk (hazard ratio, 1.2).”
“Veteran athletes with arrhythmias have higher heart rate variability, which has a cardio-protective effect.“
What all this means is there may be a specific AF risk signal in some long-term, high-volume endurance athletes. However, it doesn’t result in increased mortality, poor health, or decreased cardio. It’s actually the opposite.
Will Endurance Training Increase Mortality?
The truth is, endurance training will not increase mortality but rather decrease it. Numerous studies and reviews have made it clear that endurance athletes tend to live longer.
1. Reduced Mortality in Former Elite Endurance Athletes (Ruiz, 2014)
“Recent data from prospective cohort studies conducted on marathon runners, professional cyclists, and Olympic athletes indicate, however, that regular intense endurance-exercise training has protective benefits against cardiovascular disease and premature death“
2. Health Consequences of an Elite Sporting Career: Long-Term Detriment or Long-Term Gain? A Meta-Analysis of 165,000 Former Athletes (Runacres et al., 2021).
“Endurance and team sport athlete’s all-cause and CVD mortality was significantly lower than the general population”
3. Elite athletes live longer than the general population: a meta-analysis (Garatachea et al., 2014)
“Athletes, especially endurance athletes, had higher mean life expectancies than did controls; in addition, they had lower mortality rates owing to CVD than did controls.”
As you can see, when looking at actual outcomes, it’s clear that endurance training offers huge benefits to your health. This is especially true when you consider the volume the average runner or cyclist is doing.
Endurance training is good. Sprinting is good. Strength training is good…. It’s all good!
FAQ: Is Endurance Training Bad For Your Health?
Does endurance training increase your risk of heart disease?
No. Regular endurance training is consistently associated with lower rates of cardiovascular disease and premature death. While some veteran endurance athletes may have a slightly higher risk of atrial fibrillation (AF), the overall cardiovascular benefits greatly outweigh this specific risk.
Can running too much damage your heart?
For most people, no. Research suggests any increased AF risk is primarily seen in athletes with decades of high-volume endurance training, not recreational runners completing 5Ks, 10Ks, half marathons, or occasional marathons.
Do endurance athletes live longer than the general population?
In general, yes. Multiple large reviews have found that endurance athletes generally have lower all-cause mortality, lower cardiovascular mortality, and longer life expectancy than non-athletes. The evidence consistently supports endurance exercise as a longevity-promoting activity.
Are humans naturally built for endurance running?
Yes. Humans possess several adaptations that support endurance running, including abundant sweat glands, long Achilles tendons, large gluteal muscles, spring-like foot arches, a nuchal ligament for head stability, and efficient upright locomotion. Many anthropologists believe these adaptations were important during human evolution.
How much endurance training is needed for health benefits?
Most health benefits occur well before elite training volumes. Meeting physical activity guidelines with regular walking, jogging, cycling, swimming, or other aerobic exercise is enough to significantly improve cardiovascular health and reduce the risk of premature death, without requiring marathon-level training.
References
Bramble, D., Lieberman, D. Endurance running and the evolution of Homo. Nature 432, 345–352 (2004). https://doi.org/10.1038/nature03052
Carrier, D. R. (1984). The energetic paradox of human running and hominid evolution. Current Anthropology, 25(4), 483-495
Garatachea, N., Santos-Lozano, A., Sanchis-Gomar, F., Fiuza-Luces, C., Pareja-Galeano, H., Emanuele, E., & Lucia, A. (2014). Elite athletes live longer than the general population: a meta-analysis. Mayo Clinic proceedings, 89(9), 1195–1200. https://doi.org/10.1016/j.mayocp.2014.06.004
Newman, W., Parry-Williams, G., Wiles, J., Edwards, J., Hulbert, S., Kipourou, K., Papadakis, M., Sharma, R., & O’Driscoll, J. (2021). Risk of atrial fibrillation in athletes: a systematic review and meta-analysis. British journal of sports medicine, 55(21), 1233–1238. https://doi.org/10.1136/bjsports-2021-103994
Pontzer H. (2017). Economy and Endurance in Human Evolution. Current biology : CB, 27(12), R613–R621. https://doi.org/10.1016/j.cub.2017.05.031
Ruiz, J. R., Fiuza-Luces, C., Garatachea, N., & Lucia, A. (2014). Reduced mortality in former elite endurance athletes. International journal of sports physiology and performance, 9(6), 1046–1049. https://doi.org/10.1123/ijspp.2013-0492
Runacres, A., Mackintosh, K. A., & McNarry, M. A. (2021). Health Consequences of an Elite Sporting Career: Long-Term Detriment or Long-Term Gain? A Meta-Analysis of 165,000 Former Athletes. Sports medicine (Auckland, N.Z.), 51(2), 289–301. https://doi.org/10.1007/s40279-020-01379-5
