You know how it is, you start preparing for a marathon or a long trail run and after a couple of training days you start pushing the limits. Even if you do not really have the physical base you feel this urge of running. It makes you feel good. And yes, it can be even addictive. So before you know it you are running 6 times a week for at least 10 km at a high pace. And of course, running is good for you. You get in shape, it gets your endorphins racing and you spend time outside. What can be bad about that? But is more really better? Would it have a negative impact on your heart as is often mentioned. Let's see what the scientists say.
In January 2019 the results of a long duration scientific study on the possible dangers of extreme exercise were published. (1). The Cooper Institute together with the Cooper Clinic and UT Southwestern Medical Center followed 21 758 healthy middle-aged men for a period of 10 years. At the start of the study each participant underwent a study on coronary artery calcification (CAC)*. Then the participants were divided into 3 groups, depending on their level of physical activity. Participants with the highest physical activity ran a distance of about 6 miles (10km) every day at a speed of about 10 min/mile or 6.2 min/km.
*The calcification of coronary arteries is a pathology in which calcium settles on the walls of blood vessels. Because of this, "plaques" are formed, which lead to serious cardiovascular diseases. Coronary calcium index can be measured using a special study.
The running paradox
The scientists discovered 2 contradictory facts.
Those athletes who run the most had also the highest probability of calcification of the coronary arteries. But at the same time the probability of the highest intensity athletes to die was lower than those we ran much less.
It turns out that if you run a lot, the risk of vascular calcification is higher than if you run a little, but such calcification does not lead to disease. The conclusion of the scientists: long running training will not make your health worse.
Why is this happening? One of the leaders of this study, Dr. Defina, suggested in the NY Times (2) "There is some evidence that the plaques" in highly active people "are denser and more stable" than those in sedentary people making them less likely to break free and cause a heart attack.
So, in conclusion, long runs do not really cause harm. Based on own experience I would however combine it with other forms of training. High intensity repeat training, strength training, low intensity recovery - all form part of a well-balanced training regime. We will work this further out in one of the next articles.
Founder and inspirational leader in G-Lab. The founder of the Gladiator Race — the most extreme obstacle race in Russia (11 races, 10 000 participants). Crossfit level 1 coach. Karathe and Muay Thai awards winner. Australian amateur football championship participant. A lifelong athlete since 8 years old.