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Vasalopp skiers run half the risk of having heart attacks

19 October 2015

Common endemic diseases can be prevented by exercise. This has been found in a new thesis to be presented at Uppsala University. The thesis author Ulf Hållmarker is an experienced competition doctor for the long-distance ski race Vasaloppet. His research has shown that physically active people with healthy lifestyles run only about half the risk of a first heart attack or stroke compared to the rest of the population.

‘Physical activity for about three hours a week, a healthy diet and not smoking  has a major effect on reducing cancer, heart attacks and strokes,’ says chief consultant physician Ulf Hållmarker, a doctoral student at the Department of Medical Sciences who soon will be publicly defending his thesis.

In his thesis, he explains the effects of lifestyle and physical activities on contracting and surviving major endemic diseases such as heart attacks, strokes and cancer. Medical data from 200 000 Vasalopp skiers has been compared to that of 500 000 randomly selected members of the population. Swedish medical records allowed 12 000 cancer cases and 10 000 heart attack and stroke cases to be examined.

Physically active people with healthy lifestyles reduce their risk of a first heart attack or stroke by around 50 percent. For people from this group who do have a heart attack, the risk of death or another heart attack is 30 percent lower. The equivalent figure for a stroke is a 15 percent reduction.

One interesting observation is that well-trained people have a slightly increased risk of atrial fibrillation, which sometimes causes strokes. Despite this, however, Vasalopp skiers still have a lower risk of a first stroke and those who do have strokes have less serious ones. Strokes caused by atrial fibrillation are also less common among skiers.

One serious risk, but a rare one, is cardiac arrest brought on by strenuous sports. About one in every 50 000 Vasalopp skiers suffer from this. To put it another way, it occurs only two to three times per million hours of skiing or running. Cardiac arrest can be treated using CPR (cardiopulmonary resuscitation) and a defibrillator. ‘A high degree of readiness for such treatment is important since 25 percent of sufferers can be saved,’ says Ulf Hållmarker.

The risk of cardiac arrest, however, is far outweighed by the positive effects on health provided by exercise and a good lifestyle.

In one of the component studies, Ulf Hållmarker showed that physically active people have a 30 percent lower risk of developing any of the various lifestyle-associated cancer types. These include cancer of the colon, uterus, lungs, kidneys, gall bladder and pancreas. At the same time, this group had a higher proportion of people with skin cancer. The reason for this is that cross-country skiers spend more time outdoors.

Download the entire text of the thesis “Epidemiological Studies on Long Distance Cross-Country Skiers: Participants in the Vasaloppet 1955‑2010”. All of the component parts of the thesis have been published in scientific journals.

Ulf Hållmarker is a chief consultant physician at the Medical Clinic in Mora and for many years has been the competition doctor for the Vasaloppet ski race. He was previously head of medical services and then CEO of Dalarna County Council. He has also served as the chairman of the Swedish Society of Internal Medicine and a board member of SBU (the Swedish Agency for Health Technology Assessment and Assessment of Social Services). The epidemiological studies in the doctoral thesis on cross-country skiers will be presented and publicly defended at the hospital Akademiska sjukhuset in Uppsala on 22 October 2015. The co-authors are researchers from Uppsala, Dalarna, Stockholm and Umeå. The head tutor is Professor Stefan James, Chief consultant physician in cardiology and head of research at the Uppsala Clinical Research Center, UCR.