Natural sporting ability and predisposition to cardiovascular disorders

Abstract

We tested the hypothesis that people with a natural ability in 'power sports' (a presumed marker for predominance of type 2, glycolytic muscle fibres) might have increased risks of coronary heart disease (CHD) compared to those with a natural ability in 'endurance sports' (as a marker for predominance of type 1, oxidative muscle fibres). We examined subsequent cardiovascular disorders retrospectively in 231 male former soldiers, aged 34-87 years, who had undergone a course in physical training in the Army School of Physical Training, Aldershot, UK, who assessed themselves as having natural ability in either power (n = 107) or endurance (n = 124) sports. The proportion with CHD, defined as angina and/or coronary angioplasty and/or coronary artery bypass graft and/or heart attack was 18.7% in the 'power group' vs. 9.7% in the 'endurance group' (difference: χ2 = 3.9, p = 0.05). The proportions with CHD and/or risk factors rose to 39.3% in the 'power group' vs. 25.8% in the 'endurance group' (difference: χ2 = 4.8, p = 0.03). Under logistic regression analysis, compared to the 'endurance group', the 'power group' had 2.2 (95% CI: 1.00-4.63) the risk of developing CHD, and 1.86 (95% confidence interval: 1.06 to 3.25) the risk of developing CHD and/or risk factors. Men with a natural ability in 'power sports' are at increased risk of developing cardiovascular disorders, compared to men with a natural ability in 'endurance sports'. A predominance of type 2, glycolytic muscle fibres, presumably of genetic origin, may predispose to cardiovascular disorders.