The vastly different incidence and mortality rates from coronary heart disease (CHD) experienced by genetically similar groups which have migrated around the world have convinced many of us that CHD is clearly related to environmental factors.1 At the top of the list of environmental factors are diet and exercise and their products, obesity and diabetes. Yet mathematical reductionism has reduced the discussion on CHD prediction to age, sex, lipid profile, arterial blood pressure and cigarette smoking.2 The roles of diet, exercise, obesity and diabetes are factored out by this equation. As a consequence, lifestyle factors are frequently ignored or even forgotten in the prevention and treatment of heart disease.

Physical inactivity has long been recognised as a risk factor for developing and dying from CHD.3 4 The study by Stamatakis et al in this issue of Heart attempted to establish whether the …