Current guidelines recommend that every adult achieves 30 minutes or more of moderate physical activity in leisure time, preferably every day of the week. A study conducted among cyclists in Copenhagen, Denmark suggests that it is the relative intensity – and not the duration – of activity (in this case, cycling), which is of most importance in relation to all-cause mortality and, specifically – coronary heart disease mortality. P Schnohr, from Bispebjerg University Hospital (Denmark), and colleagues assessed 5,106 healthy men and women, ages 21 to 90 years, among the general population of Copenhagen, Denmark, and followed them for an average of 18 years. The total number of deaths during follow-up was 1,172, of which 146 were due to coronary heart disease. Among both sexes, the team found a significant inverse association between cycling intensity and risk of all-cause and coronary heart disease death, but only a week association to cycling duration. Men with fast intensity cycling survived 5.3 years longer, and men with average intensity 2.9 years longer than men with slow cycling intensity. For women the figures were 3.9 and 2.2 years longer, respectively.  Writing that: “Our findings indicate that the relative intensity and not the duration of cycling is of more importance in relation to all-cause and coronary heart disease mortality,” The team writes that: “Our general recommendations to all adults would be that brisk cycling is preferable to slow.”