PEOPLE who take nutritional supplements such as protein shakes are more likely to engage in doping.

As sport administrators, players and politicians come to grips with the impact of illegal drug use in sport, anti-doping scholar at the University of New South Wales Jason Mazanov said there was as much reason to be concerned about the prevalence of legal performance-enhancing products.

Peter Larkins.

Overseas studies indicate a relationship between legal supplements and illegal performance-enhancing drugs.

A 2006 study published in the European Journal of Epidemiology found non-professional athletes who took nutritional supplements were four times more likely to engage in doping and seven times more likely to participate if their friends doped.