Is exercise dangerous? It seems so, with cases of young, healthy athletes collapsing suddenly and dying of cardiac arrest while playing sport becoming more common.
But a new study by researchers from the University of British Columbia in Canada suggests that while it is a problem that warrants attention, don't blame sport.
Reviewing coroners' reports, Dr Andrew Krahn and a team of researchers found there were 174 cases of presumed sudden death in Ontario, Canada in 2008, in people aged two to 40 years. Heart disease was present in about seven in 10 cases, 78 per cent of which was unrecognised. Most victims were male between the ages of 18 and 40.
Most events (72 per cent) occurred at home. Only one third of events involving children or adolescents and just 9 per cent of events in adults happened during moderate or vigorous exercise.
These findings dispel a myth that sudden cardiac death often takes place during rigorous physical activity. "Put it this way: if you have a 13-year-old kid who is not the star athlete who dies at home watching television, it doesn't make the news," says Krahn. "But if the same kid is a high-school quarterback or hockey star, then it's covered."
How can unrecognised heart disease be caught before it causes sudden death, particularly in young people?