I haven’t been to the gym for two weeks, but it’s fine: I just need to watch sport on television. A study from the University of Montreal has found that watching ice hockey substantially increases your heart rate. For television-watchers, the increase was an average 75%, while for those watching live it rose by 110%. This is equivalent, say the researchers, to moderate and vigorous exercise respectively. Heart rates were highest during overtime and if there were scoring chances.

The solution

As with all research, you have to ask if the results are applicable to people outside of the study. In this case, maybe not – not everyone finds ice hockey exciting, after all.

However, there is other research showing that watching football can stress the heart so much that it triggers strokes and heart attacks. A study of German fans compared heart rates and blood pressure as they watched their country play in the 2006 World Cup. Both heart rate and blood pressure were raised – thought to be due to adrenaline release – when they watched their own team, and stayed higher for hours afterwards.

The Canadian study (which claims to be the first to measure the pulses of people watching an ice hockey game) was prompted by an observation made by 13-year-old Leia Khairy, daughter of Prof Paul Khairy, the lead researcher. She noticed that while her own heart was pumping as she played soccer, the parents on the sidelines were jumping up and down even more energetically.

But Khairy is very clear: “Watching an ice hockey game is not a substitute for physical activity. It raises heart rate (and likely also increases blood pressure, although this was not measured in our study) but does not carry the same benefits on cardiovascular health as exercise.”

There is also no weight-bearing among spectators, apart from the occasional leaping from a seat – so muscles are not being exercised. More of a worry is that watching sport causes emotional stress, which research shows can trigger heart attacks in people who already have underlying heart disease. In this respect, watching ice hockey joins other known triggers for cardiovascular events such as hot weather, holidays, earthquakes, sex and cocaine use.

The study of German football fans found that a stressful match more than doubled the risk of a heart attack or a stroke. So it may be that you need to be fit before you watch a sporting event, rather than hope it is the equivalent of a short burst of exercise. Studies have only shown a significant effect on men, and there is no correlation between a fan’s emotional connection with a team and the triggering of a heart attack. The authors of the Canadian paper suggest that anyone watching an exciting game should take seriously any symptoms such as chest pain or shortness of breath.