A study in the Canadian Journal of Cardiology found that people's pulses increased by 75% when they watched a hockey game on television, and by 110% when watching a match in person – equivalent to the cardiac stress of vigorous exercise.
A 2008 study in the New England Journal of Medicine concluded that "viewing a stressful soccer match more than doubles the risk of an acute cardiovascular event".
So, if you are a sedentary sports fan not used to intense physical exertion, some worrying questions might just have sprung to mind about the implications for your own heart health. We shed some light and provide some answers.
If you have additional health concerns, speak to a doctor.
A study from China presented at a recent American Heart Association meeting showed that men who had suffered heart attacks were more likely to show signs of reduced blood flow to the heart (ischaemia) and activated blood clotting when they were watching exciting Olympic events as opposed to other entertainment programmes.
Spikes in heart attack rates have been seen in soccer fans after World Cup matches or penalty shoot-outs. A study of 4,279 German patients found that during 6 of Germany's 7 World Cup matches in 2006, there was a dramatic spike in reported heart problems than at the same time in previous years.
An analysis of a large study of hospital admissions in the UK discovered similar findings with an alarming spike in admissions on the day England was eliminated from the 1998 World Cup by Argentina and on the 2 subsequent days.
Researchers concluded that while an ordinary soccer game might not be dangerous, a heart attack "can be triggered by emotional upset, such as watching your football team lose an important match."
There is also evidence that the cause of such spikes cannot be conclusively linked to the stress of the game. Lack of sleep, drinking to excess, and forgetting to take prescribed medication while being distracted by the game, could all be contributing factors. It's also more likely to occur in people who already have existing heart conditions.
In addition, an Italian doctor pointed out that an increased intake of saturated fat from foods like fries, pork, lard and beef fat are commonplace among people who watch sports. Such food can trigger acute heart symptoms, especially when paired with things like stress and smoking.
A University of Michigan doctor also found that the heart attacks occurred during the World Cup were events that were about to happen very soon anyway.
The conclusion here is that while the added stress on the emotions of watching an important game can stress the heart, it is likely that the lifestyle of the individual as a whole is the main contributing factor. The game is just one of many possible triggers on an already stressed heart.
Don't put off calling for help if you feel chest pain or feel short of breath during the match – it's more important to seek medical attention than it is to watch the end of the game.
Maintaining a heart-healthy lifestyle will also help your prognosis in the long term so ensure that you follow your doctor's advice on diet and exercise.
The good news is that your chances of having a heart attack due to increased stress during a game are small if you have no pre-existing heart conditions. However, some risk factors, like high blood pressure or high cholesterol levels, may come with no symptoms. In other words, you may have a heart condition and not even know about it.
Be sure to have regular check-ups and heart screening as a preventive measure as these will flag any health concerns early enough to be treated and ensure that you remain in tip-top health for many more World Cups to come.