A spate of deaths during sporting activities - at grassroots and elite level - in recent months has left some wondering if the dangers of participating in sport have increased.
Cricket was shocked by the death of Australian batsman Phillip Hughes last year after he was struck behind the ear by a ball.
And there have been a number of other tragic losses, in rugby league, rugby union and football, since then - some from head injuries and others from heart failure.
So is sport getting more dangerous?
Statistics tell us very little. Up until now, there has been no detailed data on the number or nature of sport injuries treated by GPs or in hospitals.
All we know is that sports injuries accounted for roughly 2% of cases seen in emergency departments last year, according to figures from the Health and Social Care Information Centre.
But not everyone is asked how they were injured and the answer is not always noted down, so the total is likely to be much higher.
Allyson Pollock, professor of public health research at Barts and the London School of Medicine, says this has to change.
"We need to know the mechanisms of what's causing these injuries for all sports so we can assess the risks," she says.
Rugby union is one sport in which injuries, and particularly concussion, have been well monitored. Last season, in a study of nearly 600 rugby players in England, 13% experienced concussion - the most common rugby injury for the past three years.
As a result, concussion in rugby is now being taken seriously, but the risks are still there because of how the game is played.
Professional rugby players are now much bigger and heavier than they were, and they play a more aggressive form of rugby.
Prof Pollock believes this style of rugby is filtering down to young people and children playing the game, making it more dangerous.
"If other sports and young amateurs are mimicking the professional game, there's no reason to think we are not seeing the same thing at those levels."
To reduce the risk of serious injury in schools, she advocates taking contact out of collision sports such as rugby and football.
To some this might seem extreme, but she says "all games have evolved over time and we just need to make it safer for children and prevent injuries from happening".
Some sports are inherently more dangerous than others.
Snow sports, American football, equestrian sport and sky diving are all more risky than tennis, badminton and athletics, but that doesn't stop people from doing them.
In fact, more people are taking part in extreme sports such as base jumping and parachuting than ever before.
Dr Mike Loosemore, lead sports physician for the English Institute of Sport, says there is a definite trend towards trying out new and ever more dangerous activities, even though people are not always trained or equipped for them.
In an over-protective society, he suggests, it's one way of getting the adrenaline rush we all crave.
And adding lots of protective equipment isn't a solution to the increased danger.
"Padding just means you get braver. American footballers have massive, well-designed helmets but they don't stop concussion. Instead they use them as a weapon."
He says professional rugby players who wear shoulder pads just end up tackling harder.
In general, most sporting bodies are aware of the risks faced by those who take part and try hard to protect them by amending the rules and introducing new policies on injuries.
At an elite level, pushing the body harder and harder does make injuries more likely, but there will always be the risk of a freak accident or an undetected heart condition.
Thanks to round-the-clock media coverage we are all more aware of fatal injuries in sport when they occur too, which makes them feel more frequent.
At a basic level, sport is attractive because there is some danger involved. Taking that away altogether would change it completely.
Dr Loosemore says removing the risk is dangerous in itself.
"Sport is a way of putting danger into lives in a controlled way. If you get in a certain position it hurts.
"Sports that allow you to show courage are a good thing too.
"You don't want children to get hurt of course, but there is less chance of it happening if they play sport in the real world."