It seemed to me one of the strangest coincidences of all time: two chess players dying on the same day at the end of the biennial Chess Olympiad in Norway. But when I spoke to a chess-playing friend of mine, he said “Is it really so odd?” There were almost 2,000 players taking part in the event, quite a few of them – especially the men – getting on in years, unfit, sedentary. Healthwise, they were high risk. Are two deaths really so surprising?

My friend is right and wrong at the same time. It is a bizarre coincidence that two players – one from the Seychelles, one from Uzbekistan, the former at the board, the latter in his hotel room after the tournament had ended – should die within hours of each other. That’s why there has been news interest in the case, and why he is wrong in this respect. But he is spot on about the susceptibility of chess players to stress-related conditions. Chess, though the non-player might not believe this, is in many ways an extreme sport.

At the Olympiad, participants were playing a game a day over a fortnight – 11 rounds with just a couple of rest days on which to recuperate. For up to seven hours a day, they would be sitting at the board trying to kill – metaphorically speaking – their opponent, because this is the ultimate game of kill or be killed. In some positions, you can reach a point where both sides are simultaneously within a single move of checkmating the other. One false step and you will have lost. This imposes enormous pressure on players.

These days, some top players use psychologists to help them deal with this stress. They are also paying increasing attention to diet and fitness. I was staying in the same hotel as many of the world’s top players during the great annual tournament at Wijk aan Zee on the Dutch coast in January, and was struck by the regime adopted by Levon Aronian, the Armenian-born world number two, who started each day with a run followed by a healthy breakfast.

These elite players, however, are the exception within the chess world: they have the money and the specialist entourage that allows them to put a high priority on fitness and well-being. They realise that to play top-level chess, you have to be extremely fit and mentally settled. Any physical ailment or mental distraction is likely to stop you playing well. You need to be at the top of your game to perform. In that sense, it is as much a sport as football or rugby; indeed, it has been suggested that in the course of a long chess game a player will lose as much weight as he does during a football match.

Outside the elite – among professional players who are struggling to make a living, or among the hordes of us middle-aged blokes trying to get to grips with this stressful, frustrating, exhausting game – there is far less attention paid to health. Chess clubs often meet in pubs and many players like a pint; the number of huge stomachs on show at any chess tournament is staggering. The game – and I realise this is a wild generalisation, but one based on more than a grain of truth – tends to attract dysfunctional men with peculiar home lives. You can bet their diet will not be balanced; many will be living on bacon and eggs and beer. This is not a recipe for a long, healthy life.

The great Soviet players of the postwar period had the most ridiculous lifestyle: they more or less lived on vodka, cigarettes and chess, and many of them died young. Take Leonid Stein as an example. A three-times champion of the USSR in the 1960s, he dropped dead of a heart attack in 1973 at the age of just 38. Mikhail Tal, world champion in the early 1960s, was dogged by ill health during his career, and died at the age of 55 – a desperate loss to the sport. Vladimir Bagirov, who was world senior champion in 1998, was 63 when he dropped dead at the board while playing in Finland in 2000.

The current crop of top players have learned from the mistakes of their Soviet predecessors, but those outside the world elite haven’t. Too many are overweight, keen to have a drink, too sedentary – and then they try to play this game which makes huge demands on mind and body. I know, because I do it too. I spend a day at work, rush home, bolt down a meal, then go to my chess club and play a three-hour game which often makes me feel ill, especially if I lose. After that, usually around 10.30pm, I go home, go to bed, and frequently fail to sleep as my moves and mistakes revolve around my head.

So next time someone suggests a nice, quiet game of chess, or paints it as an intellectual pursuit played by wimps, tell them they’ve got it all wrong: this is a fight to the finish played in the tensest of circumstances by two players who are physically and mentally living on the edge. We all need to get fitter to play this demanding game, and society should recognise it for what it is – a sport as challenging, dramatic and exciting as any other. Such recognition would be a tribute of sorts to the two players who sadly played their final games in Tromso.