What is the Toughest Olympic Sport?

Combining grueling cross-country skiing with shooting - No, it's not a scene from The Revenant, nor is it for the faint hearted, quite literally. It requires the athlete to be immune to the freezing cold, have perfect langlauf, cross-country skiing technique, the deadeye accuracy of a sniper, and a Zen-like ability to control his own heart rate. The seemingly unlikely pairing of skiing and shooting has been a Winter Olympic staple since 1960. But it might not surprise you to learn that before it was a sport, it was a Scandinavian survival skill. For this reason, it has long been used as a training exercise for soldiers.

In fact, the first known biathlon competition took place in 1767, when two Norwegian border control companies faced off against each other. Why haven't we got any footage? When it made its Winter Olympic debut in 1924, it was actually called military patrol. So how does it work? Biathletes strap a 22-calibre rifle to their backs and race around a trail. They must make a series of stops to shoot at a line of five metal targets 50 meters away from either a standing or a prone position. Each missed shot accrues a time penalty. So, hitting all the targets is a must. If you think the skiing part sounds tough, imagine shooting accurately whilst on the verge of fainting.

Most competitors spend less than 20 seconds at the range during a race, usually only taking a breath and a half between shots. But it's a delicate balance. Keep it in too long, and oxygen deprivation causes blurred vision. Let it out, and you waste valuable fractions of seconds resetting. Not only that, but the athletes have to remember to flex the large muscles in their legs or abdomen while they're lying on the mat to prevent blood from pooling. Otherwise, they would be at risk of fainting.

Now factor in the pounding of a fully exerted cardiovascular system. When gliding into the shooting range, their heart rates can reach 180 beats per minute. It sounds like a lot, but how does it measure up? The average human has a resting heart rate of between 80 and 100 beats per minute. A road cyclist will often experience a heart rate of 140 beats per minute. A swimmer may experience 165 beats per minute, as all major muscles are being used just to stay above water. To give you a sense of how fast that is, Flight of the Bumblebee is played at 172 beats per minute.

When your heart is going all guns blazing like this, even the pulse throbbing in your fingertips can cause microscopic flinching. Invisible to spectators, this can nevertheless affect accuracy. To compensate for hearing and feeling your own blood rushing around your body, biathletes often spend hours each week with a sports psychologist to learn to keep a clear head to compensate for a trembling hand. So how do athletes train for this, the most James Bond of Olympic disciplines?

Unsurprisingly, by skiing for miles and miles a day. And if there's no snow, there's no excuse. They use roller skates instead. The regime is so grueling that they have to eat 5,000 calories a day. That's twice the normal recommended daily intake. So, it was the toughest Olympic sport that was scrutinized with details from different aspects.