Skiing through snow with a rifle across the back might sound more like a hunting expedition than a sport.
But biathlon requires just as much skill and application as the other Winter Olympic disciplines.
Competitors need technique and stamina in abundance as they cross-country ski for up to 20km.
And they must also be able to lower their heart rate enough to hold the gun steady as they aim at a tiny target - with the threat of extra distance to ski or time penalties if they miss.
HOW THE COMPETITION UNFOLDS
Skiers set off a regular intervals and race against the clock as they aim to complete an undulating course as fast as possible.
The race is made up of laps, like in athletics, and competitors must stop at the shooting range on each circuit to fire at a target.
Here they take five shots using a small-bore rifle without magnifying sights, with either time or distance penalties being added for each target missed.
The skier must come to a complete stop before they start firing and two different positions are used.
From the ground: The shooter must fire five shots at a 45mm target from 50m away. The shooter's elbow can touch the surface but the wrist must not.
Standing up: The shooter fires five shots at a 115mm target from 50m away.
Athletes will often slow down before they reach the shooting station in order to control the heart rate and relax the body.
Each event has a different set of shooting and penalty rules:
Individual - men's 20km; women's 15km
Each entrant has four sets of five shots - alternating between shooting from ground and standing up - on each 5km lap.
An extra minute is added to each racer's time for every target missed.
Sprint - men's 10km; women's 7.5km
Skiers must complete two laps of the course with five shots at the target after each lap, one set standing up, the other shooting from the ground.
For each target missed, an additional 150m is added to the athlete's circuit.
Pursuit - men's 12.5km; women's 10km
This event involves the top 60 qualifiers from qualifying heats. The qualifier with the best score in the shooting is the first to go, and the rest set off in pursuit at intervals determined by their qualifying performance.
There are four laps and shooting sessions, two standing and two from the ground.
Relay - men's 4x7.5km; women's 4x6km
Each team has four skiers. Each member must complete the distance and take two sets of shots at five targets, one from the ground and the other standing.
Mass start - men's 15km; women's 12.5km
Introduced in 2006, this event sees the 30 best-ranked competitors start together.
The men must complete 15km - five circuits of 3km - while the women must complete 12.5km - five circuits of 2.5km.
A set of five shots must be fired after each circuit, the first two sets from the ground and the last two standing.
A penalty circuit must be completed for each target missed.
Biathletes generally use the same equipment as cross-country skiers - with the obvious addition of a rifle on their backs.
However, biathletes prefer to use a skate-style ski, which requires a grooved track, because they generate more speed.
The rifles must be able to shoot in sub-zero temperatures.
WANT TO GET INVOLVED?
The British Biathlon Union (BBU) is the sport's governing body in Britain.
But it does not receive funding from UK Sport or the National Lottery, so biathletes often have to fund their training themselves.
The website contains all the information you need to get started.
The International Biathlon Union is the sport's governing body.