Olympics-Biathlon-No swooning, just be still my beating heart

WHISTLER Feb 24 (Reuters) - "Be still my beating heart" is a plea usually associated with swooning romantics but it is probably much more apt for the biathletes battling for supremacy at the Vancouver Winter Olympics.

The gruelling endurance sport combines cross-country skiing with rifle shooting and the toughest challenge for competitors is being able to focus on fixed targets with a heart rate spiking at around 200 beats per minute.

"It's like if you had to run up 10 flights of stairs absolutely as fast as you could and then you had to thread a needle five times," Canadian Megan Imrie said of the tricky transition from freestyle skiing to shooting.

"You're trying to pair up a very fine motor skill with an extremely intense exercise, not to mention the mental side of knowing your competitors are shooting right beside you."

Imrie, who took up biathlon at the tender age of six, said the transition to prone shooting was much easier than for standing shooting.

"After two kilometres, my heart rate might be around 200 beats per minute but the lactic acid hasn't really got a huge chance to accumulate yet so prone can be okay," the 24-year-old told Reuters.

"But by the time you come to standing (shooting) after four kilometres, your legs are burning and your lungs are screaming at you.

SHAKING LEAF

"It becomes then a mental battle to shoot quickly and get those shots fired down the range before the lactic acid makes your muscles start shaking like a leaf."

Biathletes use a 5.6mm small-bore rifle with a custom-fit stock and they each fire at five fixed targets for every round of shooting, alternating between the prone and standing position.

For American Tim Burke, the transition from skiing to shooting is one of the most difficult challenges in any sport.

"You can't really slow down and you can't take too much time between each shot because the competitions are so close and you can win or lose in just one or two seconds," the 28-year-old told Reuters.

"So you have to become comfortable shooting with a really high heart rate when you're really uncomfortable and your body is gasping for air. It's something that's very unnatural.

"Your body wants as much oxygen as possible but you need to almost hold your breath a little bit, to pause, for each individual shot. It takes 10 years at least to become proficient at it."

Burke, who lies fourth in the World Cup individual standings this season, said getting every component right on the day was the Holy Grail of biathlon.

"You might have a good ski race and a good shooting race but you shot too slow," he said. "Or you might feel good while skiing but have bad skis.

"There are so many aspects that you need to have right on any given day and it's really hard to line all those things up in one race. That is what makes it so challenging." (Editing by Ed Osmond; To query or comment on this story email sportsfeedback@thomsonreuters.com)