If you drive from Banff up to Norquay Ski Resort in the summer, you may see biathlete Nathan Smith doing a full-out climb on his roller skis.

Smith will blitz a 300-metre elevation gain over four kilometres in about 20 minutes. It's the most gruelling part of Smith's off-season training, and also the most rewarding for the Calgarian.

That lung-buster helped elevate Smith from an athlete who almost quit to one who made Canadian biathlon history. The 30-year-old became the first Canadian man to win a world championship biathlon medal when he took silver in the 10k pursuit last year.

A few weeks after the world championships, Smith became the second Canadian man to win a World Cup race after Jean-Philippe Le Guellec in 2012.

Smith was at a crossroads after a rough 2012-13 season. If he was going to compete in the 2014 Winter Olympics in Sochi, Russia, Smith decided he needed to train differently.

Smith is an efficient shooter, but he wasn't a strong climber then.

"A lot of people don't like to work on what they're not good at because it's not fun not being good at something," Smith said. "I had to kind of take my medicine and do stuff that's really hard for me.

"I decided to make myself hurt and work on the stuff I wasn't so good at, uphill training."

So Smith started hammering the paved switchbacks up Norquay Drive.

"It's one of my favourite, but my least favourite training sessions," Smith said. "You definitely feel glad when you're finished.

"Some times you're feeling terrible and you're halfway up feeling 'I just can't do it today.' You've just got to put your head down and find a way."

Smith's suffer-fests yielded results in 2013-14. He went from outside the top 50 to top-20 in some races, including a pair of top-15 finishes in Sochi.

"I was like 'Wow, I didn't think I could do that. Let's see what else I can do,"' Smith said.

Rare World Cup competition in Canada

Smith and Canada's biathlon team will compete in World Cup races at home for the first time in over two decades Thursday to Sunday at Canmore Nordic Centre. All events will be streamed live on CBCSports.ca, beginning with the men's sprint on Thursday at 1 p.m. ET.

"It's really exciting because most of the time the biathlon circuit visits the same eight sites," Smith said. "This is the first time I'll get to race here at a World Cup level. I've been training here since I was 10."

Racing starts with the men's 10k Thursday followed by Friday's women's sprint at the Nordic Centre. The men's and women's mass starts are Saturday and racing concludes with Sunday's mixed relays.

Rosanna Crawford and Macx Davies of Canmore, Calgary brothers Christian and Scott Gow, Brendan Green of Hay River, N.W.T., Julia Ransom of Kelowna, B.C., three-time Olympian Zina Kocher of Red Deer, Alta., and Sarah Beaudry and Megan Tandy of Prince George, B.C., join Smith on the host squad.

Smith is ranked 18th in the world with his best result so far this season a sixth in Ruhpolding, Germany, in January. He and Crawford won a mixed relay silver medal in November's season-opening World Cup in Sweden.

Smith's recent success is a confluence of hard work, physical maturation and his natural ability to shoot fast, according to head coach Matthias Ahrens.

"It's been said it takes 10,000 hours of training to become excellent," Ahrens said. "Looking back, when I took over the junior team 10 years ago, Nathan was on that team and he put a lot of effort and training into all those years.

"His skiing has improved over the years tremendously. First and foremost, it's important that the targets are hit. He is a good shooter in the way of getting a good shooting score, but he is also very quick getting in and out of the shooting lane and back onto the skis."

There is a distinct sound that signals success and failure in biathlon racing, when lead ammunition either hits or misses the target.

"The sound when you miss, it's a lot more blunt sound because it just hits a plate and stops the bullet dead," Smith said. "It's a good one when you hear the guys next to you doing that. Not when it's you."

Smith is a details man. He likes to take things apart and put them back together again. When he's not skiing or training, you'll find him in his garage tinkering on his motorcycle. Smith also built his own rifle stock.

"It's very tedious because you have to make it absolutely perfect, the measurements," Smith said. "You probably measure a thousand things to make it all fit together. I am probably the only top athlete in the world who made his own stock."

With files from CBC Sports