With the Winter Games in PyeongChang approaching, a brother and sister duo from northern Washington state have been busy in Alaska training and gearing up for South Korea.

Team USA cross country ski athletes Sadie and Erik Bjornsen have been working non-stop since May: Skiing, running, weight training and skiing some more.

"Nobody is watching, but in order to be the best, we're training somewhere between 700-1000 hours each year," Erik explained.

The siblings started skiing at the age of three. Their older sister and parents skied, so at first it was just something they did as a family.

"Everything was sort of a competition, so naturally we evolved into these athletes that were showing up to races as a family," Sadie recalled.

After finding success as youth skiers, both Sadie and Erik headed north to Alaska. The sibling skiers each spent a year at the University of Alaska before enrolling at Alaska Pacific University, where there's a strong Nordic ski program.

The Bjornsens began to flourish on the international stage, under the watchful eye of two-time Olympic coach Erik Flora.

"We operate this team like a family, we are together countless hours during the year," Flora described. "So to have a brother and a sister, where they bring a good energy to the group, it's been fantastic."

For the siblings, it helps having a family member there during the tough times.

"Sometimes you need to let out some of that negative energy and you never want to do that with your teammates, or your coaches," Sadie explained. "So to have family around to sort of release that and then talk thru it and then to find a way to jet out of there, it's really unique and I often feel like its one of the secrets to success for me."

If you want to follow the Bjornsen's journey to South Korea, Sadie has a blog at sadiebjornsen.com.