CALGARY -- The defending Olympic women's bobsled champions are back in the same sled once again.

Canada's Kaillie Humphries and Heather Moyse will reunite at this weekend's season-opening World Cup at Canada Olympic Park as they begin their buildup to the Winter Games in Sochi.

Humphries won a world title last year and has reached the podium at 13 straight events. Moyse, who competed in track cycling and rugby while taking a break from bobsled, has returned in top form after undergoing hip surgery a year ago.

The veteran brakeman from Summerside, P.E.I., has set personal-best start times since coming back and won a push challenge event last weekend. She also set a new start record during selection races in Whistler, B.C.

"That just made me excited about what I can possibly contribute and what I can give back to this team this year," Moyse said in a recent interview. "Because of that excitement and being named to the team as Canada 1 and being put into Kaillie's sled, I think that excitement is just transcending.

"Kaillie and I are both really excited about what we can do and what we can possibly experience this year."

Humphries and Moyse first started sliding together in January 2009 and won Olympic gold a year later. Off and on, they have spent about 2 1/2 years together as a duo.

They were all smiles after two practice runs on Thursday.

"It went straight to comfortable mode," Humphries said of being back with her old partner. "I know she's in the best shape she's ever been in and it's really exciting going into this season."

Humphries, from Calgary, won the overall World Cup title last season with Chelsea Valois of Zenon Park, Sask. Valois will team with Edmonton's Jenny Ciochetti in the Canada 2 sled for the season opener.

Moyse suffered a serious ankle injury at the 2010 Rugby World Cup. She later took up track cycling before deciding about a year and a half ago to concentrate on both bobsled and rugby.

She underwent hip surgery last fall and now feels as strong as ever entering the Olympic season. Her performance at testing made the decision to return to the Canada 1 sled with Humphries an easy one.

"Based on the results, it was a no-brainer in terms of teaming us up together," Moyse said.

There will be some changes in the men's sleds as well.

Pilot Chris Spring of Calgary will team with Jesse Lumsden of Burlington, Ont., in the two-man and four-man sleds. Lumsden won the World Cup title with pilot Lyndon Rush of Humboldt, Sask., last season.

Spring and Lumsden will be joined by Ottawa's Cody Sorensen and Ben Coakwell of Saskatoon in the four-man sled.

Rush will team with Calgary brakeman Lascelles Brown in the two-man and four-man sleds. David Bissett and Neville Wright, both of Edmonton, will join them in the four-man.

The other Canadian sled will feature Justin Kripps of Summerland, B.C., who will drive Toronto's Tim Randall, James MacNaughton of Newmarket, Ont., and Graeme Rinholm of Medicine Hat, Alta.

The Canadian skeleton team is also looking strong this season.

Calgary's Sarah Reid, who won bronze at the 2013 world championship, leads the women's side this week. She will be joined by Cassie Hawrysh of Brandon, Man., and Calgary's Robynne Thompson.

The men's lineup for the season opener includes Eric Neilson of Kelowna, B.C., and Calgary-based racers John Fairbairn and Dave Greszczyszyn.

"We have a really strong team," Neilson said. "We came out in selections, that's always the most stressful part. So the team is ready to go."

Mellisa Hollingsworth of Eckville, Alta., and 2010 Olympic champion Jon Montgomery of Russell, Man., will open the season on the Intercontinental Cup circuit. Athletes can qualify for Sochi while competing on that circuit or at the World Cup level.

Some 350 skeleton and bobsled competitors from 30 countries are expected to participate this week, including World Cup four-man champ Alexsandr Zubkov of Russia and World Cup skeleton champions Martins Dukurs of Latvia and Marion Thees of Germany.

Competition kicks off Friday afternoon with the skeleton races. The two-man bobsled follows in the evening.

On Saturday, the four-man bobsled is set for the morning with the women's bobsled scheduled for the afternoon.