Roger Federer has been rampaging through the Wimbledon draw for the past week, but thanks to the time-warping magic of television, he was also in the Swiss Alps on Sunday night.

The 36-year-old starred in an episode of Running Wild with Bear Grylls, a reality show that takes celebrities and tests their wilderness-survival skills. 

Since Federer happens to be a 20-time Grand Slam champion, tennis racquets had to be involved somehow. They were initially used, quite effectively, as snowshoes.

"I could be running thorough this snow!" Federer said. 

Later on, the racquets came out again, when Grylls asked Federer to blast a roped tennis ball up a snowy cliff so they could then use the rope to scale the mountain face: 

In one rather gross part of the show, Federer reached his hand into a near-frozen pond to pull out a half-eaten, dead fish and eat one of its eyeballs.

"When you eat it, it'll probably, like, explode with blood and fluid," Grylls warned him:

In addition to the physically demanding tasks, Federer and Grylls had sit-down talks to discuss family, dreams and fulfilling your potential. There were plenty of dad jokes, too. 

The pair ended the show with the world's smallest game of ping-pong. Playing up to 11, Federer found himself down from the very start, but, in a 2017 Australian Open-like comeback, he took the final four points to win the match 11-9. 

In a higher-stakes competition, Federer lost to Kevin Anderson in five sets in the Wimbledon quarterfinals on Wednesday.