April 8 (UPI) -- Lindsey Vonn, Sofia Kenin and actor Hugh Jackman were among the celebrities to respond to an online tennis lesson posted by Roger Federer on social media. Their results were mixed.
Federer posted a 59-second clip of himself rapidly knocking a tennis ball against a wall at his house Tuesday on Twitter and Instagram. He sported white shoes, white pants, a white jacket and a white fedora for the drill.