Kate, 32, has been slowly returning to engagements following a prolonged absence from public life because of her battle with a severe pregnancy sickness known as hyperemesis gravidarum.
The royal is expecting her second child with husband Prince William next April.
Yesterday, the brunette showed she's on the mend as she smiled and joked with young athletes at a SportsAid workshop at the GSK Human Performance Laboratory in West London.
Kate, who is the organisation's patron, joined thirty young athletes between the ages of 16 and 20 to watch as they took part in workshops designed to help them prepare for the Olympic Games in Tokyo in 2020.
The sports-loving royal took part in two cognitive tests that help measure reaction time in athletes and joked: "Finally, something I can do while I am pregnant!"
Among the athletes that Kate spoke with was Paralympic wheelchair athlete David Weir CBE.
"It's been a privilege to meet the athletes here today and share their achievements and challenges with the Duchess," he said.
"It's a long road to Tokyo but her support will make a big difference and with the right approach, it's achievable. It's exciting to think these athletes could be part of the next generation of British sporting heroes and I wish all of them the very best of luck."
Clarence House announced Kate's second pregnancy in September, revealing that once again she was suffering from severe pregnancy sickness. During her pregnancy with Prince George, who was born in July 2013, the duchess was briefly hospitalised with the condition.
She was forced to cancel several engagements earlier this year while being treated by doctors at Kensington Palace.
Kate's first pregnancy in pictures:
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