Tess, 51, revealed that Vernon, who came third on I'm A Celebrity, has been working hard to get fit and has keeping fit in the gym.
She told The Sun: "Ever since the first lockdown he's been on a mission to beef up and get fit and he went in there bigger than he's ever been."
Tess then revealed that Vernon's diet massively changed in the castle, as he went from having 5,000 calories a day to just 700.
She said: "He's been working out a lot since March and when Vernon gets into things – he has his passions and obsessions, whether it's golf, American football, triathlons and now working out – he goes for it.
"And he looks good! He's in good shape. The best shape."
Tess, who has been married to Vernon since 2003, also opened up about how hard she found it to be away from Vernon while he was in the castle.
The couple were separated for over a month as Vernon had to self-isolate before going into the show due to restrictions caused by the pandemic.
Vernon was seen getting emotional several times after receiving messages and special gifts from Tess and their daughters, Phoebe 16, and Amber, 11.
Tess, who was busy herself whilst presenting Strictly Come Dancing every week, also said she found it hard watching him on the show.
She worried that she got so worried about how he would cope with being too hungry and cold that she struggled to watch the show.
Tess added: "I was a nervous wreck every night! My heart was in my mouth and I don't think I slept for two weeks, I couldn't even string a sentence together!"
She shared several emotional videos after Vernon made it to the final, revealing how proud she was of him.