United Kingdom, Jan. 23 -- Dick Van Dyke still goes to the gym three times a week as he approaches his 100th birthday.

The 99-year-old actor is planning a "big party" to celebrate his centenary in December later this year, while he also opened up on the secret to his "age and physical condition".

Speaking to Ted Danson and Mary Steenburgen on their 'Where Everybody Knows Your Name' podcast, he said: "When you think... I go back to 1925, I'm almost 100. This is insane. I'm going to have a big party.

"Somebody said, 'to what do you attribute your age and physical condition?' and I said, 'I've always exercised.'

"Three days a week, we go to the gym, still. Three days a week."

Sitcom legend Danson - known for his roles in the likes of 'C...