HALF a glass of champagne a week is the key to a healthy life according to Britain’s fittest great-granddad, who turned 100 on Wednesday.

Sam Heggessey, from Uxbridge, was surprised by a party and a personal message from Richard Branson at the gym he has attended several times a week for 20 years.

The retired accountant and great-grandfather of six attends yoga, tai-chi and pilates classes with his 83-year-old wife Doris.

“I avoid red meat and alcohol – although I treat myself to half a glass of champagne,” said Sam.

“I try never to miss my weekly yoga and pilates classes, so the party was a lovely surprise when I arrived at the club on Monday for my usual class.

“Receiving the special message from Sir Richard Branson was rather unbelievable – I can’t wait to show my daughters and grandchildren.”

Virgin Active Stockley Park was decorated with 100 red balloons and members were treated to a three-tier Victoria sponge cake decorated with figurines of Sam hard at work on his yoga.

Doris, who helped plan the party, said: “It was a wonderful surprise for him and so lovely to celebrate Sam’s birthday with our good friends and the staff at Virgin Active who we see so regularly.”

Operations manager Christopher Knightly said: “Sam and Doris have been loyal members for many years and, when we found out his birthday was this week, throwing him a special birthday party was the least we could do.”