London: There are not many men who can still fit into the suit they wore on their wedding day, but it is a measure of the Duke of Edinburgh’s astonishing good health and vitality that he can make such a bold claim.

Just a few weeks shy of his 96th birthday, Prince Philip is considered to be in remarkably good shape and his secret appears to be deceptively simple — regular exercise, a moderate diet and a good dose of sheer will power.

Like any person his age, the Duke has had the occasional health scare, but their rarity has only served to highlight his general fitness and longevity. Those who know Prince Philip say none of this is an accident.

He works at keeping fit and, in a reflection of his days serving in the Royal Navy, has remained determined never to let himself go. 

As Ingrid Seward, editor of Majesty Magazine, said on his 90th birthday: “He is a man who has always looked after himself and taken care of his body. He’s someone who enjoys physical activity and he’s incredibly physically fit. He’s very careful about what he eats. If he puts on any weight at all, he will make sure he loses it.”  

The Duke, along with Prince Charles, is understood to undertake his own health and fitness regime, based on the Royal Canadian Air Force (RCAF) 5BX plan, first developed to help cadets get fit.

This can be carried out in a restricted space, with no warm up or equipment required, using five basic exercises to strengthen every muscle in the body. The Duke also prefers to walk and take the stairs wherever he can, and can still be seen behind the reins of a horse carriage in the grounds of Windsor Great Park. 

Keen walker

Buckingham Palace has long refused to elaborate on the specifics of the Duke’s exercise regime, but confirms he is a keen walker and adds, “it takes quite a lot of strength to control two or three ponies pulling a carriage”. 

With every passing birthday, the Duke’s diet has been the subject of repeated speculation. Those who have been able to observe him at close quarters say it is generally a low carbohydrate regime, similar to the Atkins-diet.

He is thought to prefer black coffee, rarely drinking tea of any sort, and enjoys the occasional fry-up for breakfast, although he also likes to start the day with oatcakes with honey. 

The Duke consumes small amounts of alcohol and one biographer observed that he is partial to a pale ale at lunchtime. Prince Philip’s long-standing personal tailor has vouched for the fact that he can still fit into the same naval uniform he wore on his wedding day. 

John Kent, of the small firm Kent, Haste & Lachter, in Lodnon’s Piccadilly, which has made the Duke’s suits for half a century, said: “He’s got a fabulous physique. There’s not an ounce of fat on him, which is why he wears his clothes so well. He’s very well proportioned. 

He’s got fairly long legs, and he doesn’t carry much weight.” Kent says that unusually for his clients, the Prince’s measurements have remained largely unchanged over the past five decades. In November last year, Prince Philip was able to tell experts at the Francis Crick Institute that he had not had flu for 40 years. 

He has also said that he hates consulting doctors because of their contradictory opinions. Inevitably, however, there have been low points when convalescence or even visits to hospital were required. 

Health issues

Shortly before his 95th birthday in June 2016, Prince Philip pulled out of the Battle of Jutland anniversary events following medical advice regarding a “minor ailment”. But he was at the Queen’s side a few days later for her official birthday celebrations.

In May 2014, the Duke had a “minor procedure” carried out on his right hand at Buckingham Palace and in June the previous year he spent two months convalescing after an exploratory operation on his abdomen. 

In December 2011, he was fitted with a heart stent and has twice been treated for bladder infections, including during the Queen’s Diamond Jubilee weekend in June 2012. 

On leaving hospital, the day before his 91st birthday, Prince Philip was asked if he was feeling better. He replied: “Well, I wouldn’t be coming out if I wasn’t.”

Fit for anything: Prince’s 5BX plan

The 5BX Plan was developed by exercise scientist Bill Orban to tackle weight gain and fitness loss among Canadian pilots and airmen at remote bases in the far north. The plan — 5BX stands for five basic exercises — requires no equipment and can be undertaken in a small space such as a bedroom. 
The exercises, to be done over an 11-minute period, are: 

1. Stretching 
2. Sit-ups 
3. Back extensions 
4. Push-ups 
5. Running in place