This week, Prince Harry was spotted jogging away from a gym class near his home at a luxury home in Montecito, California.
As Duke, 39, put on a pair of shorts, along with a beanie and a puffer jacket, he took off running, clearly with fitness in mind.
And the California-based royal certainly appears to be prioritizing his exercise regime as he approaches his 40th birthday in September.
Since he headed to the Golden State four years ago, the royal family's workout routine, which once revolved around rugby and polo, appears to have evolved – as his increasingly defined legs show in Harry's latest photos this week.
Compare photos of his princely pins while playing rugby in South Africa at a public meeting in 2015 with his current physique and it's clear he's changed the type of exercise he does, two fitness experts told FEMAIL.
Harry showed off his toned legs this week while jogging after a workout in Santa Barbara, near his home in California
In Durban during a rugby match in 2015, in the years before meeting Meghan, the royal's legs look simply athletic, but not quite as defined
More toned down? Fitness expert Lewis Paris said it was likely Harry had used different types of training – including yoga and pilates – to strengthen his legs (right, in Durban in 2015, the prince pictured in Santa Barbara this week)
Personal trainer Lewis Paris, founder of Lewis Paris Fitness, said regular visits to the gym are likely to have kept Harry looking toned and slim.
He said: 'A consistent exercise routine would be the reason for Harry's shapely legs.
'Based on my experience, I suspect he will run/jog once or twice a week, followed by two to three strength sessions, one focusing on HIIT and the other targeting the whole body, working all the major muscle groups attacked.
'Shaping the legs takes more effort than just losing weight. Doing some form of strength training will help shape the legs (body) you want.”
However, Paris also suspects that more meditative practices such as yoga and pilates also play a role.
Meghan's love of yoga is well known and it looks like Harry's toned legs are thanks to this age-old practice (Meghan and Harry pictured in Dusseldorf on September 16, 2023)
Mother of two Meghan is a well-known yogi. In 2017, she declared “yoga is my thing” and posed for a magazine showcasing her favorite health pastime.
And of course, the Duchess of Sussex's mother, Doria Ragland, is a longtime yoga teacher in their hometown of LA. 'His diet would be clean to stay slim. That will be an important part.
Says Paris: 'Pilates can help with core strength, posture development and mobility.
“So Prince Harry is likely to follow a weekly workout routine of three to five times a week to build muscle, maintain weight and stay fit.”
'With Harry's military background, he will benefit from sticking to a routine and maintaining the discipline and focus to get into shape and then maintain his physique.'