Victoria de Marichalar y Borbón in Bathing Suit is "Wasting Time in the Caribbean

Victoria de Marichalar y Borbón is enjoying a sun-kissed vacation in the beautiful Caribbean. Borbón shared a picture of herself looking blissfully serene, wearing a purple bikini while relaxing on a lounger. "Wasting time in the Caribbean," she captioned the post. How does she stay so fit? Read on to see 5 ways Borbón stays in shape and the photos that prove they work—and to get beach-ready yourself, don't miss these essential 30 Best-Ever Celebrity Bathing Suit Photos!

Borbón loves nothing more than exploring a city on foot. "Because walking helps strengthen muscles in your lower body, it can also improve knee and hip arthritis pain," says Michael Fredericson, MD, director of the Physical Medicine and Rehabilitation division of Stanford University. "As walking increases your heart rate and helps you work multiple muscle groups at the same time, you absolutely burn calories and will lose weight if you do so often. And remember, even if you don't work up a sweat, you're still burning calories."df44d9eab23ea271ddde7545ae2c09ec

Borbón loves protein-packed salads made with avocado, shrimp, and boiled eggs. "Avocados are high in fat with 60 percent of this being monounsaturated fats, which research suggests helps to protect against heart disease and lower blood pressure," says registered nutritionist Jo Lewin. "They are also an excellent source of potassium, folate and fiber, all of which benefit the heart and cardiovascular system."

Borbón loves horses. "Riding is a total body workout. Your legs, arms and core work together to control and communicate with the horses," says professional hunter-jumper rider and trainer Melissa Gruber. "Really, riding is a partnership sport; the rider and the horse support and guide each other. Just like dancing or ice skating with a partner, horse and rider communicate through body language and touch."

Borbón enjoys the many mental and physical health benefits of swimming. "Every time I go for a swim I feel like the earth and my incredible swim colleagues have enabled me to have experienced something pretty amazing," says Dr. Jenny Martin, a physician and clinical pharmacologist at the University of Newcastle. "You get a release of hormones that make you feel good, like the molecules that are in morphine drugs, and other feel-good hormones like serotonin, dopamine. After an ocean swim in winter, you sometimes get a temporary natural high when you get out … definitely a euphoric feeling."

Borbón loves hitting the slopes for invigorating skiing sessions. Skiing is especially effective as a lower body workout. "The mix of highly coordinated movements with different types of exercise modes and the mix of eccentric, isometric and concentric muscle work might be seen as quite unique when compared with other types of physical activity," says Thomas Stöggl, a skiing researcher and associate professor of sports science and kinesiology at the University of Salzburg.