Take a dip
Swimming is an obvious beachside exercise, but an excellent option nonetheless. Depending on the sea-state and how much effort you apply it can be a great low-impact form of cardio, meaning almost everybody can get a good workout in the water, plus you need minimal equipment to get started (especially if you're swimming in the Med!)
The most efficient way to burn calories is front crawl, although breaststroke is a great option for building core strength and improving balance and posture.Â
