Waking up with stiffness, hearing cracking sounds in your knees, or feeling that your legs no longer feel strong should not be brushed off as “just aging.” While many people assume these changes are inevitable, they often signal that the body isn’t getting—or properly using—the nutrients needed to support muscles, tendons, and joints.

Joint weakness develops gradually. It usually starts as mild discomfort and, if ignored, can turn into ongoing pain, inflammation, and even a fear of movement. Over time, this can limit independence and reduce overall quality of life. The encouraging part is that the body still has a strong ability to repair itself when it’s given the right support.

Nutrition plays a major role in this process. Certain fruits, when eaten regularly and in the right way, can help boost collagen production, calm inflammation, and support strength and mobility in the knees and legs at any age. Below are six key fruits, ranked from moderate to most powerful in their impact.

Number 6: Kiwi

Kiwi is often overlooked, but it’s extremely rich in vitamin C, which is essential for producing and maintaining collagen. Without enough vitamin C, cartilage and joint tissues struggle to repair themselves.