Super-immunity
MILE 1: It takes just 10 minutes exposure to sunlight for your body to synthesise enough vitamin D to start strengthening your bones, and boost immunity to harms from Covid to cancer.
MILE 1000: Walking has enhanced the inner layer of collagen that makes skin supple and resilient, and rejuvenated its mitochondria – your skin’s army of antiageing organelles. Your immune system is humming and has slashed the number of days lost to illness in an average year. And walking as little as nine minutes daily between March and September has been enough to sustain sufficient vitamin D levels throughout the whole of the winter.