From pricey wearable devices to your phone, it has never been easier to track your daily physical activity, or lack of it. And if you're like many Americans and spend nine-plus hours sitting every day ...

A 28-year-old man has told of how he 'shrunk' fat on his belly and arms, while building leg muscle by taking on an extreme walking challenge. British YouTuber Jack Massey Welsh saw changes in his body ...