Walking is still your best outdoor exercise for health maintenance. For weight loss, the pace needs to be faster and preferably in more challenging terrain (up hill). Long walks require good hydration the same as bikers. Get a diet plan that gives you quick results if you are carrying 25 or more pounds before starting long hikes in hot weather. Over-heating is not good.
How would you like to be in this kind
of good shape? Biking is his choice of
outdoor exercise!