Anything that causes your muscle activity to increase and your heart and lungs to work harder will count as exercise. Even walking – in fact especially walking. Walking has some amazingly good advantages when it comes to getting fit in that it is free, absolutely anyone who is reasonably physically sound can do it, and being out in the fresh air will do you nothing but good.
I have to admit that if I did not own dogs I would not go for a walk every day, especially in the winter when the rain is sluicing down in buckets from an icy, grey sky and a lazy wind is blowing. A lazy wind may sound nice, but in Yorkshire it means a wind that blows through you as opposed to going round you, taking your breath away and chilling you to the bone in the process!
But even in the worst stormy winter days there is always something to see along the quiet tracks and fields that we’re lucky enough to live near. In the spring and summer, walking is pure delight, with something new to see almost every day, from the beginning of March when the first blossom starts to form, through to November when the last red leaves drop.
So mood is raised, your skin gets a good dose of vitamin D from the daylight and you burn some calories as well. Okay so strolling along admiring the view in summer isn’t going to burn that many, but when the wind is howling and all you want to do is get the walk over with and get home it is surprising how briskly you can stride out 
Walking for an hour at a brisk pace that makes you feel warm, slightly breathless and a bit sweaty will tone all your leg muscles, strengthen your leg bones and burn around 200 cal. If you want to increase the toning effect of your walking, find a hill to stride up, which makes your thighs, hamstrings and butt muscles work much harder. Walking does not have the same high impact stresses on the joints as running does, and is suitable for anyone.