walking is the berst exercise.....is it true??

That depends on what you want to achieve, but one thing that can be said for walking is that nearly everyone can do it. Most people can walk, so you don't have to do it alone either. You get fresh air, and you can do it everywhere. You don't need fancy equipment or shoes, so it's cheap. You just need proper shoes if you're walking for hours, and possibly a water bottle.

I think it's a good exercise by it isn't the best. Because it depends of what you expect for an exercise. Walking works with all your body parts and increase your resistance and your legs force. But if you want conditioning your physical and waork hard all your body parts you'll need to go to gym with a good instructor. If you want lose weight Boxe, Swimming, Tennis, Basketball and Soccer are hard recommended. If you want equip sport to increase force you can play Football. If you want agility you can play Hockey or Baseball. If you want fun, strong legs and arms but without lose much weight you can play Volleyball. So the tipe off exercise you'll do depends of what you expect. But for people who don't like sports and want lose weight and make their legs strong without increase muscles walk is the best exercise.