[AstralStorm]

Weight gain is orthogonal to this, as you could just adjust the diet. You would have to do multiple hours of exercise to lose weight that is not just water.

But the difference for cardiovascular and respiratory systems and especially back and neck muscles is big with something as simple as basic walking exercise.

Exercise is not for weight loss, it's too stay fit and healthy. And yes, small regular exercise beats hard exhausting bursts.