Hydrate Your Whole Grains
Many bakers have become accustomed to the notion that whole grain breads or breads containing a lot of whole grain flour are going to be heavy. Sure, they are going to be heavier than a baguette, but there are ways to make them lighter and more palatable. These flours can hold a lot of water due to the bran and if you give the dough that extra water, the results will be good.
As an example, a bread made with 100% whole wheat flour can easily take at least 80% hydration. To get all of the water into the dough try the double hydration technique. Hold back 10% of the water during the initial mixing and add it to the dough once the dough has reached a medium stage of development. Continue to mix to full development. Developing the gluten fully will increase the volume of the bread and improve the structure. During fermentation give the dough a punch and fold to increase the strength.