In conditioning, muscle mass accumulated through strength training.
That part of a food (e.g., fiber) that, when eaten, forms a mass that promotes intestinal movement (peristalsis).
In nutrition, a substance that absorbs water in the intestinal tract. The increased mass helps to stimulate peristalsis. Bulk materials include bran cereals, cellulose, lignins, and psyllium. They are used therapeutically to treat constipation and other bowel disorders.
A part of the nourishment that is referred to as “roughage” because of its texture, and is rich in cellulose. Despite being indigestible, it plays a vital role in regulating the digestive system.