The association with pain and improved performance evolved from research in many laboratories showing that when muscles are stretched, they activate specific metabolic pathways responsible for building new and stronger muscle protein. In fact, after intense exercise, muscle remodeling, which ultimately leads to improved performance, takes place. Athletes have interpreted this research as "more is better". The more pain, the greater the improvement in performance through an increase in the size and strength of muscle cells.
Research, however, shows this is not the case. When muscles are overly damaged through intense exercise it takes longer for them to recover. Instead of building new and stronger muscles, the metabolic machinery is focused on repairing damaged ones. A better approach is to control the degree of muscle damage and here nutrition can play a major role. In a study conducted at James Madison, researchers controlled muscle damage by having cyclists consume a carbohydrate/protein beverage during an intense exercise bout.
Twenty-four hours later they evaluated the ability of the cyclists to conduct a series of leg extensions. Cyclists whose muscle damage was controlled with nutrition were able to do 14% more leg extensions than the uncontrolled group. The bottom line–for the serious endurance athlete, muscle damage control should be an integral part of their overall nutrition regimen.