Exercise Metabolism: Historical Perspective.

The past 25 years have witnessed major advances in our knowledge of how exercise activates cellular, molecular, and biochemical pathways with regulatory roles in training response adaptation, and how muscle "cross-talk" with other organs is a mechanism by which physical activity exerts its beneficial effects on "whole-body" health. However, during the late 19(th) and early 20(th) centuries, scientific debate in the field of exercise metabolism centered on questions related to the sources of energy for muscular activity, diet-exercise manipulations to alter patterns of fuel utilization, as well as the factors limiting physical work capacity. Posing novel scientific questions and utilizing cutting-edge techniques, the contributions made by the great pioneers of the 19(th) and early 20(th) centuries laid the foundation on which much of our present knowledge of exercise metabolism is based and paved the way for future discoveries in the field.