Perspectives on molecular and cellular exercise physiology.

A challenge to applied physiologists is to continue to apply new methods to their field. The purpose of this review is to speculate how recent advances in the fields of molecular and cell biology might be applied to exercise physiology to provide greater insights into the mechanisms underlying adaptations to a single bout of exercise and to repeated bouts of exercise (training). The review is organized to consider the actions occurring outside the cell, through the cellular membrane and cytoplasm to the nucleus. These topics are as follows: blood-borne signals, polypeptide growth factors, membrane receptors (insulin receptor, adrenergic receptors, acetylcholine receptors, phosphorylation of receptors, and mutant receptors), transduction through the plasmalemma (glucose transporters and G proteins), second messengers (phosphatidylinositol phosphates and calcium), cis sequences required for muscle-specific gene expression, transcriptional regulation by physiological signals, and gene expression. Exercise physiology is a challenging discipline that integrates molecules, cell-to-cell interaction, tissues, and the whole organism during the physiological stress of exercise by the live, unanesthetized animal.