Physical Conditioning Facilitates the Exercise-Induced Secretion of Beta-Endorphin and Beta-Lipotropin in Women

EXERCISE training is used increasingly to prevent and treat disease, and millions of healthy persons participate in strenuous sports; yet, the mechanisms by which exercise produces various clinical effects are imperfectly understood. Emerging evidence suggests that endogenous opioid peptides influence diverse functions linked with the body's energy balance, including appetite,1 thermorégulation,2 lipolysis,3 and reproduction.4 Preliminary observations of athletes indicate that the acute expenditure of energy during exercise stimulates secretion of opioid peptides, but the lack of data on endocrine functions in subjects of experiments and the wide range of reported basal concentrations of hormones weaken this conclusion.5 6 7 No studies have . . .