Hormonal responses to exercise and training.

This research paper delves into the limited understanding of hormonal responses to exercise across different species including horses and humans. It mentions that various factors, including the intensity and duration of the exercise, can influence these hormonal responses that are propagated through the endocrine system and further affect the metabolism of muscular fuels primarily triglycerides and glycogen.

Hormonal Response to Exercise

• The study acknowledges that our understanding of the hormonal response to exercise is still narrow. It highlights that changes in plasma concentration of some hormones happen early in exercise due to neuronal stimulation. However, hormones that are pituitary-dependent need hormonal stimulation to respond.
• The researchers point out that although it is feasible to monitor changes in plasma concentrations of hormones, the underlying mechanism causing the change is not always clear. Furthermore, unless the nonprotein-bound, or active, form of the hormone is also determined, observations about changes in plasma concentration lack sufficient information.

Impacts of Exercise Intensity and Duration

• The research discusses the influences both intensity and duration of exercise can have on hormonal responses. These responses are modified by impulses from either the working muscles or motor centers, via the central nervous system. These impulses affect the response of the glands of the endocrine system either directly via pituitary hormones or indirectly via the sympathoadrenal system.
• The initial response to the onset of exercise is an increase in sympathoadrenal activity and secretion of pituitary hormones. This results in a decrease in the plasma concentration of insulin and an increase in virtually all other hormones.

Shifting Hormonal Balance and Metabolism

• From the shift in the hormone balance, there is a change in the metabolism of intra- and extra-muscular triglycerides and glycogen as fuels for muscular exercise. According to this study, altering the mobilization of one fuel source can have an effect on its combustion, as well as on the mobilization and combustion of the other.
• When exercise is extended, hormonal response is influenced by additional factors such as temperature, glucose availability, oxygen tension, and changes in plasma volume.

Effect of Training on Hormonal Responses

• One of the key findings of the study is that the effect of training on hormonal responses generally soothes or ameliorates the reactions. This points to an increased efficiency of muscular energy metabolism as a result of the training process.