Neural regulation of cardiovascular response to exercise: role of central command and peripheral afferents

During dynamic exercise, mechanisms controlling the cardiovascular apparatus operate to provide adequate oxygen to fulfill metabolic demand of exercising muscles and to guarantee metabolic end-products washout. Moreover, arterial blood pressure is regulated to maintain adequate perfusion of the vital organs without excessive pressure variations. The autonomic nervous system adjustments are characterized by a parasympathetic withdrawal and a sympathetic activation. In this review, we briefly summarize neural reflexes operating during dynamic exercise. The main focus of the present review will be on the central command, the arterial baroreflex and chemoreflex, and the exercise pressure reflex. The regulation and integration of these reflexes operating during dynamic exercise and their possible role in the pathophysiology of some cardiovascular diseases are also discusse

Cardio-metabolic responses during horse riding at three different speeds

Purpose: The purpose of the present investigation was to study the metabolic demand and cardiovascular response during a typical horse riding session. Methods: To this aim, 19 (9 male, 10 female) riders, regularly participating in competitions, were enrolled. They underwent a preliminary, incremental exercise test on a cycle-ergometer to assess their anaerobic threshold (AT) and VO2max. Then, participants underwent a riding training session, which comprised periods of walking, trotting, and cantering for a total of 20 min. Oxygen uptake (VO2), carbon dioxide production (VCO2), and heart rate (HR) were obtained throughout the preliminary and riding test by means of a portable metabolic system. Moreover, excess of CO2 production (CO2excess) and oxygen pulse (OP) were also calculated to obtain an estimate of anaerobic glycolysis and stroke volume. Results: The main result was that all collected parameters remained below the AT level throughout the riding session, with the exception of HR that approached the AT level only during cantering. In detail, during cantering, average VO2, VCO2, HR, CO2excess, and OP values were 1289 ± 331 mL min−1, 1326 ± 266 mL min−1, 158 ± 22 bpm, 215 ± 119 mL min−1, and 7.8 ± 1.6 mL/bpm, respectively. Conclusions: It was concluded that riding imposes only light to moderate stress on the aerobic and anaerobic energy systems. Moreover, cardiovascular reserve is only moderately recruited in terms of inotropism, while chronotropism can be stimulated mor

Gender differences in cardiovascular functions during exercise: a brief review

Exercise is a major challenge for the cardiovascular apparatus, since it has to provide adequate oxygen supply to exercising muscles and to guarantee arterial blood pressure regulation. Several adjustments, such as heart rate increase, contractility enhancement, and venous return modulation are made to accomplish this task. Furthermore, regular physical training induces several physiological adaptations due to an increase in parasympathetic and a decrease in sympathetic tone and to chronic increases in cardiac pre-load and after-load. There are gender-related physiological and morphological differences in the cardiovascular adjustments and adaptations to physical exercise in humans. In this review, we briefly summarize these differences. Moreover, differences in ECG pattern between sexes are discusse