Effects of aerobic fitness on cardiac autonomic modulation during supine and upright posture

• Published in: Journal of exercise physiology online 2013-08, Vol.16 (4), p.92-100
• Main Authors: Moreira, Debora do Nascimento, Pecanha, Tiago, Guerra, Zaqueline Fernandes, da Silva, Lilian Pinto, Nakamura, Fabio Yuzo, Laterza, Mateus Camaroti, de Lima, Jorge Roberto Perrout
• Format: Article
• Language: English
• Subjects: Exercise; Health aspects; Heart beat; Physiological aspects; Physiological research; Posture
• ISSN: 1097-9751; 1097-9751

The purpose of this study was to assess the influence of aerobic fitness on cardiac autonomic modulation in sedentary subjects in the supine and upright posture. Twenty-four young men (22 [+ or -] 2.5 yrs) were assessed for aerobic fitness, including supine and upright posture heart rate and heart rate variability analysis. From the maximal exercise test V[O.sub.2] max values, the subjects were divided into two groups: Low V[O.sub.2] max (n=13) and High V[O.sub.2] max (n = 11). Student's f-test was performed to compare the autonomic variables between the groups (P < 0.05). We observed higher values of [HF.sub.nu] and [LF.sub.nu] during the supine posture and greater responses of the same ratios during the upright posture in the High V[O.sub.2] max group compared to the Low V[O.sub.2] max group. The results of this study indicate that higher aerobic fitness promotes positive cardiac autonomic responses, both during supine and upright posture. Key Words: V[O.sub.2] Max, Heart Rate Variability, Physical Activity