Cardiorespiratory and Muscular Activity Responses on Sandy Beach Walking for Health

Luck of exercise is known as one of the factors for develops lifestyle disease. In the recent years, aerobic exercises was to performed by many people for awareness to health. Walking was selected as health exercise in many case. Method of increasing the exercise intensity of walking has been reported various researchers, however it was not enough data to evaluate walking effect in sand beady surface. Purpose of this study was to investigate the cardiorespiratory response and muscle activity during sandy beach walking. Healthy six subjects participated in this study after informed consent. It was performed walking each 5 minutes sandy beach and asphalt surface, respectively. Average Walking speed were adjusted 3 and 4 km per hours by speed meter. While there walking experiments, surface electromyographic (EMG) data were recorded from the following five muscles (tibialis anterior, medial gastrocnemius, rectus femoris, biceps femoris and erector spinae muscles) at a sampling frequency 1000 Hz. The raw EMG signal was removed direct current component and integrated the EMG after full-wave rectification. In addition, heart rate response was recorded every 5 seconds during each walking. Oxygen uptake and heart rate response during treadmill walking were measured every 10 seconds, and calculated the relationship between oxygen uptake and heart rate (HR-VO2 relationship). Oxygen uptake during sandy beach and asphalt surface walking were estimated by the HR-VO2 relationship. Statistical proceeding used one way repeated measures of analysis of valiance. Statistical significance was accepted at p < 0.05. The result of this study, muscle activity of tibialis anterior during asphalt road walk was higher than sandy beach walk at 3 km, and erector spinae during sandy beach walk was higher than asphalt road walk at 4km. Heart rate response and oxygen uptake of sandy beach walking were higher than asphalt road walking in both speed. Consequently, it was suggested that sandy beach walking was benefit as health exercise, by mobilized muscles that are not used asphalt walking.