The aim of this study was to determine the relationship between heart rate (HR) drift and deep temperature (T_m) and blood volume (Total Hb) in active muscle (vastus lateralis) during constant-load exercise. Seven healthy men performed a moderate-intensity 60-min cycling exercise. HR increased significantly from 3 min after the start of the exercise to 30 min and 60 min. T_m and Total Hb in active muscle significantly increased in the first half of the exercise (3-30 min), but not significant in the last half (30-60 min). These results suggest that although HR drift is related to the increase in Total Hb with the rise in T_m, the relationship is weaker in the last half than in the first half of the exercise.
In this study we applied least squares approximation to exact monthly age for physique and motor ability in South Korean children, and examined the age composition. We then attempted to build a regression evaluation chart with physical elements. The subjects included 116 boys and 87 girls aged 3- and 4-year-old. The physical attributes measured were physique and motor ability. A least squares approximation polynomial was applied to the measured values for physique and motor ability at exact month of age. A change with age was seen in height and weight for both boys and girls. However, no change with age in BMI was seen. Changes with age in physical ability items were seen in both boys and girls for one-leg standing, standing long jump, tennis ball throw, side step, and over-and-under. An attempt was made to construct a regression evaluation chart for month of age with consideration of this age composition.
The purpose of this study is to investigate the aging change of center of pressure (COP) reverse response and its relationship with the strength of the lower limb muscles involved in backward stepping. On the basis of the reverse response phenomenon (RRP) of the COP displacement in backward stepping, an RRP-based index was defined, which was compared among different age groups. From the results of this analysis, it was observed that the elderly group significantly shows high value at RRP distance as compared with a young group, and the elderly group showed a significant correlation among the RRP distance, time, and the COP displacement distance toward the supporting leg. Its confirmed in the elderly group to tend to increase the RRP distance that was a mechanical factor of the COM transfer in backward stepping. Furthermore, the results of this study suggested the existence of an association between the step time and the knee extension muscular strength.
The purpose of this study was to assess physical activity levels during cycling at a given spontaneously chosen speed on a 3.2 km of test road with a flat road, and 3% or 6% gradient slope roads, using different support settings; no support (assist-OFF) and support (assist-ON), with an electrically power-assisted bicycle. Twenty healthy women volunteered for this study. The physical activity levels estimated by %HRR on the slope roads for assist-OFF reached the recommended level for health promotion. However, those for assist-ON, which were 30% lower than those for assist-OFF, did not reach the recommended level. The net energy consumption while cycling on the test road for assist-ON was 30% lower than that for assist-OFF. From the standpoint of health science, we need to decrease the power-assist level or switch off the power according to the gradient of the road.
We assessed muscle activity levels exerted with leg extensors during cycling on a flat road, and 3% or 6% gradient slope roads, using three different support settings; no support (OFF), economy support (ECO), and power support (POW), with an electrically power-assisted bicycle. Muscle activity levels estimated by electromyogram recordings of leg extensors during cycling were compared with those used for daily physical activities such as chair-standing and stair-climbing/descending. Muscle activity levels for OFF at the 6% gradient slope were 1.7-2.0 times greater than those used for chair-standing, and those for ECO and POW at 3% and 6%-gradient slopes were at the same levels as those used for chair-standing. However, muscle activity levels for OFF, ECO and POW on the flat road and POW at the 3%-gradient slope were lower than those used for chair-standing (p<0.05). The results suggest that the electrical power-assist function may lower activity levels of leg extensor muscles during daily town cycling.