The purpose of this study was to investigate the effect of constant endurance cycling exercise below Ventilatory Threshold (VT), under different pedal rate/torque regulations (PTR), on muscle oxygenation, as well as cardio-respiratory function and energy metabolism. Eight healthy male adults participated in the study for three tests. The first test was to examine the maximum oxygen uptake (VO₂max) using a ramp loading measurement of 60 rpm, 20 watt/min ; and an individual 80%VT load was obtained. The second and third tests (random) were to measure heart rate (HR), blood pressure (MAP), expired gas and NIRS data before, during and after 30 min 80%VT constant cycling exercise with low pedal rate/high torque (LPHT : 32 rpm, 23.3±6.0Nm) or high pedal rate/low torque (HPLT : 79rpm, 9.4±2.4Nm). As a result, HPLT showed higher values in HR (p<0.001), MAP (p<0.001), VO₂ (p<0.001), VCO₂ (p<0.001) and RER (p<0.05), than LPHT ; but LPHT showed a higher fat consumption rate than HPLT (p<0.05). Significant PTR effect were recognized for the parameters of the tissue hemoglobin index (THI) (p<0.001) and oxygenation hemoglobin (ΔO₂Hb) (p<0.01) ; and both indicated higher values for HPLT than LPHT ; but LPHT showed insignificantly (p=0.066) higher de-oxygenation hemoglobin (ΔHHb) than HPLT. Moreover, the significant time effects of THI and ΔO₂Hb were also recognized. In conclusion, this study indicated that during constant cycling exercise below VT, HPLT might result in greater muscle blood volume, higher muscle oxygenation concentration and higher HR and VO₂ compared with LPHT. These results suggest that, HPLT might be effective in alleviating the working load on lower limbs, as well as promoting muscle oxygenation, cardiorespiratory function (systemic oxygen supply) and energy metabolism. Therefore, HPLT constant cycling exercise below VT could be used in a rehabilitation program as a beneficial exercise for elderly people with decreasing muscle strength in their lower limbs.

The decrease of balance capacity is considered as a high risk factor of fall accident, so it is important for the middle-aged and elderly people to keep balance capacity on a high level. In this study, we investigated the effects of aqua exercise on dynamic and static balance function. Thirty-two middle-aged women (56.6±8.1 years) participated a 60-min aqua exercise program three times per week for eight weeks. After exercise intervention, body weight, body mass index, grip strength, side step, shuttle stamina walking test were significantly improved (p<0.05-0.001). Functional reach (p<0.001) and total length of centroid shake with eye close condition (p<0.05) was significantly improved, but with eye open condition was not changed. However, when we evaluate the total length of centroid shake by T-score, static balance performance with eye open and close condition was significantly (p<0.05) improved in the below average groups. In addition, measurement value of functional reach was also improved in these groups. These results indicate that aqua exercise benefits not only physical muscle strength and endurance capacity, but also balance function in middle-aged women. Particularly aqua exercise is more effective for the subjects with lower static balance function before intervention.

We investigated the relationship between body weight reduction and intensity of daily physical activities assessed with 3-dimensional accelerometer during a 3-month exercise program. Twenty-six middle-aged women (58.1±7.4 yrs.) participated in this study. Participants underwent a 90-min endurance exercise intervention once a week, and a 3-dimensionsal accelerometer was attached through the program. Body weight (BW), body mass index, fat mass and percent body fat were reduced significantly (p<0.001), while diastolic blood pressure (p<0.01) and shuttle stamina walking test (p<0.05) improved significantly after the exercise intervention. Moreover, a significant negative correlation was observed between the changes in BW and total activity time (TAT) per day of more than 3METs (TAT≥3METs)(r=−0.580, p<0.01) and TAT≥4METs (r=−0.627, p<0.001). To the contrary, the daily steps and the TAT≥2METs were not related to the changes in BW. After adjusting daily steps, TAT≥3METs (β=−0.630, p<0.01) and TAT≥4METs (β=−0.659, p<0.01) were still significantly related to the changes in BW. These results indicate that weight reduction has a much closer relationship with exercise intensity than daily steps. It is important to keep both quantity and intensity of exercise in the unsupervised exercise program aimed at weight reduction.