The purpose of this study is to examine the cardiovascular and metabolic responses between dynamic and static exercise when a leg press exercise is performed. Seven participants (20-21 yrs) were recruited for the experiment. Four modes of dynamic or static leg press exercise were assigned in two combined conditions: a unilateral or a bilateral condition and two exercise intensities with 20% and 40% of maximal voluntary contraction (20% MVC, 40% MVC). The duration of the dynamic exercise and the static exercise at 20% MVC was six minutes, and the static exercise at 40% MVC was three minutes. In the dynamic exercise, ventilation (VE), O 2 uptake (VO 2 ), heart rate (HR), and systolic and diastolic blood pressures (SBP, DBP) reached the steady-state after 3 min exercise, while in the static leg press, these responses continued to increase at the end of exercise. The alteration in VO 2 mostly depended on both exercise intensity and the oneor two-leg condition during the dynamic leg press, whereas no significant difference in VO 2 during the static leg press was found in the four modes. The alterations in rate-pressure product (RPP) depended solely on exercise intensity and leg condition. These findings suggest that the static leg press causes a greater rise in HR, SBP, and DBP. In addition, RPP appears particularly sensitive to experimental modes.

The purpose of this study was to comparatively investigate the energy expenditure of jumping on sand and on a firm surface. Eight male university volleyball players were recruited in this study and performed 3 sets of 10 repetitive jumps on sand (the S condition), and also on a force platform (the F condition). The subjects jumped every two seconds during a set, and the interval between sets was 20 seconds. The subjects performed each jump on sand with maximal exertion while in the F condition they jumped as high as they did on sand. The oxygen requirement for jumping was defined as the total oxygen uptake consecutively measured between the first set of jumps and the point that oxygen uptake recovers to the resting value, and the energy expenditure was calculated. The jump height in the S condition was equivalent to 64.0Ϯ4.4% of the height in the maximal jump on the firm surface. The oxygen requirement was 7.39Ϯ0.33 liters in S condition and 6.24Ϯ0.69 liters in the F condition, and the energy expenditure was 37.0Ϯ1.64 kcal and 31.2Ϯ3.46 kcal respectively. The differences in the two counter values were both statistically significant (pϽ0.01). The energy expenditure of jumping in the S condition was equivalent to 119.4Ϯ10.1% of the one in the F condition, which ratio was less than in walking and close to in running.

The purpose of this research is to examine the heart rate responses and the perceived exertion in college students during scootering, and to examine if scootering possibly makes heart rate increase up to the level that can c o n t r i b u t e t o m a i n t a i n i n g o r d e v e l o p i n g cardiorespiratory fitness. Five male students (20-23 yrs) participated in this research, mainly assigned to scooter on an official 400m-tartan track. Each session of scootering was six minutes. Each subject did three sessions of scootering at different speeds, slow, ordinary, and very fast. During the scootering, heart rate was measured using a Polar Vantage XL. Immediately after each session, the subjects were questioned about their perceived exertion. To evaluate heart rate during scootering on the track, maximal heart rate was measured in advance with graded maximal tests. In each speed in the track trial, the mean heart rates and the standard deviations were 106 ± 5.9, 129 ± 4.2, and 179 ± 13.7 beats/min respectively. They correspond to 54.0 ± 4.2%, 65.8 ± 4.2%, and 91.2 ± 5.5% of the maximal heart rate respectively. The mean and standard deviation of perceived exertion based on Borg's scale in each scootering session were 7.2 ± 0.45, 10.2 ± 1.10, and 16.6 ± 2.79 respectively. Conclusively, at ordinary speed, the heart rates of the college students on a tartan track were situated around the level of the lower boundary which the American College of Sports Medicine recommended to develop and maintain cardiorespiratory fitness for apparently healthy people. If people have places to ride a scooter briskly, their heart rate could rise above the minimum level.

Physiological responses to riding a scooter (scootering) are compared with walking, running and cycling at three different treadmill speeds (80, 110 and 140m mint) and slopes (0 %, 4 % and 8 %). Five healthy male college students performed all exercises at different intensities in four trials a day, one or two days a week. Each experiment comprised of a 5-20 minute resting period, followed by 3 minutes of exercise and 10-50 minute recovery time. Apart from stationary cycling to measure maximal oxygen uptake, all exercises were performed on a treadmill. Heart rate (HR), oxygen uptake ('O2), carbon dioxide production (cTCo2), pulmonary ventilation (VE), respiration rate (RR) and respiratory exchange ratio (RER were measured every 15 seconds, and averaged using a computerized breath-bybreath expired gas monitor. From these measurements, the ventilation equivalent for C02 (VE/VC02) was calculated. No significant differences in the HR-V02 relation with exercise intensity were observed among the different types of exercise. The slopes of the regression lines for VE-V02 and RER-V02 in scootering were steeper than those in other exercises (p< 0.05). A significant correlation was noted between stroke frequency and RR in scootering (R =0.727, p < 0.001). Measurement of the changes in VE/ VC02 during scootering at 73, 80 and 90% V02max revealed a notably (p<0.05 larger `short period of depression' (undershooting) with a peak around 30 seconds after exercise, which was rarely observed with the other exercises examined. These results suggest that the cardiorespiratory responses to scootering differ from those to walking, running and cycling, due to the unique locomotion pattern of this vehicle.