摘要:

The physiological responses of normal walking and walking on a dual action treadmill which incorporates arm exercise were compared in 29 men and 37 women. Subjects completed six, 5-min steady-state exercises at 2.0, 3.0, and 4.0 mph (0.89, 1.34, 1.79 m-s−1) and 3% incline with and without arms. Estimated METs calculated according to the ACSM equations were compared with the actual METs. The men's ventilation (VE), and &OV0312;O2(1-min−1, ml-kg−1·min−1, and METs) were significantly (P< 0.001) higher at all speeds and for both conditions than the women's. There were no gender differences (P> 0.05) in heart rates (HR), respiratory exchange ratio, and ratings of perceived exertion (RPE) for each condition. The arm conditions yielded significantly (P< 0.001) higher responses at each speed for VE, 1-min−1, ml-kg−1·min−1, and METs, RPE, and HR. Although there were no significant (P> 0.05) differences in HR between the men and women for each condition, the relationships between ml-kg−1·min−1, and HR differed. The actual METs obtained during the arm conditions were significantly (P< 0.05) higher than those estimated for both the men and women at all speeds. It was concluded that using the arms while walking on a dual action treadmill increases the energy costs an average of 55% above normal walking.

ISSN:0195-9131    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Accurate methods of estimating total daily energy expenditure (TDEE) that are inexpensive and differentiate activities of varying intensities are needed in obesity research. We compared minute-by-minute heart rate (HR) monitoring and the 7-d physical activity recall (PAR) questionnaire with doubly labeled water (DLW) for the measurement of TDEE and physical activity in 14 obese women (45% ± 4% fat, mean ± SD) before and during 12 wk of weight reduction. TDEE was measured over 2 wk by DLW. HR monitoring was conducted for 3 d, with individual &OV0312;O2/HR calibrations applied to HR data above 3 METs. PAR revealed the amount of time spent in sleep, moderate, hard, and very hard activities during 1 wk, with time spent in light activities determined by difference. Mean TDEE values, expressed as the % difference from DLW, prior to weight loss were −5.2 ± 10.8% by HR and 3.4 ± 14.4 by PAR, and during the diet were +0.9 ± 14.1% by HR and +0.9 ± 14.7% by PAR. Individual variability was high for both HR (−24.0 to +25.6%) and PAR (−27.4 to +36.2%). Energy expended in physical activity prior to weight loss were 3.97 ± 1.23 MJ-d−1by DLW, 3.91 ± 0.90 by HR, and 4.79 ± 0.95 by PAR. During weight loss, physical activity values by DLW, HR, and PAR were 4.31 ± 1.18,4.84 ± 2.22, and 4.64 ± 1.06 MJ-d−1, respectively. In summary, HR and PAR accurately assessed TDEE and physical activity for the group, but individual variability was high.

ISSN:0195-9131    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

A number of cycle ergometers are presently being used in a variety of laboratory applications for which the quantification of power output is required. To calculate the power output of cycle ergometers with varying sized flywheels, the circumference of the resistance track on the flywheel is multiplied by the number of flywheel revolutions produced with one complete revolution of the pedal. This provides the “effective distance travelled,” and by selecting an appropriate combination of pedalling rate plus flywheel resistance, any desired power output can be produced.

ISSN:0195-9131    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Ski charging was measured using giant-slalom style skis as gliding capacitors. The voltage measured across the plates was proportional to the charge on the base. While resting on dry snow or suspended in the air, the voltage was slowly reduced by the data logger itself. On wet snow the decay was much faster. While stationary on powder snow the ski developed a slightly negative voltage, showed a small, transient positive peak when motion began, rapidly dropped to negative values, and then assumed a quasi-steady climb to positive voltages. A great deal of noise was superimposed on the general features of the signal when skiing on hard or bumpy surfaces. Thus, the accumulation of charge to high levels was only possible with long runs in deep powder. The rate of charging increased with speed but was not affected by use of one “antistatic” wax, and another such wax actually increased the measured voltage over that of an unwaxed base.

ISSN:0195-9131    

出版商:OVID    

年代:1995

数据来源: OVID

ISSN:0195-9131    

出版商:OVID    

年代:1995

数据来源: OVID