Leon A S, Casal D, Jacobs D
School of Kinesiology and Leisure Studies, University of Minnesota, Minneapolis 55455, USA.
J Cardiopulm Rehabil. 1996 May-Jun;16(3):183-92. doi: 10.1097/00008483-199605000-00006.
Epidemiologic evidence suggests that 8,368 kJ or 2000 kcal per week of moderate physical activity, including walking and stair climbing, can reduce risk of coronary heart disease (CHD). The goal of this study was to assess the effects of this amount of these two activities on physical fitness and risk factors for CHD.
Twenty-two healthy, slightly overweight, sedentary, normotensive, normolipemic men, age 22 to 44 years, were randomly assigned to an exercise or control group for 12 weeks followed by a 4-week washout period. The subjects then were crossed-over to the alternate group for an additional 12-week period. Exercise consisted of 5 days per week of supervised treadmill exercise plus stair climbing. Treadmill exercise consisted of walking for 45 minutes at 5.15 km per hour at 2% grade for a total of 19.3 km per week. Subjects also climbed 10 floors of stairs at a time at their own pace without prescribed target heart rates for a total of 50 floors per week. The estimated total weekly energy cost of the treadmill walking plus stair climbing was 8,368 kJ or 2,000 kcal. Mean observed heart rates were 55% and 82% of maximal heart rate during treadmill walking and stair climbing, respectively. Data from the two exercise periods and two control periods were pooled and compared by analysis of variance.
Sixteen subjects completed all phases of the study. Maximal oxygen uptake (VO2max) by the Bruce treadmill exercise protocol with metabolic gas measurements was below average for age at baseline, and was not significantly affected by 12 weeks of training. No significant changes were noted between groups in body weight or percent body fat (hydrostatic weighing), although there was a trend for loss of weight and fat with exercise training. Mean systolic blood pressure (119 mm Hg) was unchanged in both groups. However, diastolic blood pressure (72 mm Hg and 78 mm Hg for the treatment and control groups, respectively) showed an unexpected 6 mm Hg increase during the exercise period and a 5 mm Hg decline during the control period. Mean plasma lipid and lipoprotein levels were unaffected by training, except for a 16% reduction in triglycerides (P < .05). However, a 28% increase in plasma high density lipoprotein (HDL)-cholesterol (P < .01) was noted during the initial 12-week training period, which regressed during the washout period, and was not replicated during the second 12-week exercise period.
Twelve weeks of walking and stair climbing at a moderate pace and intensity at an energy cost of about 2,000 kcal per week failed to improve physical fitness or risk factors for CHD. A reduction in physical activities other than the prescribed exercise program, as reported by a physical activity recall questionnaire, probably contributed to an absence of an exercise response. A longer and/or a more intense activity program is apparently required to improve these modalities.
流行病学证据表明，每周进行8368千焦或2000千卡的适度体育活动，包括步行和爬楼梯，可降低冠心病（CHD）风险。本研究的目的是评估这两种活动的此运动量对身体健康和冠心病风险因素的影响。
22名年龄在22至44岁之间、健康、轻度超重、久坐、血压正常、血脂正常的男性被随机分为运动组或对照组，为期12周，随后有4周的洗脱期。然后受试者交叉到另一组，再进行12周。运动包括每周5天的有监督的跑步机运动加爬楼梯。跑步机运动包括以每小时5.15公里、坡度2%的速度步行45分钟，每周总计19.3公里。受试者还以自己的速度每次爬10层楼梯，无规定目标心率，每周总计爬50层。跑步机步行加爬楼梯的估计每周总能量消耗为8368千焦或2000千卡。在跑步机步行和爬楼梯期间，平均观察心率分别为最大心率的55%和82%。将两个运动期和两个对照期的数据合并，并通过方差分析进行比较。
16名受试者完成了研究的所有阶段。通过带有代谢气体测量的布鲁斯跑步机运动方案测得的最大摄氧量（VO2max）在基线时低于同龄人平均水平，且未受到12周训练的显著影响。两组之间的体重或体脂百分比（水下称重）无显著变化，尽管运动训练有体重和脂肪减少的趋势。两组的平均收缩压（119毫米汞柱）均未改变。然而，舒张压（治疗组和对照组分别为7
