Bassett D R, Vachon J A, Kirkland A O, Howley E T, Duncan G E, Johnson K R
Exercise Science Unit, University of Tennessee-Knoxville 37996-2700, USA.
Med Sci Sports Exerc. 1997 Sep;29(9):1250-4. doi: 10.1097/00005768-199709000-00019.
In calculating the physical activity index (PAI) on the college alumnus questionnaire, it is assumed that 8 kcal are expended for every 20 steps climbed. This value is equal to an energy cost of 0.40 kcal.step-1. Since it is assumed that subjects climb and descend an equal number of stairs, the total value reflects the energy cost of stepping up (estimated at 0.30 kcal.step-1) and stepping down (estimated at 0.10 kcal.step-1). However, these values appear to be based on theoretical calculations rather than empirical observation. The purpose of this study was to quantify the energy cost of stair climbing and stair descending by measuring oxygen uptake. Twenty subjects performed continuous stair-climbing and stair-descending on an escalator at a stepping rate of 70 step.min-1. Heart rate was monitored by telemetry, and oxygen uptake was measured by the Douglas bag technique from 5 to 7 min. Results showed that the gross energy cost of stair climbing is 8.6 METs, and that of stair descending is 2.9 METs. Thus, for a 70-kg person the gross caloric costs of ascending stairs (0.15 kcal.step-1) and descending stairs (0.05 kcal.step-1) are one-half of the values previously assumed. In conclusion, the algorithm for calculating PAI on the college alumnus questionnaire should be modified to reflect a total cost of 0.20 kcal for going up and down one step. Even more precise estimates can be obtained by adjusting for body weight (going up and down one flight of stairs requires 1.63 MET.min).
在计算大学校友调查问卷中的身体活动指数（PAI）时，假定每爬20级台阶消耗8千卡能量。该值等于每级台阶0.40千卡的能量消耗。由于假定受试者上下楼梯的步数相等，所以该总值反映了上楼（估计为每级台阶0.30千卡）和下楼（估计为每级台阶0.10千卡）的能量消耗。然而，这些值似乎是基于理论计算而非实证观察得出的。本研究的目的是通过测量摄氧量来量化上下楼梯的能量消耗。20名受试者以每分钟70级台阶的步速在自动扶梯上持续进行上下楼梯运动。通过遥测监测心率，并采用道格拉斯袋技术在5至7分钟内测量摄氧量。结果表明，上楼的总能量消耗为8.6梅脱，下楼的总能量消耗为2.9梅脱。因此，对于一个体重70千克的人来说，上楼（每级台阶0.15千卡）和下楼（每级台阶0.05千卡）的总热量消耗是之前假定值的一半。总之，大学校友调查问卷中计算PAI的算法应进行修改，以反映上下一级台阶的总消耗为0.20千卡。通过根据体重进行调整（上下一段楼梯需要1.63梅脱·分钟），可以获得更精确的估计值。
