Dr. Bassett et al., ENERGY-COST OF STAIR CLIMBING AND DESCENDING ON THE COLLEGE ALUMNUS QUESTIONNAIRE, Medicine and science in sports and exercise, 29(9), 1997, pp. 1250-1254
In calculating the physical activity index (PAI) on the college alumnu
s questionnaire, it is assumed that 8 kcal are expended for every 20 s
teps 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 numb
er 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 theoretic
al calculations rather than empirical observation. The purpose of this
study was to quantify the energy cost of stair climbing and stair des
cending by measuring oxygen uptake. Twenty subjects performed continuo
us stair-climbing and stair-descending on an escalator at a stepping r
ate of 70 steps.min(-1). Heart rate was monitored by telemetry, and ox
ygen 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 ME
Ts, 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 prev
iously assumed. In conclusion, the algorithm for calculating PAI on th
e 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 es
timates can be obtained by adjusting for body weight (going up and dow
n one flight of stairs requires 1.63 MET.min).