The influence of verbal encouragement during assessment of maximal oxy
gen consumption of subjects scoring as Type A and Type B on the Jenkin
s Activity Survey, Form T was examined. Fourteen Type A and 12 Type B
scorers performed two randomly assigned maximal tests on a motor-drive
n treadmill with and without verbal encouragement during testing. Trea
dmill time, oxygen consumption (VoverdotO(2)), heart rate, and respira
tory exchange ratio at exhaustion were examined. Verbal encouragement
led to significantly greater treadmill lime, VoverdotO(2) and respirat
ory exchange ratio for Type B scorers when compared with the no-encour
agement trial. Treadmill time, VoverdotO(2) heart rate, and respirator
y exchange ratio at exhaustion were not different between treatments f
or the Type A scorers. Type A scorers ran significantly longer without
encouragement than Type B scorers; however, when encouragement was pr
ovided, treadmill time for Type A and Type B scorers did not differ si
gnificantly. The results suggest that attainment of maximal effort is
not dependent on verbal encouragement for Type A scorers, whereas verb
al encouragement is necessary to assure attainment of maximal physiolo
gic effort for those individuals scoring as Type B.