The effect of intensity and energy expenditure on post exercise
insulin responses in women.
Ben-Ezra, Vic, Catherine Jankowski, Kevin Kendrick, and David Nichols.
Department of Kinesiology, Texas Woman's University, Denton, TX
76204
APStracts 2:0332A, 1995.
The purposes of the study were to compare insulin responses following
rest and exercise of two different intensities and equal total energy
expenditure (EE); and to examine these responses in normoglycemic
women. Twenty-four untrained women (age = 23.4 + 0.9 yrs) completed
three randomly assigned treatments over the course of a 3-4 week
period: rest, 40% VO2 max x 87 min (LOW) and 70% VO2 max x 50 min
(HIGH). Total EE was 1821 + 61 and 1692 + 59 kJ, heart rates were 119
+ 2 and 163 + 2 bpm, and VO2 was 17.1 and 27.2 ml_kg-1 _min-1 for LOW
and HIGH, respectively. Fifteen to seventeen hours posttreatment and
12 hours postprandial each subject drank a 75 g glucose solution
(OGTT). Blood samples were drawn prior to, and at 30,60,90,120, and
150 min postingestion and analyzed for glucose and insulin. Glucose
areas and responses at the same time points across treatments were
similar. Area under the insulin curve was significantly lower
(p<.05) after HIGH (51864 + 3780 pM x min) compared to rest
(61009 + 4425) but LOW (59191 + 5307) was not different from either
rest or HIGH. The insulin level at the 120 min timepoint was
significantly (p< .01) lower after HIGH (290.8 pM) compared to
rest (391.7 pM). Based on these results, exercise related changes in
insulin responses are more dependent on exercise intensity than on
energy expenditure in untrained women.
Received 31 October 1994; accepted in final form 19 July 1995.
APS Manuscript Number A113-4.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 30 July 1995.