INFLUENCE OF 12 WEEKS OF TRAINING BY BRISK WALKING ON POSTPRANDIAL LIPEMIA AND INSULINEMIA IN SEDENTARY MIDDLE-AGED WOMEN

The purpose of this study was to examine the influence of brisk walkin g on postprandial lipemia in 26 sedentary women aged 41 to 55 years. T he lipemic response to a high fat meal (mean +/- SEM: 73.8 +/- 1.3 g f at, 66% energy; 81.8 +/- 1.4 g carbohydrate) was determined pretrainin g and posttraining. Blood samples were obtained in the fasted state an d hourly for 6 hours after the meal. Serum was analyzed for triacylgly cerol (TAG), total cholesterol, high-density lipoprotein (HDL) and HDL ? cholesterol, apolipoproteins (apos) A-l and B, nonesterified fatty a cids (NEFA). glucose, and insulin. Subjects were randomly assigned to one of two groups: walkers (n = 13) followed a program of brisk walkin g (average of 21 +/- 1 [range, 17 to 27] min . d(-1) at 1.76 +/- 0.02 m . s(-1)), whereas controls (n = 13) maintained their habitual life-s tyle. Procedures were repeated 12 weeks later, with 48 hours between t he last training session and determination of postprandial lipemia. El even walkers and 13 controls completed the study. Responses over time were compared between groups (Mann-Whitney U, P < .05). Brisk walking improved endurance fitness and decreased body fatness, but had no infl uence on peak TAG concentration (walkers. 1.6 +/- 0.2 v 1.6 +/- 0.2 mm ol . L(-1); controls, 1.9 +/- 0.3 v 2.1 +/- 0.3) or the area under the TAG/time curve after the test meal. The area under the insulin/time c urve decreased in walkers relative to controls. These results suggest that in sedentary women aged 41 to 55, brisk walking attenuates the se rum insulin response, but not the lipemic response, to consumption of a high-fat mixed meal when these responses are determined 48 hours aft er the last exercise bout. Copyright (C) 1995 by W.B. Saunders Company