Medicine & Science in Sports & Exercise:
May 2006 - Volume 38 - Issue 5 - p S482-S483
Friday Afternoon Poster Presentations: Posters displayed from 1:00-6:00 p.m.: One-hour author presentation times are staggered from 2:00-3:00 p.m., 3:00-4:00 p.m., and 4:00-5:00 p.m.: F-27 Free Communication/Poster - Diet or Exercise and Chronic Disease Risk: FRIDAY, JUNE 2, 2006 2:00 PM - 5:00 PM: ROOM: Hall B
PURPOSE: To examine the postprandial blood lipid responses to a high carbohydrate meal with and without a prior bout of moderate aerobic exercise in lean and obese young women.
METHODS: Lean women (n =10; age=18.9 ± .88 yrs; Ht = 63.0 ± 4.5cm; Wt = 61.1 ± 4.8 kg; BMI = 22.2 ± 2.2 kg/m2; waist circumference = 72.7 ± 6.0 cm) and obese women (n=10; age 21.2 ± 1.7 yrs; Ht = 66.1 ± 3.0cm; Wt = 85.1 ± 14.6 kg; BMI = 29.9 ± 3.7 kg/m2; waist circumference = 92.6 ± 8.2cm) were selected from the student body at Texas Christian University. On two occasions separated by at least one week, during the morning hours, all participants consumed a high carbohydrate liquid meal (80% CHO, 15% PRO, 5% fat) (17.5 kcal/kg/BM) followed by a six-hour blood sampling protocol. The meal trials were preceded by either an exercise (EX) or nonexercise (NO-EX) trial on the previous day. Exercise consisted of 60 min of cycle ergometry (60% VO2peak), during the afternoon before the meal trial. Blood was analyzed for plasma triglycerides (TAG), total cholesterol (TC), blood glucose (BG), and insulin (IN).
RESULTS: TAG levels over the six-hour sampling period were significantly lower in the lean compared to the obese (p= 0.021) and lower in EX compared to NO-EX (p= 0.006). Area under the curve analysis (AUC) for TAG showed similar significant group (p=0.016) and condition (p=0.003) effects with EX AUC reduced by 16.2 % (lean) 15.6% (obese). There were no significant changes in total cholesterol in either the lean or obese females as a result of exercise.
RESULTS: showed a tendency for reduced glucose responses; however, these results were not significant for either the time course (p=0.053) or AUC (p=0.083) analyses. Insulin AUC showed a significant reduction in EX (p=0.040) for both groups with a 9.7% (lean) and 25.8% (obese) reduction in the AUC.
Discussion: Prior exercise improved triglyceride responses following the intake of a high carbohydrate meal. In addition, obese women demonstrated a greater postprandial lipemic response compared to their lean counterparts. There were tendencies for improved glucose utilization with exercise between the lean and obese participants. Acute exercise can improve postprandial lipemic responses and may also be influential in improving postprandial glucose and insulin responses following a large meal in both lean and obese populations.
This study was supported by the John Peter Smith Sports Fellowship Program.