Maternal Aerobic Exercise, but Not Blood Docosahexaenoic Acid and Eicosapentaenoic Acid Concentrations, during Pregnancy Influence Infant Body Composition.

Although discrete maternal exercise and polyunsaturated fatty acid (PUFA) supplementation individually are beneficial for infant body composition, the effects of exercise and PUFA during pregnancy on infant body composition have not been studied. This study evaluated the body composition of infants born to women participating in a randomized control exercise intervention study. Participants were randomized to aerobic exercise (n = 25) or control (stretching and breathing) groups (n = 10). From 16 weeks of gestation until delivery, the groups met 3×/week. At 16 and 36 weeks of gestation, maternal blood was collected and analyzed for Docosahexaenoic Acid (DHA) and Eicosapentaenoic Acid (EPA). At 1 month postnatal, infant body composition was assessed via skinfolds (SFs) and circumferences. Data from 35 pregnant women and infants were analyzed via t-tests, correlations, and regression. In a per protocol analysis, infants born to aerobic exercisers exhibited lower SF thicknesses of triceps (p = 0.008), subscapular (p = 0.04), SF sum (p = 0.01), and body fat (BF) percentage (%) (p = 0.006) compared with controls. After controlling for 36-week DHA and EPA levels, exercise dose was determined to be a negative predictor for infant skinfolds of triceps (p = 0.001, r2 = 0.27), subscapular (p = 0.008, r2 = 0.19), SF sum (p = 0.001, r2 = 0.28), mid-upper arm circumference (p = 0.049, r2 = 0.11), and BF% (p = 0.001, r2 = 0.32). There were no significant findings for PUFAs and infant measures: during pregnancy, exercise dose, but not blood DHA or EPA levels, reduces infant adiposity.

The Influence of Maternal Aerobic Exercise, Blood DHA and EPA Concentrations on Maternal Lipid Profiles.

Exercise and polyunsaturated fatty acid (PUFA) supplementation independently improve lipid profiles. The influence of both exercise and PUFAs on lipids during pregnancy remains unknown. This study evaluated exercise, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) concentrations on lipids during pregnancy. Participants were randomized to aerobic exercise or control groups. From 16 weeks gestation until delivery, groups met 3x/week; exercisers performed moderate-intensity aerobic activity, controls performed low-intensity stretching and breathing. At 16 and 36 weeks' gestation, maternal blood was analyzed for lipids (total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglycerides (TG)), DHA and EPA. In intent-to-treat analysis, the aerobic group (n = 20), relative to controls (n = 10), exhibited a higher HDL change across gestation (p = 0.03). In a per protocol analysis, the aerobic group, relative to controls, exhibited 21.2% lower TG at 36 weeks (p = 0.04). After controlling for 36-week DHA and EPA, exercise dose predicts 36 weeks' TG (F (1,36) = 6.977, p = 0.012, r2 = 0.16). Aerobic exercise normalizes late pregnancy TG. During pregnancy, exercise dose controls the rise in TG, therefore maintaining normal levels. DHA and EPA do not have measurable effects on lipids. Regardless of PUFA levels, exercise at recommended levels maintains appropriate TG levels in pregnant women. Normal TG levels are critical for pregnancy outcomes, and further studies are warranted to investigate this association in broader populations.

Validity of a customized submaximal treadmill protocol for determining VO2max.

INTRODUCTION: A customized submaximal exercise test for cycle ergometry was reported as a superior estimate of maximum oxygen uptake (VO2max) in comparison to the traditional YMCA ergometry test. PURPOSE: Following similar methodology, we sought to validate a customized submaximal treadmill test (CustomTM) compared with the widely used Bruce submaximal protocol. METHODS: Participants (29 women and 21 men; age = 31.37 ± 11.44 year, BMI = 24.02 ± 3.03) performed a graded exercise test (GXT) with a subsequent exhaustive, square-wave bout for the verification of "true" VO2max. In counterbalanced order, subjects then completed submaximal protocols. The CustomTM protocol consisted of two 3-min stages estimated at 35 and 70% of VO2max, where VO2max was estimated with a linear regression equation utilizing sex, BMI, age, and self-reported physical activity. RESULTS: VO2 values from the GXT and verification bout were 47.2 ± 7.7 and 47.0 ± 7.7 ml kg-1 min-1, respectively (ICC = 0.99, CV = 2.0%, TE = 0.83 ml kg-1 min-1), with the highest value used as "true" VO2max (47.7 ± 7.7 ml kg-1 min-1). Neither the Bruce (45.95 ± 6.97 ml kg-1 min-1) nor the CustomTM (47.3 ± 9.4 ml kg-1 min-1) protocol differed from "true" VO2max. The CustomTM had a "very large" measurement agreement with "true" VO2max (ICC = 0.78, CV of 9.1%, TE = 4.07 ml kg-1 min-1). Bruce had a "large" measurement agreement with "true" VO2max (ICC = 0.62, CV of 10.0%, TE = 4.51 ml kg-1 min-1). CONCLUSION: The CustomTM was superior to the Bruce protocol, because it included a stage below and above gas exchange threshold, yielded a better measurement agreement for "true" VO2max, and was more time efficient.