Objectives: To determine if a small body size at birth is associated with an unfavorable metabolic profile and a reduced response to exercise training in young adults. Methods: Thirty-six college students, all singletons born to term, participated. Subjects were defined as either high ponderal index (HIGHPI) or low ponderal index (LOWPI). LOWPI was defined as below the 10th percentile of the PI-for-gestational age distribution. HIGHPI was defined as greater than the 10th percentile. Subject groups were matched pair-wise on age, sex, BMI, and pretraining physical activity level. Subjects completed an 8-week aerobic exercise program. Pre- and post-training measurements included a blood lipid profile. Results: The LOWPI group, when compared to the HIGHPI group, exhibited higher total (183.6 mg dl-1 vs. 150.9, P=0.04) and LDL cholesterol (114.8 mg dl-1 vs. 80.2, P = 0.019) values prior to exercise training. After training, these values decreased in the LOWPI group, eliminating the group difference. Various blood lipid ratios were more favorable for the HIGHPI group, both before and after training. The inclusion of maternal smoking as a covariate attenuated group differences for pretraining TChol, pre-training TG:HDL, and post-training HDL cholesterol. Conclusions: An 8-week exercise program corrected some, but not all, of the differences in blood lipid values between the LOWPI and HIGHPI group. The persistent group difference in blood lipid ratios suggests a higher long-term risk of chronic disease in the LOWPI group independent of lifestyle intervention. Am. J. Hum. Biol. 25:844-846, 2013. © 2013 Wiley Periodicals, Inc.