A follow-up study was conducted to re-evaluate a group of obese middle-aged women (n = 13), eight of whom had completed an 18-wk supervised (3 d/wk) plus unsupervised (2 d/wk) conditioning intervention program (at least 90 min per day) as the exercise plus diet group; while five of the remainder served as the control group. Each session had included a 25- to 45-min jog/run at intensities between the heart rate (HR) corresponding to lactate threshold (LT) and that slightly above the HR @ LT. During 1 year following the program, the women participated in self-controlled training such as running, aerobic dancing, or jazz dancing 2.6 +/- 1.1 d/wk. Dietary intake averaged approximately 1736 +/- 152 kcal/d at the pre-treatment, 1404 +/- 124 kcal/d at the post-treatment, and 1645 +/- 147 kcal/d 1 year after the post-treatment. Interestingly however, oxygen uptake corresponding to LT (VO2 @ LT), maximal oxygen uptake (VO2max), weight, systolic blood pressure, and the ratio of high-density lipoprotein cholesterol to total cholesterol (HDLC/TC) observed 1 year after the post-treatment were significantly different from the original pre-treatment and/or mid-treatment values. For instance, the significant 42% increase (14.7 +/- 2.4----21.3 +/- 4.2 ml/kg/min) in VO2 @ LT and 18% increase (0.284 +/- 0.106----0.335 +/- 0.093) in HDLC/TC from the pre-test to post-test were maintained throughout the 1-year follow-up period, suggesting no detrimental effect either on a cardiorespiratory fitness factor or on an anti-atherogenic factor. These findings indicate that physiologic status of obese middle-aged women engaged in a conditioning intervention program may not regress to pre-treatment status for at least one year after completion; provided they continue to participate in a 2.6-d/wk self-controlled training program with dietary intake of 1600-1700 kcal/d. Another interesting finding was that significant relationships existed between individual changes (delta) in training frequency and individual changes (delta) in physiologic variables (i.e., delta VO2max, delta VO2 @ LT, delta WT, delta fat, and delta HDLC/TC) during the follow-up study. It is concluded that, although the improved physiologic status of obese women can be maintained fairly well during 1 year following the conditioning program; continuation of training (3 d/wk or more) should be critical, either supervised or self-controlled, for successful maintenance of lost weight (8.2 +/- 2.9 kg) and improved fitness.