The benefits of circuit weight training (CWT) for senior adults are well documented. Most studies, however, are of short duration (< 3 months) with no follow-up of the longer-term effects of CWT on physical fitness. Over how many years do the gains made from systematic CWT remain before individuals regress to their levels of fitness prior to training? Through the Senior Activity and Rejuvenation Project (SARP) supervised circuit weight training programs and regular fitness evaluation has been provided to several older adults for 15 years. The purpose of this study was to examine, over 10 years, the changes in physical fitness in a group of active, older adults who systematically participated in CWT. The simple question asked was "How long would fitness gains from CWT delay the losses in fitness that occur with aging?" Eleven senior adults (meanage=79; range 71-93 yrs; 6 male, 5 female) two now deceased, who circuit weight trained for 8 (n=1) and 10 (n=10) years were studied. Supervised CWT and pre and post fitness evaluations occurred between January and June during 10 consecutive years. CWT routines were varied, included at least 10 stations, 1-2 sets, and were performed 2-3 times per week. No CWT related injuries occurred. Physical fitness measures included TBW, % fat estimated by 3-site skinfold, 1 RM chest press, 1 RM leg press, bent-leg sit ups in 1 min., and sit and reach flexibility. The initial fitness test administered prior to any CWT was set as a baseline and yearly changes in fitness were expressed as a percentage gain or loss from baseline. Improvements in sit ups and fat loss were the most durable with chest press strength returning to baseline the most quickly. Using a composite estimate of fitness change, males aged about 6 years before returning to baseline, females about five years. Systematic CWT for older adults appears to provide a safe and useful means of delaying physical fitness decline.