This paper is a description of the improvements in isoinertial strength and power following 12 weeks of training on a Cybex Arc Trainer. The subject was a 54-year-old woman (weight 60.9 kg, height 1.70 m) at a moderate level of fitness who had not been training for at least 12 weeks prior to the case study. Training took place an average of 2-3 times per week for a duration of between 20 and 30 min. (average 25 min) at a resistance progressing from 15 to 18 and incline beginning at 7 and ending at 10. Subject varied the use of interval and steady state training. Isoinertial strength was measured using pneumatic leg press, and anaerobic peak and average power production as measured using a 30s Wingate test on a mechanically braked cycle ergometer. Leg extension strength increased from 642N to 807N (25.7%), while leg extension power increased from 105W to 115W (9.5%). Peak power during the Wingate test improved from 266.3W to 321.1W (20.6%) and for Average power from 189.0W to 282.2W (49.3%). Our results show substantial increases in isolated leg strength and power, as well as in anaerobic mechanical power as a result of 12 weeks of unsupervised training in our 54-year old female subject. We suggest that controlled studies using an appropriate sample size and targeted training group be done to ascertain the generalizability of these findings.