Elderly participants experiencing difficulty in chair rising and with a maximum knee-extensor torque below 87.5 N · m were randomized to different versions of a strength-training program for the knee-extensors: to a high-guidance group (HG; two group sessions supervised by a physical therapist and one unsupervised home session per week, n = 17), a medium-guidance group (MG; one supervised group session and two unsupervised home sessions per week, n = 16), or a control group (C; no exercise, n = 16). Maximal isometric knee strength increased more in HG than in C (p = .03) and with increasing guidance (p = .03). The effect was mainly the result of participants with low initial strength. Walking speed increased more for HG than for C (p = .02) and than for MG (p = .06). No statistically significant improvements were seen on other functional tests. In summary, the study shows a trend toward better results with more supervision, but more and larger studies are needed to confirm this.