This study examines the effect of two different exercise approaches on balance and frailty measures among more than 200 community-dwelling individuals greater than 70 years of age. Exercises are provided for 15 weekly sessions on an individual basis for participants randomly assigned to a Balance Training group. Training consists of center-of-mass feedback displayed on a motor under static conditions, or, in later sessions, as the floor surface is moved, with eyes open or closed. This high technology interface provides instantaneous information about displacement of body weight in space so that balance can be enhanced. An alternative procedure is comparatively simple and requires little expense or space. Tai Chi Quan was originally developed as a martial arts form but has been used for centuries in China as an exercise among elderly citizens. Participants randomly assigned to this intervention meet twice weekly for 15 weeks to learn a condensation of 108 Tai Chi forms into 10 that emphasize movement components often restricted or absent with aging. A third group serves as a control for exercise interventions by meeting weekly for 15 sessions to discuss topics of interest such as memory loss, drug management, and nutrition. All subjects are screened prior to assignment, and a host of physical, behavioral, and functional measures are assessed before and after the intervention as well as 4 months later. Measurements unique to the Atlanta site include: balance with eyes closed, programmed force-distribution changes when stance is perturbed, cardiovascular assessments, WAIS, Affects Balance Scale, and a survey of home environment.