To the Editor: Normal aging corresponds with a deterioration in postural stability and a subsequent increase in fall rates.1 Physical activity can address some aspects of this age-associated physiological decline,2 with exercise programs that incorporate balance retraining having been found to improve postural stability.3 The majority of activities of daily living, such as walking and climbing stairs, are performed in the anterior–posterior direction. Consequently, when postural stability is challenged in this plane, humans are more likely to maintain stability. The ability to maintain stability is less in the less-common mediolateral direction, which has led to the high incidence of detrimental falls occurring in this plane.4 To improve balance in the mediolateral plane for an aged population, the effect of a physical activity intervention that targeted this direction was investigated. From a convenience sample of 29 subjects (10 men, 19 women) with a mean±standard deviation age of 71.0±7.2 completed pre- and postintervention testing and attended 1-hour physical activity intervention classes twice a week for 10 consecutive weeks. Eligibility inclusion criteria required the participants to be living independently; be aged 60 and older; and have no current musculoskeletal, cognitive, or cardiovascular dysfunction that would impede their ability to perform exercise or follow instructions. Three clusters of outcome measures were used: questionnaires (Modified Physical Activity Scale for the Elderly, Mini-Mental State Examination, Goldberg Anxiety and Depression Scale, Medical Outcomes Study 36-item Short Form Survey, Modified Falls Efficacy Scale, and Exercise Benefits), clinical measures of strength and postural stability (grip strength, range of motion, static sway, coordinated stability, and maximum balance tests), and functional measures of postural stability (Berg Balance Scale, Tinetti Balance and Gait test, Timed Up and Go Test, and functional and lateral reach tests). The physical activity program was designed to improve musculoskeletal strength and postural stability primarily in the mediolateral plane of movement. The average number of classes attended was 18.6 of 20 (93.0%). There were nonsignificant improvements in the questionnaire scores, and some of the activities listed as “becoming easier” included the ability to lift heavier objects and to walk for longer and being better able to cope if balance became compromised, and balance was better. A significant improvement for the eyes-closed foam sway meter condition was observed, with a reduction in mediolateral sway of 16 mm (P<.001) and reduction in anterior–posterior sway of 12 mm (P<.001). Several balance, strength, and functional stability measures also showed significant improvements, as listed in Table 1. By specifically targeting physical activities in the mediolateral direction twice per week for 10 weeks, several significant improvements were found in the outcome measures, indicating the ability of an aged population to improve their balance. Postural stability in the mediolateral plane is affected more significantly with age, but little literature exists to explain the effect of exercise on postural stability in this plane. This research focused on a community-dwelling adult population, and although this population is at risk for falls and fall-related injuries, they are often overlooked for intervention because of greater logistical difficulties associated with recruitment and implementation of exercise programs than those living in the hospital or respite care facilities.5 The adherence rate was higher (93.0%) than for a similar 10-week intervention study reporting an adherence rate of 85%.6 The high adherence rate implies the program was attractive to the group. The circuit class design was time-efficient and did not require multiple sets of the same equipment, thereby lessening intervention-associated costs. The strength and balance exercises were each specifically chosen to increase strength in the upper and lower body and were alternated during the circuit. This allowed appropriate rest between muscle groups,7 and each exercise was designed to be performed in the anterior–posterior and mediolateral planes of movement. These findings have demonstrated improved balance measures for a population with and average age of 71 that was reasonably active. Future studies of the same exercise intervention could be implemented in a frailer, more-fall-prone participant group to elicit the effectiveness in a higher-risk group. Given the incidence and effect of falls in the older population, this study found improved musculoskeletal strength and postural stability in the at-risk mediolateral plane of movement, as well as the more common anterior–posterior plane. Conflict of Interest: The editor in chief has reviewed the conflict of interest checklist provided by the authors and has determined that the authors have no financial or any other kind of personal conflicts with this letter. Author Contributions: All authors contributed equally to the development of this letter. Sponsor's Role: There was no sponsor.