Journal of Aging Research that resistance training increases muscle strength in older adults, thereby greatly attenuating the losses of strength, power, and muscle mass that occur during aging [61, 62]. Moreover, resistance training has robust eﬀects on the muscle strength and overall physical function of older adults [63, 64]. Further, recent studies have found that re- sistance-training interventions produce clinically meaningful improvements in gait speed in older adults with mobility limitations and that increased muscular power contributed to these improvements [65]. Numerous studies provide evidence that skeletal muscles, even among frail older adults, adapt vigorously to resistance training with marked myoﬁbre hypertrophy [62]. This is an important ﬁnding considering that reductions in muscle power and strength are, at least in part, related to preferential type II myoﬁbre atrophy [66]. For example, a study by Charette and colleagues found that a 12-week resistance training program in older women (mean age 69 years ± 1 year) signiﬁcantly increased the cross-sectional area of the type II muscle ﬁbers in comparison with an educational control group [61]. In another study, Fiatarone and colleagues examined the eﬀects of an 8-week, high- intensity resistance program in ten frail, institutionalized older adults (90 years ± 1 year). The researchers found that mid-thigh muscle area increased by 9.0% ± 4.5% and that mean tandem gait speed improved by 48% [62]. In addition, participants had an average strength gain of 174%. In another recent study, Ferri and colleagues assessed changes in muscle strength and power following a 16-week resistance program in a population of men between the ages of 65 and 81. The researchers found not only an increase in maximal force production but also a signiﬁcant increase in muscle power [63]. These studies provide compelling evidence that a progressive resistance training program can reduce muscle atrophy, improve gait speed, and increase muscle power. Combination exercise training programs are often used to meet the current physical activity recommendations by the ACSM/AHA which state that older adults should take a multifactorial approach to enhancing physical activity by performing aerobic, strength, and ﬂexibility exercise. Find- ings from recent trials support the eﬃcacy of interventions that incorporate both aerobic and resistance training (with or without dietary intervention) for improving physical function in obese, older adults [55]. Another recent clinical trial sought to determine whether combining aerobic and resistance exercise compared to either modality alone (i.e., combination versus aerobic exercise alone versus resistance exercise alone) would exert greater eﬀects on risk factors for disease and disability [67]. Abdominally obese older men and women completed a six-month intervention consisting of either resistance exercise three times per week, aerobic exercise (treadmill walking) ﬁve times per week, resistance and aerobic exercise three times per week, or a nonexer- cise control. All intervention groups showed improvements in functional limitations; however, this improvement was greater for the combined exercise group compared to the aerobic-only exercise group. Furthermore, the combined and aerobic-only groups lost signiﬁcantly more total fat and abdominal fat than the control and resistance-only 5 group, while skeletal muscle mass was most improved in the combined and resistance exercise group. However, there is contradictory information presented by Manini and colleagues that demonstrated that one year of aerobic and resistance exercise performed two times per week was ineﬀective at improving long-distance walking speed in obese men and women when compared to nonobese [68]. Despite little change in long-distance walking speed (400 meters), obese individuals did manage to gain clinically signiﬁcant improvements in a short performance battery of physical function that includes chair rises, balance tests, and 4-meter walking test. The most recent data by Villareal and colleagues help to conﬁrm the independent eﬀects of exercise (aerobic + resis- tance exercise) on mobility and physical function in obese men and women [55]. In this study, exercise alone (3 times per week) resulted in signiﬁcant improvements in a battery of functional tasks that included walking 50 feet, climbing one ﬂight of stairs, and performance on a Romberg balance test—a motor coordination test that requires subjects to maintain static balance under progressively more diﬃcult altered base of support conditions. Additional functional tasks that improved in the Villareal study included putting on and removing a coat, picking up a penny, standing up from a chair, and lifting a book. Collectively, these eﬀects were greater than a concurrent control group and exceeded the improvements in a group who completed a diet-only intervention. Collectively, these studies suggest that exercise alone can have robust eﬀects on physical function in obese, older adults. However, these eﬀects might not exceed those found with nonobese individuals. Therefore, an exercise program combining aerobic and resistance exercise provides the most beneﬁcial health eﬀects in obese older adults. 4.3. Multicomponent Interventions. Many lifestyle interven- tions designed to improve physical function in obese, older adults have typically included both a dietary component and a physical activity program, and thus can be classiﬁed as a multicomponent intervention. Because studies that intervene with caloric restriction plus exercise generally demonstrate beneﬁcial eﬀects on long-distance walking ability [4], a mul- ticomponent intervention that includes caloric restriction may be needed to optimize the beneﬁts of moderate intensity physical activity in obese, older adults. A relatively small number of studies have examined the eﬀects of multicom- ponent interventions that combine dietary restriction plus exercise in obese, older adults. Findings from recent trials support the eﬀectiveness of multicomponent (i.e., diet plus aerobic plus resistance exercise) interventions for improving mobility function in obese, older adults. For example, the addition of resistance training to a diet plus aerobic exercise program can attenuate the loss of skeletal muscle during weight loss in adults aged 65 and older [69]. Diet plus supervised resistance and aerobic exercise regimens have also been found to substantially improve mobility (i.e., walking speed) and