THE EFFECTS OF TAI CHI, RESISTANCE TRAINING, AND DIET ON PHYSICAL FUNCTION IN OBESE OLDER WOMEN

BACKGROUND: The increased prevalence of obesity and function limitations associated with aging are major public health problems in the U.S. The risk of developing obesity and functional limitations is higher in minority populations living in urban settings and previous research has shown that Tai Chi, resistance training, and diet individually result in increased levels of physical function and facilitate healthy weight loss. However, the combination of these specific interventions has yet to be examined in obese older women in an urban setting. PURPOSE: The purpose of this study is to examine a combined resistance training (RT), Tai Chi, and a behaviorally-based dietary intervention on physical function. METHODS: Using a non-randomized design, 28 obese women (65.2 ± 8.1 yr) completed a 12-week intervention; participants were assigned to an intervention group (EXD, BMI = 38.83 ± 5.06) or a control group (CON, BMI = 36.57 ± 3.39). The EXD group (n = 19) participated in Tai Chi three times per week for 45 minutes, RT twice per week for 45 minutes (2-3 sets, 10-15 reps), and a dietary session using a modified Dietary Approaches to Stop Hypertension Diet once per week for 45 minutes. The CON group (n = 9) was asked to continue their normal lifestyle. Outcomes measured were the short physical performance battery (SPPB), the timed up and go (TUG), chair-sit and reach to measure flexibility, and leg and grip strength. Analysis of covariance (ANCOVA) was used for between-group comparisons adjusted for baseline values. RESULTS: TUG time was significantly reduced by 0.64 ± 2.1 sec (p = 0.04) in the EXD group while the CON group saw a significant increase of 0.71 sec (p = 0.051). Flexibility measurements improved by 2.31 ± 5.4 cm in the EXD group (p = 0.08), however, the CON group saw no significant changes from baseline (1.69 cm ± 6.97; p = 0.51). CONCLUSION: Tai Chi, RT, and dietary changes helped improve performance on TUG time and flexibility, but there were no statistically significant increases in muscle strength measures or SPPB scores. Further research should be conducted using this combination of interventions with a larger sample size to verify these findings.


INTRODUCTION
The prevalence of obesity, defined as a body mass index (BMI) greater than 30 kg/m 2 , has doubled in the past 10 years in the general population and estimates indicate that 35% of adults over the age of 65 are obese in the U.S. (13). Obese individuals are at a much greater risk of developing health conditions including hypertension, cardiovascular disease, diabetes and some forms of cancer (27,2).
Previous research (29) has shown that women have a higher prevalence rate of obesity compared to men, and the prevalence rates of obesity greatly differ across different racial groups. Over the age of 60 yrs, the prevalence rates of obesity for non-Hispanic white women, non-Hispanic Black women, Hispanic women, and non-Hispanic Asian women are 32.8%, 56.6%, 44.4%, and 11.4% respectively (13). In older women, obesity intensifies the decline of physical function that is associated with aging (3).
An exercise form effective in treating obesity is resistance training (RT), and RT has been shown to improve muscle strength, physical function, and can promote weight loss (22,11,28,15). Resistance training can also be performed with little risk of injury to the subjects (28,15). Resistance training programs in minority women have resulted in significant improvements in muscular strength, along with physical function (31,28). However, RT is not considered an aerobic activity, Tai Chi exercise however, results in significant improvements in physical function in obese older adults and compares to aerobic activities (21). Previous Tai Chi interventions have resulted in significant improvements in physical function measures, and facilitates weight loss (1,20,22,36,37,25). Tai Chi has also been found to have a very high adherence rate in the older adults due to its low risk of injury (23,37). Combining a dietary intervention with an exercise program has been shown to significantly improve physical function in obese older women (9,3,39,6).
Previous research has shown that the Dietary Approach to Stop Hypertension (DASH) diet improves total diet quality, blood pressure, and can result in moderate weight loss (4,9,10). The DASH diet has been shown to be an effective and reliable intervention tool in obese older adults, and significant improvements occur in physical function and muscle strength when the DASH diet is combined with an exercise program (9,6,34). Furthermore, previous research has shown that the modified DASH diet combined with exercise results in significant decreases in fat mass and results in significant weight loss (6,21).
There have been numerous studies that show that combining exercise forms with a dietary intervention results in improved physical function and muscle strength (33,3,39,6,21). However, there is a lack of studies that examine Tai Chi and RT in combination with dietary changes in an urban setting. A study combining these individually demonstrated interventions has not been evaluated in obese older minority women. Thus the purpose of this study is to examine the effects of Tai Chi, diet, and RT in obese older women on measures of physical and muscle strength.

Study Design
This study used a quasi-experimental, pre-and post-measures design to study changes in the primary and exploratory outcome measures. The intervention consisted of a 12 week design with a control group to examine changes and to be used as a

Subjects
The women living in the surrounding communities (within 1 mile of the senior center) were recruited for this study. Flyers, press releases to local newspapers, and "word-of-mouth" at the local senior center were utilized as recruiting techniques.
After the first contact from potential subjects, a brief medical and background history survey was completed over the telephone to establish eligibility for the study. After this initial telephone interview, all eligible subjects attended a short orientation session to learn more about the study, which served as another recruitment strategy. After the short orientation took place, the potential subjects who were interested and qualified for the study were invited to a baseline assessment session. The criteria for eligibility included: 1) women ages 50 -80 years old, 2) BMI of 30.0 to 50.0 kg/m², 3) currently (within past 6 months) not involved in an exercise program, and 4) post menopausal via self report. The exclusionary criteria included: 1) failure to provide informed consent, 2) significant or suspected cognitive impairment, 3) severe hearing loss, speech disorder, language barrier or visual impairment, 4) progressive, degenerative neurologic disease, 5) terminal illness with life expectancy of < 12 months as determined by physician, 6) sever pulmonary disease, uncontrolled diabetes, blood pressure or anemia, 7) medications not taken > 3 weeks, lipid lowering medications for >6 months, 8) major joint, vascular, abdominal, or thoracic injury within 6 months, 9) significant cardiovascular disease, and 10) inability to safely engage in exercise. A total of 33 subjects were initially recruited to be a part of the study. A total of six participants dropped out of the intervention group (one withdrew because of travel, one withdrew because sessions were too early in the day, one withdrew because of gallstones, one withdrew due to the exercise "being too easy", and two subjects could not be contacted for post-testing). A total of one participant withdrew due to lack of follow-up in the control group. This resulted in a total of 26 participants as the analytical sample.

Outcome Measures
Physical Function: The primary measure physical function was the timed up and go (TUG) test. The timed up and go test requires the subject to start in a seated position, walk 8 feet, and then return to a seated position. The time (sec) it takes to accomplish this task was recorded, the better of two times were taken for analysis.
The TUG test has been shown to be a valid predictor of falls and mobility of the older adult population (38). The TUG is a widely used measure of function, which makes the results generalizable, which is why the TUG was chosen as the primary variable.
Another measure of function was the short physical performance battery (SPPB). It includes a balance test, usual gait speed, and time chair stands. The balance test determines whether the subject can maintain a side by side stance, semitandem stance, and full tandem stance for 10 seconds each. The gait assessment test involves walking 4 meters at usual walking pace, which is repeated twice and the better (faster) of the two times (sec) taken. The timed chair stands test asks the subject to rise from a chair and sit from a chair 5 times as quick as they can with their arms crossed over their chest. Each test is scored from 0-4, with the best possible score being 4, and a maximum summary score of 12. The SPPB is a portable and reliable measure that has been shown to be a strong predictor of mortality and nursing home admissions (17).
Flexibility: The chair-sit-and-reach test is a measure of flexibility used in older adults (35). This test required the participant to sit on the edge of a chair with one knee bent and the other knee extended straight in front with the heel on the floor.
While keeping the leg straight, the participant reached down their leg attempting to reach for their toes. Participants were given a demonstration before completing the test and there was a practice trial followed by two trials (the best score was used for data analysis). The score was the number of centimeters short of reaching the toes (negative number) or beyond the toes (positive number).

Muscle Function and Strength: Grip strength is a valid and reliable method and
has been shown to be successful in measuring upper body strength in older adults (26).
Grip strength was measured using a hand-grip dynamometer (Jaymar Hydraulic Dynamometer, J.A. Preston, Corp., Jackson, MS). The test was performed in subject's non-dominated hand and the best of 3 scores was utilized for scoring. The hand dynamometer is considered to be a very reliable tool and can be done with little or no risk for the subjects (8).
Leg strength was determined by using a handheld manual muscle dynamometer (Nicholas Manual Muscle Tester -Lafayette Instrument Company).
The manual muscle tester has been found to be a good method in determining strength and in all individuals (14). The device has been successful in determining strength in the older adult population and it is a portable, easy to use device (34). Knee extensor strength was measured as the peak amount of force that the examiner had to exert to break the isometric contraction. This break in the contraction is indicated by a small movement of the subject's dominant leg in the opposite direction of the movement exerted by the researcher. The value recorded was leg extensor torque (kg-m) in order to account for variations in leg length.
Anthropometrics: Height and weight were measured with a stadiometer (Webb City, MO, USA) to calculate BMI and were following a 12 hour fast. Waist and hip measures were determined by utilizing a standard tape measure with an attached tensometer. Body composition was measured using a simple foot-to-foot bioelectrical impedance device (Tanita BF-556). The device estimates fat mass and percent body fat using electrical currents. This test has been shown to be a valid and reliable measure of body composition while having few associated risks (30).
Other Measures: The subjects were asked to complete surveys about physical activity levels and dietary quality. The Yale Physical Activity Survey was used to estimate energy expenditure per week and time spent performing physical activity (40). Dietary quality and patterns were measured using the Dietary Screening Tool (DST). The DST was created to assess general health and nutrition status through the quality and patterns of diets among older adults (7). Scores of the DST correspond to nutrition risk and were utilized in the diet education intervention.

Group Assignment
Since this project was a translational, community outreach program designed for benefiting the subjects, randomization of groups did not occur. After baseline testing was completed, subjects were placed into groups by the order in which they finished testing. Due to the limited space at the local senior center, there was a limit on how many subjects could be placed in the Intervention Group (EXD). Those subjects who wished to be involved in the study were asked to be in the waitlist control group (CON). The EXD group received all three aspects of the intervention, while the CON group was asked to maintain their normal lifestyle.

DASH Dietary Education Intervention:
A 45-minute behaviorally-based dietary education session was held once a week for the 12 week intervention period, and were led by a registered dietitian. A modified DASH-based diet was used as the diet plan and has been shown to have a high compliance rate with older adults (9,4).
The goals of the diet include lowering intake of saturated fat (≤ 7% of caloric intake) and achieving a moderate intake of total fat (≤ 35% of caloric intake). We modified the intake of total fat from 27% to 35% to allow for increased intake of healthy unsaturated fats. The diet also encourages high intake of fresh fruits, vegetables, and whole grains; consumption of low-fat dairy and meat products; moderate intake of sodium  (2). Each session included approximately 45 minutes using elastic tubing that allows the body to move through uninhibited range of motion, which may help avoid musculoskeletal injuries (31). RT programs utilizing elastic tubing can be used as a practical and effect method of achieving strength gains in older adults (31). Seven total upper and lower body exercises for major muscles were done with 1-3 sets of 10-15 repetitions for each exercise. The goal was for the exercise intensity to be moderate, which has been demonstrated to have positive effects on physical functioning in older adults (34). Intensity was determined by the band color used by the subject and the Borg RPE scale. The Borg RPE scale is a subjective rating of perceived exertion scale that ranges from 6 -20, the number 6 correlates to low difficulty and the number 20 is used to express maximal exertion.

Statistical Analysis
The EXD group sample number (n = 25) was chosen because of practical reasons, as the center only has room for 25 subjects to safely participate in the exercise program. Additionally, in order to determine our sample size requirement to achieve significant results, a sample size test was conducted. Estimating that subjects in the EXD group will gain improvements in the timed up and go (TUG) test by 1.5 (1.2) seconds and with no change in the control group, the required sample size for significance is 12 subjects in each group. This will result in a statistical power of .82 for the projected study findings with an alpha set at 0.05.
To assess our main hypothesis, the changes from baseline descriptive measures were analyzed to define differences between the groups (EXD group and CON group).
First, an Independent Samples T-Test was used to test if the two samples were drawn  from the same population by comparing the two means on baseline measures. Next,   the Shapiro Wilk test was used to determine if the data for the changes in the primary   and exploratory outcome variables are normally distributed. The primary variable was   the TUG test, and the exploratory variables were grip strength, leg strength, and flexibility. If the data were normally distributed a paired T-Test was run to examine within-group changes from baseline for the major outcome variables. If the data were not normally distributed a nonparametric equivalent was used, the signed rank test.
Following that test, an analysis was conducted in the data to determine outliers in the primary outcome data, with outliers defined as a data point 3 deviations higher or lower than the mean. An analysis of covariance was utilized to examine the pre-post changes in the primary and exploratory outcome variables between the two groups, which was adjusted for the baseline values of the primary and exploratory variables, as well as potential confounders. After these analyses were completed, a separate analysis was run to compare changes in good attenders versus poor attenders in the EXD group; good attenders were defined as having an attendance greater than 60%, and the analysis of covariance was used to examine these changes. Figure 1 depicts the flow of participants that took place throughout the study.

RESULTS
The total analytic sample consisted of 26 participants, with 17 in the EXD group (BMI = 38.8 kg/m2) and 9 in the CON group (BMI = 36.6 kg/m2). There was only one significant difference between the subjects who dropped out of the study compared to those who completed, the dropouts had a smaller waist circumference when compared to the completers (p = 0.036). The average attendance for all aspects of the intervention sessions was 67.5%, and greater than 69% for the dietary sessions in the EXD group. The CON group experienced a decline in total diet quality of -6.1 (SD = 7.2), and the EXD group improved diet quality by 2.2 (SD = 10.7). Table 2 shows the changes that occurred from baseline to 12 weeks in both groups. There were significant within-group changes in TUG time in both the EXD and CON groups, as the EXD group saw an improvement of 0.6 (SD = 2.1) sec after the 12-week intervention (p = 0.04) and the CON group saw a decline of 0.7 (SD = 0.9) seconds with the 12-week intervention (p = 0.05). Although both groups experienced significant within-group changes, there were no significant betweengroup differences in TUG time change (p = 0.104).
Along with TUG time change, the EXD showed a tendency for an improvement in measures of flexibility with an improvement of 2.3 (SD = 5.4) cm with the 12-week intervention (p = 0.07), while the CON group did not significantly change (p = 0.51). There was not a significant between-group difference regarding flexibility change. There were no significant changes that occurred after baseline in SPPB scores, leg strength, or grip strength for either group.
Due to the variations in attendance percentage, a separate analysis was designed to examine post-intervention changes between good attenders (n = 12) and poor attenders (n = 5) within the EXD group to assess the efficacy of the intervention.
Good attenders were defined as having an attendance ≥ 60% to the intervention sessions. There was only one significant difference between the good attenders and the poor attenders at baseline; the poor attenders had a higher time measure for the chair stand test (p = 0.054). There were also significant within-group changes as the good attenders significantly improved TUG time by 0.8 (SD = 0.7) seconds (p = 0.003), but the poor attender group did not experience any significant changes (p = 0.893). There were no significant differences within or between-groups in flexibility, grip strength, knee extensor torque, or SPPB scores.

DISCUSSION
The major finding of the study, and in support of our hypothesis, was that with a 12-week intervention of combined of Tai Chi, RT, and diet resulted in significant improvements in selected measures of mobility and flexibility in obese older women in an urban setting. To our knowledge, the current study is the first to test the combined interventions of Tai Chi, RT, and diet in obese older minority women living in a community setting.
The major finding of this study was that TUG performance improved in the EXD group by 5.7%, while a CON group declined by 8.7%. These data support the original hypothesis that TUG time would significantly improve with the 12-week intervention. A major finding of this study that was not in support our hypothesis, is that measures of muscle strength did not significantly improve in the EXD group.
This was an unexpected result because previous research has shown improvements in muscle strength after similar interventions in community settings (31,34).
Additionally, the results indicate that the EXD group had a tendency to improve flexibility, as the subjects in the EXD group improved in flexibility measures by 24% after baseline. This improvement was also demonstrated in previous studies combining Tai Chi and diet modification (5,21).
The TUG is a valid predictor of fall risk and is a streamlined measure that can predict overall levels of physical function (38). These findings in TUG improvement confirm the results of the study conducted by Intarakamhang et al. (20). That Tai Chi intervention consisted of 14 older females and took place over 12 weeks. The results from that study demonstrated improvements in the TUG by 1.38 seconds (p < 0.001).
Tai Chi alone, and Tai Chi combined with other interventions has been shown to result in positive improvements in function (20,21,23). These changes in TUG time could be attributed to improved proprioception, and improved flexibility and strength of the muscles in the leg and trunk (9).
The findings of the current study in flexibility are similar in comparison to the findings from a previous study by Katkowski et al. (21). That previous study utilized After the data analysis based on attendance was performed, the significant change in TUG time that was observed in the good attenders (.80 seconds) was greater than previous studies with intervention groups incorporating the DASH diet with Tai Chi (21), and DASH diet with resistance training (34). The significant difference between groups at baseline in the chair stand test did not attribute to an overall difference in the SPPB total score. These data suggest that when participants attended the majority of combined intervention sessions, a significant improvement occurred in measures of physical function. It has been shown that it is difficult to promote consistent participation in community studies (24). However, community interventions ultimately need to be evaluated based on how all of the subjects improved as a group, not only through those who adhered to the program. Improving adherence rates should be a major focus in future studies using this setting and population.
This study adds to current literature on the effects of combined exercise and dietary interventions. This is also, the first study to combine RT, Tai Chi, and dietary changes in obese older women. The findings from the current study confirm those findings in previous studies in obese older women regarding the TUG test and flexibility measures (21,33). However, the studies done in obese older women (33,21) did not incorporate minority women as a major part of their study population. A study done by Rogers et al. (31) included minority women and took place in a community setting over 4 weeks. The results of machine-based resistance training program showed improved lower body, and upper body strength by 20% and 24%, respectively (p < 0.05). However, that study did result in significant improvements in function that was in contrast to the improvements in function found in the current study. The current study fills the gap in current literature by incorporating this minority population and by combining multiple intervention strategies into one program.
There are several strengths of this study. First, a primary strength was the inclusion of minority women (84% non-white women). There is a lack of studies that have examined exercise and dietary interventions in older obese minority women.
Those few studies (31,21,34) that included minority women did not use the current study's combined intervention strategies in this population or setting. Second, the current study also included a waitlist control group that was used as a comparison and to strengthen the study design. The waitlist control group allowed for an analysis to occur to effectively evaluate the impact of the intervention. Third, this study utilized well-validated measures of physical function in older adults. The SPPB is a valid test that can evaluate function of the lower extremity and can predict disability in older adults (18,16). Moreover, an SPPB score below 9 is defined as functionally limited and sedentary (17) and this is significant as the baseline SPPB scores in the EXD group was 8.4 (SD = 2.5), and the average score for the CON at baseline was 8.9 (SD = 2.9). These values demonstrate that the groups in our study had a below average level of function and thus this population is ideal for conduction interventions to improve function.

Introduction
Obesity is a growing health problem and is associated with increased risk of coronary heart disease, type 2 diabetes, some cancers, hypertension, and sarcopenia [1,2,3,4] The prevalence rate of obesity, defined as a body mass index (BMI) greater than 30 kg/m 2 , is 35% in women older than 60 years of age [1,3]. Along with higher rates of obesity, older women are also at a greater risk of developing an age-related decline in muscle strength, also known as sarcopenia [1]. Both of these conditions result in significant disability in older adults, and leads to an impaired mobility.
However, resistance training and Tai Chi have been found to increase strength, improve cardiovascular fitness, and result in moderate weight loss in older women on their own [4,5,6,7,8]. Changes in dietary quality have been associated with moderate weight loss and is considered an effective intervention tool for obese individuals [1,7,9].
The purpose of this literature review is to examine the consequences and treatments of obesity and how they are associated with physical and muscle function in older women. This literature review will also detail current research evidence regarding the use of diet, Tai Chi, and resistance training as intervention strategies, and when all of these interventions are combined.

Obesity in Older Adults
The prevalence of obesity has doubled in the past 10 years in the general population and estimates indicate that 37% of adults over the age of 65 are obese [1].
Recent research has shown that these obese individuals are at a much greater risk of developing health conditions that include hypertension, cardiovascular disease, diabetes and forms of cancer [1,2,3.4]. Mathus-Vliegen et al. [1] discovered that morbidity and mortality associated with obesity and overweight individuals increases at a BMI greater than 30 kg/m2. Consequently, these obese individuals should be targeted with treatment strategies in order to initiate weight loss. The majority of these obese individuals also have functional impairments, obesity-related diseases, and metabolic complications that are all significantly improved by weight loss.
Obesity is associated with greater risks of developing many chronic diseases and conditions. Must et al. [10] examined the association between being obese and the development of numerous diseases, using data from the Third National Health and black women becoming more susceptible to metabolic syndrome and the development of coronary heart disease, which causes concern for health professionals.
In conclusion, the prevalence of obesity is significantly higher in older women and as a result, these older women are at a greater risk of developing the comorbid conditions of obesity. These obese older women are a high-risk population and possible intervention strategies should be examined. Along with older women at a higher risk, minority older women seem to have a significantly higher risk of developing obesity. The data gathered from these studies supports that older women and older minority women are at an increased need for intervention strategies that target obesity.

Obesity and Aging on Physical Function in Older Women
Along with higher risks for developing obesity and sarcopenia, the older adult population also can experience a decrease in overall physical function. This decline has the potential to vary depending on race or other factors. Thorpe et al. [13] researched the decline in physical function and how it's associated with race. The data were collected from 2,969 black and white subjects who were between the ages of 70

Obesity and Aging on Muscle Function in Older Women
Obesity is accompanied by another condition that is associated with aging and can lead to decreased mobility and increased fall risk. There is a loss of muscle mass that occurs as a result of the aging process, and is called sarcopenia. This is caused because skeletal muscle is very adaptable and changes over time due to aging, inactivity, or exercise level. As shown in a review by Thompson [19], muscle mass decreases by approximately 25 -35% from peak values observed at younger ages (25 -35 years old) when an individual reaches old age. Decreases in muscle fiber number, size, and muscle fiber recruitment contribute to this loss of muscle mass.
Inactivity results in atrophy of postural muscles that are not utilized on a regular basis (i.e. anti-gravity muscles). The inactive older adult has increased risks for muscle atrophy and decreased function or disability. This portrays the importance of physical activity for older adults in order to prevent this loss of muscle mass. Overall more studies are needed to define the relationship between age and muscle loss to determine the best prevention and rehabilitation strategy.
The loss of muscle mass associated with aging can also cause pain in joints such as the knee or ankle, which corresponds to a decreased level of physical function in the elderly. Goodpaster et al. [20] examined the associations between loss of muscle mass and knee pain in older adults. There were 858 subjects who were between the ages of 70 -79 that were recruited from the Health, Aging, and Body Composition Study. Muscle quality and mass was measured by using computed tomography (CT) and dual-energy X-ray absorptiometry (DEXA) scans and the strength of the quadriceps was measured isokinetically by using a handheld manual muscle tester. The subjects were placed into two different groups, individuals who were experiencing pain in one group, and pain free individuals were placed into group two. The average BMI of the subjects was 27.9 ± 4.8 kg/m2. Subjects who were experiencing knee pain had significantly lower muscle torque (p < 0.001), indicating a lower muscle quality than the individuals not experience pain. Muscle quality was found to be significantly lower in subjects who had osteoarthritis and/or pain when compared to healthy older adults. This pain associated sarcopenia influences muscle strength and muscle quality in the older adult population.
Comparing muscle across different age groups can examine the decline of muscle, which was the goal of the study conducted by Hiroshi et al. [21]. The study had a total of 164 subjects who were placed into 5 different groups according to their ages. The age groups were 20 -39 yrs, 40s, 50s, 60s, and 70s. The methods in which the study examined strength were isokinetic knee extensor and flexor peak torque, and the cross sectional area (CSA) of the quadriceps femoris muscle. The results of the study show that over time, peak torque was inversely related to age in both women and men. The speed of contraction also decreased from .799 -.756 seconds for men, and .639 -.530 in women (p < 0.001). A significant correlation was found between the CSA of the quadriceps and peak torque values in both men and women. The correlation was .827 in men (p < 0.001) and .657 in women (p < 0.¬001). This demonstrates that muscle function and strength decline with age; however, muscle mass also decreases over time. This loss of muscle mass can be an influencing factor in the loss of muscle strength. The results of this study demonstrate that muscle strength losses can be due to the loss of muscle mass associated with aging. The decline in muscle function can also be related to the speed of contraction and recruitment of muscle fibers. Muscle mass and function decline as a result of the aging process, however, there is a relationship between obesity and muscle strength.
The association between obesity and handgrip strength was measured in the study conducted by Stenholm et al. [22]. The study was designed to discover the relationship between history of obesity and muscle strength. Obesity and aging have significant effects on physical function and muscle function in the older adult population. These significant effects result in impaired mobility, increased fall risk, and decreases the independence of the older adult population. Obesity is also a major risk factor in numerous chronic diseases and conditions, which can include hypertension, diabetes, coronary heart disease, and some cancers. The number of older adults is expected to increase and the prevalence rates of obesity are not declining. Obesity is a major health problem and possible treatment methods should be explored and established.

Treatments of Obesity
Obesity is a major health problem and the prevalence of obesity is increasing.
Obesity is a risk factor for numerous diseases and conditions that include coronary heart disease, hypertension, and some cancers [1,2,3,4]. As individuals age, their risk of developing obesity increases and this can lead to declines in overall health. These include decreases in physical functioning and muscle strength. The primary treatments of obesity include a low calorie diet, increased levels of physical activity, behavior therapy, pharmacological therapy, and surgery options [3]. Increased levels of physical activity and diet modifications can result in significant weight loss. A 5 -10 % reduction in weight can improve blood pressure, cholesterol, glycemic control, and reduce obesity. Diet and exercise seem the most plausible actions due to their low risk of complications, the associated improvements in health, and the low cost of adopting an exercise and diet program.

Diet and Older adults
Obesity causes many serious medical complications and diseases that can Throughout the weight loss process, the intake of nutrients should be significantly evaluated. The goal of the study by Miller [25] was to examine the nutrient intake in older obese adults throughout a weight loss study. The study included a total of 71 subjects who were an average age of 69.5 years (± 5.8). The weight loss occurred for 6 months and utilized partial meal replacements, and the goal was to reduce 10% of starting weight. The results of the study showed that subjects in the weight loss group decreased body weight by an average of 8.8% (± 0.4). The daily average caloric intake was significantly lower in the weight loss group; 1396 (± 64) kcals, when compared to the control groups 1817 (± 71) kcals. The study also recorded that key micronutrients (calcium, vitamin D, iron, vitamin C, vitamin E) were higher in the weight loss group.  [29]. The DASH diet is a diet that is mainly used to influence total diet quality and is used to result in weight loss and improved blood pressure. The goals of the diet include lowering intake of saturated fat (≤ 7% of caloric intake) and achieving a moderate intake of total fat (≤ 35% of caloric intake) [30]. The diet also encourages high intake of fresh fruits, vegetables, and whole grains; consumption of low-fat dairy and meat products; and a moderate intake of sodium (3,000 mg or less/day) [30]. The DASH diet has been shown to be an effective intervention tool when working with the older adult population [29,30,31]. This modified DASH diet is designed to alter the intake of total fat from 27% to 35% to allow for intake of healthy unsaturated fats.

DASH Diet and Older Adults
Obesity can result in hypertension, or chronic high blood pressure.
Hypertension can lead to cardiovascular disease and is most effectively prevented and treated through diet and exercise. The DASH diet is a diet plan that can be used to result in weight loss and improve blood pressure. The study done by Appel et al. [29] utilized a clinical trial in order to determine the DASH diet's effect on blood pressure.
The study included 459 adults who had a systolic blood pressure less than 160 mm Hg, and a diastolic blood pressure of 80 -95 mm Hg. After the 11 week time period, the subjects improved their systolic blood pressure by 5.5 mm Hg, and their diastolic blood pressure by 3 mm Hg (p < 0.001). The subjects who were hypertensive before the study took place had a larger decrease in blood pressure after the study. The 133 subjects with hypertension reduced systolic blood pressure by 16 Combining the DASH diet with an exercise program resulted in significant weight loss and improvements in insulin sensitivity and lipids. This study only focused on overweight men and women, and did not study individuals regarding physical function or the effects of the DASH diet on those with chronic disease.
The DASH diet has been shown to result in weight loss and reduce hypertension, however, these results have not been shown in individuals who have chronic conditions such as metabolic syndrome [32]. Metabolic syndrome is a collection of metabolic risk factors for cardiovascular disease and type 2 diabetes [32].
The goal of the study done by Shenoy and colleagues [32]  Weight management is the primary method of treating obesity, however it is important during weight loss to minimize the loss of lean mass. The study by Newman et al. [35] was conducted to evaluate the relation between weight loss or weight gain with changes in lean mass in older adults. The study included 2,163 men and women between the ages of 70-79 yrs, and the data were collected over a 4-year period and was taken from the Health, Aging, and Body Composition Study. The study results showed that in older men and women, there was a significant loss of lean mass that occurred with weight loss. These results were even more significant when subjects were involved with a hospital stay. This study portrays the importance to maintain lean mass when promoting weight loss, especially in older adults. Weight loss therapy should be designed to minimize muscle loss, and to maximize weight loss. Diet alone results in weight loss, improved physical function, and the DASH diet also significantly improves blood pressure measures. Previous studies [31,32,33] have shown that diet combined with exercise actually yields the greatest results in physical function, blood pressure, and can also influence weight loss [26,28]. Exercise and diet combined can result in weight loss and minimize loss of lean muscle, as well as improving physical function.

Exercise and Older Women
Physical activity and exercise have been shown to improve physical function [1], however, little is known about community based physical activity interventions.
The study conducted by Fitzpatrick et al. [36] examined the effects of a physical activity intervention in community centers in Georgia. There were a total of 418 older adults (83% female) included in the study, and the study spanned over a 4-month period. The physical activity program included chair exercise, and the promotion of walking outside the program (measured using pedometers), and function was measured by the SPPB. After the intervention was completed, the subjects improved physical function by 8.8% (p < 0.001) and increased physical activity minutes by 26% adult because of the low impact, and low risk of injury to the subjects [37,38].

Resistance Training and Older Adults
Resistance training is an exercise mode that results in significant improvements in muscular strength and endurance and could have greater effects in older adults. The goal of the study conducted by Krist et al. [37] was to examine the effects of resistance training on mobility and muscular strength. The resistance training program was designed to be progressive, or with increasing intensity over time. There were a total of ten subjects (6 women) who were all over the age of 77 years old and they were recruited from local nursing homes in Germany. Since the subjects were recruited from a nursing home it is assumed that they had impaired mobility. The exercise program spanned 8 weeks and resistance training exercises were completed twice a week. The exercises were completed using six different gym machines that were performed for 3 sets of 8 repetitions using the major muscle groups. The mobility of the subjects was assessed with the Elderly Mobility Scale There are many different forms and methods of resistance training that can be used by exercise professionals. One of the most common and easily transported is the use of elastic tubing or bands. These bands can allow full range of motion movements with resistance that can theoretically lower injury risk. The goal of the study performed by Mikesky et al. [38] was to evaluate the efficacy and adherence to a 12 week progressive resistance training program using elastic tubing. The study included a total of 55 (34 women) adults with an average age of 71.2 years old. The subjects were randomly assigned to an exercise group or a non-exercise control group. The exercises consisted of 3 sets of 10-12 repetitions that incorporated both upper and lower muscle groups. At the end of the study, 80.6% of the original subjects completed the program. Of these 80.6% however, adherence to the training session was an average of 90%. There were no significant changes between the two groups, however the exercise group significantly improved. Subjects in the exercise group increased strength by an average of 12% for knee extension, and 10% for knee flexion (p < 0.05). This study showed that elastic tubing resulted in significant strength gains and is a practical exercise tool for older adults. However, this study was not completed in an inner-city setting, nor did it include minority populations.
Due to the practicality of elastic tubing, they can used as an inexpensive exercise program for inner-city minority populations. The goal of the study conducted by Rogers et al. [39] was to determine the effects of elastic tubing on physical function Resistance training has been shown to significantly influence individual measures of physical function. However, the goal of Bouchard et al. [40] was to examine the effects of resistance training on an overall measure of physical function, physical capacity. The study included a total of 48 obese women who were between the ages of 55 to 75 years old. Physical capacity was measured with 11 different performance tests and scores ranged from 0 -44. Body composition was also measured through us of DEXA scans. The 48 obese women were randomly assigned to 4 groups, one with resistance training alone, resistance training combined with caloric restriction, caloric restriction alone, or a control group. The results of the study showed that body weight, fat mass, and BMI all significantly decreased in the caloric restriction, and the resistance training plus caloric restriction groups (p < 0.01).
However, the caloric restriction group saw a significant decrease in lean body mass after the 3 month time period (p < 0.05). The global physical capacity scored improved by an average of 10% (± 8.8) in the resistance training group compared to the control group (p < 0.01). The 3-month training program had a significant effect on physical capacity and when incorporated with caloric restriction diet, the subjects lost a significant amount of body weight. This study time frame spanned across three months, and consequently, future studies should examine the long term benefits of resistance training.
Resistance training has been shown to result in significant effects in short term studies, however, there has not been a long-term study that evaluated the effects of resistance training. The study performed by Flansbjer et al. [41] was designed to evaluate the long term effects of resistance training. The study included 18 men and women with an average age of 66 (± 4) years who were all chronic stroke patients.
The training group participated in resistance training sessions for the lower body Resistance training is a form of exercise that is believed to require a lot of expenditure and can be quite difficult for some individuals [42]. However the study performed by Brochu et al. [41] examined if disabled women with heart disease could perform resistance training at the required intensity to receive benefits. The study spanned 6 months and included 30 older women with coronary heart disease and were an average age of 70.6 (± 4.5) years old. The physical function measure was recorded via self report and consisted of 15 practical activities, and the resistance training program was performed using dumbbells and universal weights. After the intervention was complete, the resistance training improved their physical function score by 24%, on the contrary, the control group only improved by 3% (P = 0.007).
The resistance training group also significantly improved in measures of upper body and lower body strength (18 vs. 6%, and 29 vs. -2%, respectively). This study demonstrated that disabled older women can effectively participate in resistance training in order to result in significant gains of physical and muscle function.
Resistance training has been shown to increase muscle strength and help delay the onset of sarcopenia and other physical limitations. As shown from previous studies [36,37,38,39,40] resistance training increases muscle strength from external measurements, such as; bench press test, or isometric leg strength. The next study examined these variables as well as DXA scans to determine lean body mass. Botero et al. [43] researched this effect of resistance training on muscle strength and body composition with 23 post-menopausal women who were an average age of 60.02 years (± 4.42). The training program was administered for 12 months and consisted of periodization based resistance training that occurred twice a week. This exercise program consisted of 6-14 repetitions for 3 sets. The researchers found a significant increase in muscle strength and lean body mass, and also found decreases in body mass, body fat percentage and fat mass after the 12 month intervention period.
Resistance training can alter the effects of aging and decreases body fat in elderly women, however resistance training does not consistently result in improved balance, flexibility, and certain performance measures of function.
As stated above, the ACSM recommends that the exercise prescription for older adults should be multifaceted and should include different forms of exercise.
Resistance training is a form of exercise that is anaerobic and focuses primarily on strength and some physical function improvements. This creates the need for alternative exercises that focus on improving balance, flexibility, and physical function.

Tai Chi and Older Adults
A physical activity that focuses on these aspects is the Chinese martial art Tai Chi. Tai Chi is an exercise form that focuses on fluid motion and slow movements of the body that requires body control and balance. Tai Chi has a very high adherence rate in the older adult population due to its low impact of exercise and there is a low risk of injury for the subjects. Tai Chi is increasing in popularity and there have been recent studies that have demonstrated its effects in the older adult population. Tai Chi originated from China and is a martial art form that has been practiced for over 1200 years. The review performed by Adler et al. [44] described Tai  The brisk walking group and control group had a change of 0.2 (± 2.63) ml/kg/min, and -4.4 (± 2.63) ml/kg/min, respectively (p = 0.003, 0.08). The Tai Chi group also saw significant gains in non-dominant knee extensor strength, along with the single-leg stance test (p < 0.05). Tai Chi can be an effective way to improve many different functional fitness measures in elderly women. Tai Chi was also found to have elucidated greater results on these measures than the walking group. However, the main limitation of this study was that there was a lack of a true control group.
Tai Chi is becoming a favored exercise choice by researchers when they are working with older adults. The reasons for this are described in the review article written by Kuramoto [46]. Tai Chi is favored by researchers due to its low injury risk and it is equivalent to moderate or light intensity exercise. After examining the majority of Tai Chi studies from 1996 -2004 the researcher combined the conclusions from each study. Tai Chi has been found to reduce pain in patients with arthritis and osteoarthritis, and has been demonstrated to improve balance and reduce fall risk.
Improved aerobic capacity in all populations and blood pressure reductions were seen in myocardial infarction patients. Strength increases in the lower legs is also associated with Tai Chi participation. There is also qualitative data on the effects of Tai Chi that include improved quality of life, improved sleep quality, and stress reduction. Overall, Tai Chi is an effective exercise tool for older adults and can be used to improve aspects of health with low cost and low risk to the subjects. The subjects were all placed in the one intervention group with no control group.
After the 12-week intervention, balance scores in the right and left single leg stance test improved by 8.59 seconds and 5.85 seconds, respectfully (p < 0.001). There were also improvements in the timed up and go test, the subjects improved by 1.38 seconds The effects of Tai Chi can be seen on overall healthy adults, obese adults, and can also be seen in patients with chronic disease. Osteopenia is a chronic disease that is characterized by loss of bone mass due to the aging process. Osteopenia is a primary health concern for the elderly because individuals with osteopenia can break major bones from one minor fall. These major bones are the hip, spine, femur, and even the bones of the arm (when bracing a fall). Tai  Previous studies have shown that both Tai Chi and resistance training can significantly improve physical function and muscle strength [35 -42]

Exercise Combinations in Older Adults
The

Older Adults
The guidelines of the National Heart, Lung, and Blood Institute encourages of a loss of reduction in weight of 10% for those individuals who are obese. Donnelly and colleagues [54] wrote a position stand for the ACSM describing the intervention strategies for weight loss in adults. The authors described that regular physical activity (150 -300 min) may result in long-term weight loss for the obese adult. Physical function decline is greatly associated with high rates of obesity.
However, a weight loss program combined with moderate exercise could result in improved physical function and weight loss. Maintaining muscle strength is also an important factor as to reduce the chances of sarcopenic obesity occurring. The goal of the study by Anton et al. [54] was to evaluate a combination of exercise and weight management on physical function in older adults. The study included a total of 34 obese older (55 -79 years of age) adults that were randomly assigned to two different groups for the 24-week period. There was a weight loss plus exercise group, and an educational control group. The weight loss plus exercise group was involved in group based weight management sessions that met once a week, and an exercise program that met three times per week incorporating walking and lower body resistance training. The four major outcomes of the study were body weight, walking speed, knee extension strength, and the SPPB test. Scores on the SPPB improved in both exercise groups, and there were significant differences between groups (p = 0.02).
The exercise plus weight loss group lost significantly more weight when compared to 2.2 kg ± 0.9, Weight loss: 3.7 kg ± .9; p < 0.05). There were tendencies for significant results between groups for leg strength (p = 0.062), grip strength (p = 0.070), timed up and go test (p = 0.069), and fat free mass (p = 0.056). This study shows that Tai Chi results in significant weight loss when combined with a weight loss program. There are also trends that support that Tai Chi may have improved leg strength, grip strength, timed up and go test, and fat free mass. The results of this study showed trends of significant changes but the only statistically significant findings were weight loss and flexibility.
When weight loss occurs, there is a high risk of observing a decline in lean mass and muscle strength. This decline in lean body mass is referred to as sarcopenia and can cause impaired mobility in older adults. This portrays the importance of maintaining lean mass throughout weight loss. The review article by Delmonico et al.
[60] depicted the importance of resistance training during a weight loss intervention.
Although weight loss is recommended for overweight and obese adults to reduce risk of disease, exercise is a valuable addition to weight loss than can result in greater loss of weight and conservation of lean body mass. Resistance training is a well-known exercise modality that improves muscle strength and physical function. When combined with weight loss, resistance training has shown to be an effective method for the retention of lean body mas, improved physical function, and weight loss. The combination of intervention modalities elicits significant results, although, the longterm health benefits of resistance training and weight loss combined are unknown.

Conclusion
Obesity is a growing health problem and is a risk factor for numerous conditions and diseases that can lead to impaired mobility, decreased physical function, and deceased muscle strength. Older minority women have the greatest prevalence of obesity and are consequently, at greater risk of developing the diseases and conditions associated with obesity. The primary method to reduce the effects of obesity is to initiate weight loss through different modalities. However, throughout weight loss there can be negative effects on physical function and muscle strength.
Physical function and muscle strength are two key indicators of physical performance and are associated with overall quality of life. Changes in diet can results in significant weight loss; however, diet alone can result in a loss of lean mass as well.
Resistance training is an exercise modality that can be used to increase physical function, and aid in the conservation of lean body mass. Tai Chi is another exercise mode that is considered aerobic and has the same beneficial results when compared to walking. There have been very limited studies that have combined diet, resistance training, and Tai Chi as an intervention method. The studies that have looked at combined interventions have shown to illicit significant improvements in function and muscle strength. However, this combination has yet to be examined in older women, older minority women, and has yet to be done in a community setting.