Relationships among physical self-concept, physical activity and physical fitness in three different participant groups




Brewer, Wayne A.

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The overarching goals of this dissertation were accomplished in three distinct studies. The design of the first study is a descriptive study to determine in young adults the relationships among physical fitness, activity and self-concept; lower extremity strength and power; and physical self-concept. The correlations between the maximal aerobic physical performance measure and the Endurance and Activity subdomains of the PSDQ-S were moderately strong at r = 0.60 and r = 0.54, respectively. Low but significant relationships were found between VO2 max and the Sport subdomain (r = .35). Another significant and moderately strong correlation was found between the seated row and the Activity subdomain for the 3-RM/BW% (r = 0.64). The Strength subdomain measure significantly correlated with the 3-RM/BW% for the seated row (r = 0.35) and chest press (r = 0.43). The ACT and SP subdomains both demonstrated the greatest number of significant correlations with the strength physical performance measures. ACT demonstrated weak to moderate correlations with chest press (r = 0.40), seated row (r = 0.61), and QUAD180 (r = 0.34) SP was correlated with chest press (r = 0.40), seated row (r = 0.39), leg press (r = 0.33), and QUAD180 (r = 0.35.) For Global PSC and SE, only the quadriceps isokinetic measures yielded moderate but significant relationships (r = 0.33 and r = 0.37 for 60 and 180 degrees per second speeds, respectively). This study provided insight on the relationships between perceived competencies in the various domains of physical self-concept and objective measures of physical fitness. The Activity and Sport subdomains of physical self-concept were the best self-reported measures of physical fitness, while the seated row measure represented the best objective measure for overall physical fitness. The design of the second study was a case series consisting of three subjects. Baseline measures of physical self-concept, muscular and cardiovascular endurance, and physical activity levels were collected within 1 month of the conclusion of a previous research study that involved the same subjects for this study that received a 12-week supervised aerobic and resistance training program. These outcome measures were compared at the conclusion of the intervention to assess levels of effectiveness and compliance with the unsupervised home exercise program. The mean values of all the factors of the PSDQ-S were lower for all three subjects in this case report as compared to a reference population of 986 high school students from Australia. The two global factors of self-esteem and overall physical self-concept for two of the three subjects were lower than the reference group. The three subjects showed small decrements in muscular strength and cardiovascular endurance at baseline of the unsupervised study despite a washout period that ranged from 3-10 weeks between from the supervised intervention. Two subjects essentially maintained their VO2 max while the third subject had a large improvement (25%) at the conclusion of the unsupervised program from baseline. At the conclusion of the unsupervised program, only subject came close to meeting the Federal Physical Activity recommendations. The other two subjects lacked almost 400 minutes per week of recommended moderate to vigorous physical activity. The low self-reported physical activity levels for two of the subjects would suggest a much smaller expected change in aerobic capacity and muscle force generation than what actually occurred, thus a discrepancy existed between the self-reported physical activity and the physical fitness measures. The third study utilized a quasi-experimental design. The subjects were women referred to an Exercise and Education group (Ex + Ed); the comparison group were women who received a Diet-only (Diet) intervention. Education about proper diet and activity levels were provided to all participants. The Diet group received monthly education from their physician and a health educator. The Ex + Ed group received education from physical therapists and dieticians as part of their group intervention. Seventy-seven women enrolled in the Ex + Ed intervention and completed the baseline assessments. Twenty-three women completed the assessments at the conclusion of the 12-week intervention, resulting in a 71.1% attrition rate. At baseline, there were no differences in body weight between the women in Ex + Ed and Diet interventions. The women in the Diet group were significantly younger, had fewer co-morbidities and tended to be of Hispanic ethnicity. The ethnic make-up of the women in the Ex + Ed group was predominately African-American. The results of the 2 x 2 mixed model ANOVA revealed a significant group x time interaction (p = .02). The Diet group had a mean decrease in body weight of approximately 2.31 kg as compared to the Ex + Ed group with a mean decrease of 0.43 kg. Post hoc analysis with alpha set at .025 revealed a significant within-participants' effect for weight loss at the conclusion of the Diet intervention (p < .001). For the participants in the Ex + Ed intervention, significant improvements were made in the distance walked in six minutes and isometric load lifted for the squat and grip strength averages of both sides. The self-reported measures of physical self-concept and moderate PA improved significantly from baseline. Similar to previous studies, weight loss can be achieved easier by controlling caloric intake versus increasing caloric expenditure with exercise. Despite the absence of weight loss, improvements in physical fitness and physical self-perceptions can occur for obese women from low socio-economic backgrounds.



Aerobic physical performance, Physical performance measures, Physical Therapy