The Effects of Aerobic and Muscular Endurance Based Resistance Exercises on the Cardiorespiratory System in College Age Females

The purpose of this study was to evaluate the cardiorespiratory response in college age females, between the ages of 19 and 24, before and after participating in a six week moderate-vigorous aerobic exercise program compared to a six week moderate-vigorous aerobic exercise program combined with a muscular endurance based resistance training program. Specifically, which mode of exercise has the most significant effect on cardiorespiratory fitness? Methods: Twelve sedentary college age females between the ages of 19 to 24 years, with a mean age of 20.9 years, participated in the study. Eligible participants were randomly assigned to one of three groups: an aerobic exercise only group (n=5), a combination of aerobic exercise and muscular endurance based resistance training group (n=3), and a control group (n=4). Subjects in the aerobic exercise only group participated in a six week program of moderate-vigorous aerobic exercise at 60-75% of their measured target heart rate reserve for a total of 50 minutes, three days per week. Subjects in the combination exercise group participated in a six week program of aerobic exercise at 60-75% of their measured target heart rate reserve for 30 minutes, in addition to a muscular endurance based resistance training program, three days per week. Subjects in the control group were asked to refrain from exercise during the six week period. Anthropometric measurements and cardiorespiratory fitness were assessed pre- and post-training period. Cardiorespiratory fitness was assessed through graded exercise testing (Bruce protocol) and continuous pulmonary gas exchange and indirect calorimetry. Results: A mixed ANOVA analysis (p\u3c0.05) showed no significant difference between maximal VO2 measurements in regard to time and group (p=0.50). A paired samples t-test further showed no significant difference between the pre- and post-training measurements in maximal VO2 (p=0.162). A second mixed ANOVA analysis (p\u3c0.05) showed no significant difference between measured HRmax in regard to time and the experimental group (p=0.113). A paired samples t-test further showed no significant difference between the pre- and post-training measurements in maximal heart rate (p=0.892). Conclusion: In sedentary females, between the ages of 19 and 24, six weeks of moderate-vigorous aerobic exercise plus muscular endurance resistance training elicited no significant difference from six weeks of moderate-vigorous aerobic exercise alone, in regard to the effects on cardiorespiratory fitness. The findings of this study were not in agreement with the suggestion that combination training has a greater impact on the components of cardiorespiratory endurance than aerobic exercise alone. However, the suggestion that no significant change would occur over an extended period of time within sedentary females who had no alteration in physical activity level was supported. Furthermore, in order to elicit a change in cardiorespiratory fitness, physical activity level must be positively altered