Abstract
The purpose of this study was to compare the activation of the rectus abdominis, external oblique abdominis, lower abdominal stabilizers, and lumbar erector spinae during performance of traditional exercises (i.e. abdominal crunch, side bridge, and quadruped) versus the Ab Circle device. The caloric expenditure during an absolute work level on a treadmill versus the Ab Circle was also investigated. Twelve volunteers (6 men, 6 women) between the ages of19 and 37 were recruited to participate in this study. Prior to the experiment, subjects attended one familiarization session during which demographic information (age, height, body mass) was recorded and body fat was assessed using the 3-site skin fold method (Jackson & Pollock, 1985). Subjects practiced at all three levels on the Ab Circle (ACl, AC2, AC3) dynamically for 5 minutes each. Technique for each of the traditional exercises was standardized and subjects performed multiple 15-second isometric actions for the abdominal crunch (CR), side bridge (SB), and quadruped (QP); all subjects were highly familiar with these exercises. Day one of data collection involved assessment of core muscle activity utilizing surface electromyography (EMG) to measure peripheral muscle activation. All subjects performed six exercise conditions (i.e. CR, SB, QP, ACl, AC2, and AC3) in randomized order. Day two of data collection involved assessment of caloric expenditure utilizing a lightweight portable metabolic measurement system (120xl 1Qx45 mm; 650 g) that uses breath-by-breath technology. Values of minute ventilation (VE, I/min), carbon dioxide production (VCO2, ml/min), and oxygen uptake (VO2, ml/min) were continuously monitored during all exercise modes (three Ab Circle levels and treadmill).Peripheral muscle activity of the RA, LAS, EO, LES was analyzed using surface EMG to test the hypothesis that the Ab Circle would elicit greater activation of all core muscles versus the traditional exercises. For the RA muscle, the CR exercise elicited significantly greater activity versus the Ab Circle level 1, and the SB exercise elicited significantly greater activity versus the Ab Circle levels 1 and 2. Significantly greater muscle activation of the EO occurred during the SB exercise versus the QP. Greater muscle activation of the LES occurred while exercising on the all three levels of the Ab Circle versus the CR. The SB and QP exercises also elicited greater LES activation versus the CR exercise. There were no other significant differences in muscle activity that were found between exercises. Caloric expenditure was assessed to test the hypothesis that caloric expenditure while on the Ab Circle would be greater versus the treadmill exercise. When evaluating caloric expenditure between TR walking and all three intensities on the Ab Circle, there were no significant differences between the exercises performed; therefore, caloric expenditure was similar between all three levels of the Ab Circle and TR walking.
Therefore, this investigation has shown that the Ab Circle is an effective device to moderately recruit several core muscle groups (RA, LAS, EO, LES) and can be an effective device for caloric expenditure. A great benefit to using the Ab Circle is the combination of simultaneous cardiovascular exercise and core muscle exercise in the same workout session.
| Date of Award | 2010 |
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| Original language | American English |
| Awarding Institution |
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| Supervisor | Jeffrey Willardson (Supervisor) |