Nine adult female subjects ages 21.33 (± 1.225 s.d.), weight 125.56 pounds (± 2.121) were first asked to perform a maximal voluntary contraction for 15 seconds on an abdominal crunch machine. Secondly, they performed a five second yoga breath and five sit-ups on an inclined board. Their exertion was measured using Biopac hardware and electromyographic analysis. Subjects were able to exert maximal voluntary contractions on the abdominal crunch machine of 1.335 Hz (± 0.668 s.d.), 0.354 Hz (± 0.368 s.d.) during the yoga breath, and 1.165 Hz (± 0.776 s.d.) during an inclined board sit-up.
Statistical significance in the study was determined through a t-test. Furthermore, subjects were able to elicit 86.22% (±15.00 s.d.) of their maximal voluntary contraction during an inclined board sit-up, and only 26.76% 9 (± 16.79 s.d.) during the yoga breath.