Intra-abdominal pressure and rowing: the effects of inspiring versus expiring during the drive.
BACKGROUND
The lumbar vertebrae of rowers are subjected to high levels of shear and compression at mid-drive, but intra-abdominal pressure (IAP) may partially neutralize these forces. IAP fluctuates with breathing. This study compared the IAP between inspiring during the drive and expiring during the drive.


METHODS



METHODS
ten volunteers performed one 5x2-minute repetition test while inspiring during the drive and one 5x2-minute repetition test while expiring during the drive on a rowing ergometer. The five work rates were: 100, 125, 150, 175 and 200 watts at 22, 24, 26, 28 and 30 strokes per minute, respectively.


METHODS
the movement of the body while rowing was analyzed using a position sensor, and IAP was measured using a pressure transducer catheter.


RESULTS
A 2x5 repeated measures analysis of variance showed that there was a significant interaction for the dependent variable mid-drive IAP (p<0.05), with the mid-drive IAP increasing at a greater rate while expiring during the drive relative to inspiring during the drive. Across work rate, the mid-drive IAP and minimal IAP were significantly higher while expiring during the drive than inspiring during the drive (p<0.05). Across breathing pattern, the minimal IAP, maximal IAP, average change in IAP and mid-drive IAP increased significantly with work rate (p<0.05).


CONCLUSIONS
The data show that expiring during the drive leads to a greater mid-drive IAP than inspiring during the drive.
Manning
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Department of Kinesiology and Physical Education, Northern Illinois University, DeKalb 60115, USA.
Plowman
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Drake
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Looney
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Ball
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D000005:Abdomen / Q000502:physiology*; D000328:Adult; D000704:Analysis of Variance; D016552:Ergometry; D005260:Female; D006801:Humans; D001239:Inhalation / Q000502:physiology; D008159:Lumbar Vertebrae / Q000502:physiology; D008297:Male; D009068:Movement / Q000502:physiology; D011187:Posture / Q000502:physiology; D011312:Pressure; D012123:Pulmonary Ventilation / Q000502:physiology; D015203:Reproducibility of Results; D012119:Respiration; D015656:Respiratory Mechanics / Q000502:physiology*; D012815:Signal Processing, Computer-Assisted; D013177:Sports / Q000502:physiology*; D013314:Stress, Mechanical; D014160:Transducers, Pressure