Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and the University of Texas Southwestern Medical Center, Dallas, TX.
Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and the University of Texas Southwestern Medical Center, Dallas, TX.
Chest. 2011 Aug;140(2):454-460. doi: 10.1378/chest.10-1088. Epub 2011 Jan 27.
Obesity alters breathing mechanics during exercise. Weight loss improves lung function at rest, but the effect of weight loss, especially regional fat loss, on exercise breathing mechanics is unclear. We hypothesized that weight loss, especially a decrease in abdominal fat, would improve breathing mechanics during exercise because of an increase in end-expiratory lung volume (EELV).
Nine obese men were studied before and after weight loss (13% ± 8% of total fat weight, mean ± SD). Subjects underwent pulmonary function testing, underwater weighing, fat distribution estimates (MRI), and graded cycle ergometry before and after a 12-week diet and exercise program. In seven men, esophageal and gastric pressures were measured. The effects of weight loss were analyzed at rest, at ventilatory threshold (VTh), and during peak exercise by dependent Student t test, and the relationship among variables was determined by correlation analysis.
Subjects lost 7.4 ± 4.2 kg of body weight (P < .001), but the distribution of fat remained unchanged. After weight loss, lung volume subdivisions at rest were increased (P < .05) and were moderately associated (P < .05) with changes in chest, waist, and hip circumferences. At VTh, EELV increased, and gastric pressure decreased significantly (P < .05). The changes in waist circumference, hip circumference, BMI, and sum of chest, waist, and hip circumferences were also consistently and significantly correlated (P < .05) with changes in gastric pressure during exercise at VTh.
Modest weight loss improves breathing mechanics during submaximal exercise in otherwise healthy obese men, which is clinically encouraging. Improvement appears to be related to the cumulative loss of chest wall fat.
肥胖会改变运动时的呼吸力学。减肥可以改善休息时的肺功能，但减肥的效果，尤其是局部脂肪减少对运动呼吸力学的影响尚不清楚。我们假设，由于呼气末肺容积（EELV）增加，减肥，尤其是腹部脂肪减少，会改善运动时的呼吸力学。
研究了 9 名肥胖男性在减肥前后（全身脂肪重量的 13%±8%，平均值±标准差）的情况。受试者在 12 周饮食和运动计划前后接受了肺功能测试、水下称重、脂肪分布估计（MRI）和分级踏车运动试验。在 7 名男性中，测量了食管和胃内压力。通过独立样本 t 检验分析减肥的效果，在休息时、通气阈（VTh）时和峰值运动时进行分析，并通过相关分析确定变量之间的关系。
受试者体重减轻了 7.4±4.2kg（P<.001），但脂肪分布保持不变。减肥后，休息时肺容积各部分增加（P<.05），与胸部、腰部和臀部周长的变化中度相关（P<.05）。在 VTh 时，EELV 增加，胃内压显著降低（P<.05）。腰围、臀围、BMI 以及胸、腰、臀围总和的变化在 VTh 时与胃内压的变化也呈一致且显著的相关性（P<.05）。
在健康肥胖男性中，适度的减肥可以改善亚最大运动时的呼吸力学，这在临床上是令人鼓舞的。改善似乎与胸壁脂肪的累积损失有关。
