Ventilatory Responses at Peak Exercise in Endurance-Trained Obese Adults
Ventilatory Responses at Peak Exercise in Endurance-Trained Obese Adults
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DOI：
10.1378/chest.12-3022
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发表时间：
2013-10-01
期刊：
影响因子：
9.6
通讯作者：
Babb, Tony G.
中科院分区：
文献类型：
--
作者：
Lorenzo, Santiago;Babb, Tony G.
背景资料：呼吸力学的改变使健康的肥胖个体倾向于低肺容量呼吸，这使他们处于发展呼气流量限制（EFL）的风险中。在接受过减肥训练的肥胖成年人中，高的减肥需求进一步增加了他们发展EFL的风险，并增加了他们的呼吸功。本研究的目的是通过测量运动过程中的呼吸力学和呼吸动力学来调查健康肥胖（FO）成年人EFL的患病率和程度。十（七名妇女和三名男子）（平均值+/- SD，38 +/- 5岁，38% +/- 5%体脂）和10（7名女性和3名男性）控制肥胖（CO）（38 +/- 5岁，39% +/- 5%体脂）受试者进行了静水压称重、肺功能测试、循环运动测试，并测定正常人自主呼吸时的呼吸氧耗。功能残气量无差异（43% +/- 6% vs 40% +/- 9%总肺容量[TLC]），残气量（21% +/- 4% vs 21% +/- 4% TLC）或FVC（111% +/- 13% vs 104% +/- 15%预测值）。FO受试者的FEV 1较高（111% ± 13% vs 99% ± 11%预测值），TLC（106% +/- 14% vs 94% +/- 7%预测值），呼气峰流速（123% +/- 14% vs 106% +/- 13%预测值）和最大自主通气量（128% +/- 15% vs 106% +/- 13%预测值）。FO受试者的峰值摄氧量（129% +/- 16% vs 86% +/- 15%预测值）、每分钟通气量（128 +/- 35 L/min vs 92 +/- 25 L/min）和工作率（229 +/- 54 W vs 166 +/- 55 W）较高。FO受试者的平均吸气（4.65 +/- 1.09 L/s vs 3.06 +/- 1.21 L/s）和呼气（4.15 +/- 0.95 L/s vs 2.98 +/-0.76 L/s）流量更大，这导致FO受试者在运动峰值时的呼吸频率更高（51 +/- 8次呼吸/min vs 41 +/- 10次呼吸/min）。FO受试者中的机械呼吸限制相似，CO受试者，尽管更大的呼吸需求在FO subjects.Conclusion：FO个体实现高通气增加呼吸频率，匹配与高健身相关的代谢需求升高。他们这样做没有发展有意义的解释性约束。因此，具有较高肺功能的运动训练肥胖个体在高峰运动期间不受呼吸力学的限制，这可能允许健康的肥胖成年人参加剧烈运动训练。
Background: Alterations in respiratory mechanics predispose healthy obese individuals to low lung volume breathing, which places them at risk of developing expiratory flow limitation (EFL). The high ventilatory demand in endurance-trained obese adults further increases their risk of developing EFL and increases their work of breathing. The objective of this study was to investigate the prevalence and magnitude of EFL in fit obese (FO) adults via measurements of breathing mechanics and ventilatory dynamics during exercise.Methods: Ten (seven women and three men) FO (mean +/- SD, 38 +/- 5 years, 38% +/- 5% body fat) and 10 (seven women and three men) control obese (CO) (38 +/- 5 years, 39% +/- 5% body fat) subjects underwent hydrostatic weighing, pulmonary function testing, cycle exercise testing, and the determination of the oxygen cost of breathing during eucapnic voluntary hyperpnea.Results: There were no differences in functional residual capacity (43% +/- 6% vs 40% +/- 9% total lung capacity [TLC]), residual volume (21% +/- 4% vs 21% +/- 4% TLC), or FVC (111% +/- 13% vs 104% +/- 15% predicted) between FO and CO subjects, respectively. FO subjects had higher FEV1 (111% +/- 13% vs 99% +/- 11% predicted), TLC (106% +/- 14% vs 94% +/- 7% predicted), peak expiratory flow (123% +/- 14% vs 106% +/- 13% predicted), and maximal voluntary ventilation (128% +/- 15% vs 106% +/- 13% predicted) than did CO subjects. Peak oxygen uptake (129% +/- 16% vs 86% +/- 15% predicted), minute ventilation (128 +/- 35 L/min vs 92 +/- 25 L/min), and work rate (229 +/- 54 W vs 166 +/- 55 W) were higher in FO subjects. Mean inspiratory (4.65 +/- 1.09 L/s vs 3.06 +/- 1.21 L/s) and expiratory (4.15 +/- 0.95 L/s vs 2.98 +/- 0.76L/s) flows were greater in FO subjects, which yielded a greater breathing frequency (51 +/- 8 breaths/min vs 41 +/- 10 breaths/min) at peak exercise in FO subjects. Mechanical ventilatory constraints in FO subjects were similar to those in CO subjects despite the greater ventilatory demand in FO subjects.Conclusion: FO individuals achieve high ventilations by increasing breathing frequency, matching the elevated metabolic demand associated with high fitness. They do this without developing meaningful ventilatory constraints. Therefore, endurance-trained obese individuals with higher lung function are not limited by breathing mechanics during peak exercise, which may allow healthy obese adults to participate in vigorous exercise training.