Casaburi R, Wasserman K, Patessio A, Ioli F, Zanaboni S, Donner C F
Division of Respiratory and Critical Care, Physiology and Medicine, Harbor-UCLA Medical Center, Torrance 90509.
Eur Respir J Suppl. 1989 Jul;7:618s-623s.
Exercise training is a mainstay of many pulmonary rehabilitation programmes. However, the physiologic basis for improved exercise tolerance is unclear. We hypothesized that since endurance training is known to reduce blood lactate at levels of work above the anaerobic threshold (AT), minute ventilation (VE) would also be lower. This might be an important benefit for the ventilatory-limited patient. We studied 10 normal subjects who performed 15 min of exercise at each of 4 work rates before and after 8 weeks of training. The lowest work rate was chosen to be below the AT; training produced a minimal decrease in VE (2.5 l.min-1). For the highest work rate, training produced a 4 mEq.l-1 decrease in lactate and a 37 l.min-1 decrease in VE. End-exercise VE reduction was well correlated with lactate reduction (r = 0.69). Seven men with chronic obstructive pulmonary disease (COPD) have also been studied. Each performed an incremental exercise test and two constant work rate tests (one above and one below AT) before and after an 8 week training period. Though responses were more variable than in normal subjects, training produced a reduced ventilatory requirement for exercise when blood lactate was reduced.
运动训练是许多肺康复计划的主要内容。然而，运动耐力提高的生理基础尚不清楚。我们推测，由于耐力训练已知能在高于无氧阈（AT）的工作强度下降低血乳酸水平，每分通气量（VE）也会降低。这对通气受限的患者可能是一个重要益处。我们研究了10名正常受试者，他们在训练8周前后，以4种工作强度分别进行15分钟的运动。最低工作强度被设定在无氧阈以下；训练使每分通气量仅有极小幅度的下降（2.5升·分钟-1）。对于最高工作强度，训练使血乳酸下降4毫当量·升-1，每分通气量下降37升·分钟-1。运动结束时每分通气量的下降与血乳酸的下降密切相关（r = 0.69）。我们还研究了7名慢性阻塞性肺疾病（COPD）男性患者。在8周训练期前后，他们每人都进行了递增运动试验和两次恒定工作强度试验（一次高于无氧阈，一次低于无氧阈）。尽管他们的反应比正常受试者更具变异性，但当血乳酸降低时，训练使运动时的通气需求减少。
