Respiratory energetics during exercise at high altitude

被引:38
作者
Cibella, F
Cuttitta, G
Romano, S
Grassi, B
Bonsignore, G
Milic-Emili, J
机构
[1] CNR, Ist Fisiopatol Resp, I-90146 Palermo, Italy
[2] CNR, Ist Tecnol Biomed Avanzate, I-20100 Milan, Italy
[3] McGill Univ, Meakins Christie Labs, Montreal, PQ H2X 2P2, Canada
关键词
chronic hypoxia; respiratory muscles; muscle efficiency; work of breathing;
D O I
10.1152/jappl.1999.86.6.1785
中图分类号
Q4 [生理学];
学科分类号
071003 ;
摘要
The purpose of this study was to assess the effect of high altitude (HA) on work of breathing and external work capacity. On the basis of simultaneous records of esophageal pressure and lung volume, the mechanical power of breathing ((W) over dot rs) was measured in four normal subjects during exercise at sea level (SL) and after a 1-mo sojourn at 5,050 m. Maximal exercise ventilation ((V) over dot E-max) and maximal Wrs were higher at HA than at SL (mean 185 vs. 101 1/min and 129 vs. 40 cal/min, respectively), whereas maximal O-2 uptake averaged 2.07 and 3.03 1/min, respectively. In three subjects, the relationship of Wrs to minute ventilation ((V) over dot E) was the same at SL and HA, whereas, in one individual, (W) over dot rs for any given (V) over dot E was consistently lower at HA. Assuming a mechanical efficiency (E) of 5%, the O-2 cost of breathing at HA and SL should amount to 26 and 5.5% of maximal O-2 uptake, whereas for E of 20% the corresponding values were 6.5 and 1.4%, respectively. Thus, at HA, (W) over dot rs may substantially limit external work unless E is high. Although at SL (V) over dot E-max did not exceed the critical (V) over dot E, at which any increase in (V) over dot E is not useful in terms of body energetics even for E of 5%, at HA (V) over dot E-max exceeded critical (V) over dot E even for E of 20%.
引用
收藏
页码:1785 / 1792
页数:8
相关论文
共 39 条
[1]   OXYGEN COST OF EXERCISE HYPERPNEA - MEASUREMENT [J].
AARON, EA ;
JOHNSON, BD ;
SEOW, CK ;
DEMPSEY, JA .
JOURNAL OF APPLIED PHYSIOLOGY, 1992, 72 (05) :1810-1817
[2]   OXYGEN COST OF EXERCISE HYPERPNEA - IMPLICATIONS FOR PERFORMANCE [J].
AARON, EA ;
SEOW, KC ;
JOHNSON, BD ;
DEMPSEY, JA .
JOURNAL OF APPLIED PHYSIOLOGY, 1992, 72 (05) :1818-1825
[3]   THE EFFECTS OF FORCE AND SPEED CHANGES ON THE RATE OF OXYGEN CONSUMPTION DURING NEGATIVE WORK [J].
ABBOTT, BC ;
BIGLAND, B .
JOURNAL OF PHYSIOLOGY-LONDON, 1953, 120 (03) :319-325
[4]   FORCES DEFORMING RIB CAGE [J].
AGOSTONI, E ;
MOGNONI, P ;
TORRI, G ;
MISEROCCHI, G .
RESPIRATION PHYSIOLOGY, 1966, 2 (01) :105-+
[5]  
BAYDUR A, 1982, AM REV RESPIR DIS, V126, P788
[6]  
CARPENTER TM, 1948, CARNEGIE I WASHING C, V303
[7]   Respiratory mechanics during exhaustive submaximal exercise at high altitude in healthy humans [J].
Cibella, F ;
Cuttitta, G ;
Kayser, B ;
Narici, M ;
Romano, S ;
Saibene, F .
JOURNAL OF PHYSIOLOGY-LONDON, 1996, 494 (03) :881-890
[8]   VENTILATORY WORK AND OXYGEN-CONSUMPTION DURING EXERCISE AND HYPERVENTILATION [J].
COAST, JR ;
RASMUSSEN, SA ;
KRAUSE, KM ;
OKROY, JA ;
LOY, RA ;
RHODES, J .
JOURNAL OF APPLIED PHYSIOLOGY, 1993, 74 (02) :793-798
[9]   MECHANICS OF BREATHING IN HIGH-ALTITUDE AND SEA-LEVEL SUBJECTS [J].
CRUZ, JC .
RESPIRATION PHYSIOLOGY, 1973, 17 (02) :146-161
[10]   CHEST-WALL INTERRUPTER RESISTANCE IN ANESTHETIZED PARALYZED HUMANS [J].
DANGELO, E ;
PRANDI, E ;
TAVOLA, M ;
CALDERINI, E ;
MILICEMILI, J .
JOURNAL OF APPLIED PHYSIOLOGY, 1994, 77 (02) :883-887