Document Detail


Inspiratory muscle training enhances pulmonary O(2) uptake kinetics and high-intensity exercise tolerance in humans.
MedLine Citation:
PMID:  20507969     Owner:  NLM     Status:  In-Process    
Abstract/OtherAbstract:
Fatigue of the respiratory muscles during intense exercise might compromise leg blood flow, thereby constraining oxygen uptake (Vo(2)) and limiting exercise tolerance. We tested the hypothesis that inspiratory muscle training (IMT) would reduce inspiratory muscle fatigue, speed Vo(2) kinetics and enhance exercise tolerance. Sixteen recreationally active subjects (mean + or - SD, age 22 + or - 4 yr) were randomly assigned to receive 4 wk of either pressure threshold IMT [30 breaths twice daily at approximately 50% of maximum inspiratory pressure (MIP)] or sham treatment (60 breaths once daily at approximately 15% of MIP). The subjects completed moderate-, severe- and maximal-intensity "step" exercise transitions on a cycle ergometer before (Pre) and after (Post) the 4-wk intervention period for determination of Vo(2) kinetics and exercise tolerance. There were no significant changes in the physiological variables of interest after Sham. After IMT, baseline MIP was significantly increased (Pre vs. Post: 155 + or - 22 vs. 181 + or - 21 cmH(2)O; P < 0.001), and the degree of inspiratory muscle fatigue was reduced after severe- and maximal-intensity exercise. During severe exercise, the Vo(2) slow component was reduced (Pre vs. Post: 0.60 + or - 0.20 vs. 0.53 + or - 0.24 l/min; P < 0.05) and exercise tolerance was enhanced (Pre vs. Post: 765 + or - 249 vs. 1,061 + or - 304 s; P < 0.01). Similarly, during maximal exercise, the Vo(2) slow component was reduced (Pre vs. Post: 0.28 + or - 0.14 vs. 0.18 + or - 0.07 l/min; P < 0.05) and exercise tolerance was enhanced (Pre vs. Post: 177 + or - 24 vs. 208 + or - 37 s; P < 0.01). Four weeks of IMT, which reduced inspiratory muscle fatigue, resulted in a reduced Vo(2) slow-component amplitude and an improved exercise tolerance during severe- and maximal-intensity exercise. The results indicate that the enhanced exercise tolerance observed after IMT might be related, at least in part, to improved Vo(2) dynamics, presumably as a consequence of increased blood flow to the exercising limbs.
Authors:
Stephen J Bailey; Lee M Romer; James Kelly; Daryl P Wilkerson; Fred J DiMenna; Andrew M Jones
Related Documents :
15235319 - Influence of dca on pulmonary (.-)v(o2) kinetics during moderate-intensity cycle exercise.
3101259 - An effect of co2 on the maximum safe direct decompression to 1 bar from oxygen-nitrogen...
10487379 - Maximal accumulated oxygen deficit must be calculated using 10-min time periods.
3816789 - Urea synthesis from ammonia in periportal and pericentral regions of the liver lobule. ...
3558239 - Physiological factors affecting o2 transport by hemoglobin in an in vitro capillary sys...
20654739 - Influence of body position on muscle deoxy[hb+mb] during ramp cycle exercise.
1839669 - Isokinetic trunk-strength deficits in people with and without low-back pain: a comparat...
19052809 - Outcome assessment of breast distortion following submuscular breast augmentation.
16863899 - Comparison of two pain-management strategies during chest tube removal: relaxation exer...
Publication Detail:
Type:  Journal Article; Randomized Controlled Trial     Date:  2010-05-27
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  109     ISSN:  1522-1601     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  2010 Aug 
Date Detail:
Created Date:  2010-08-10     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  457-68     Citation Subset:  IM    
Affiliation:
School of Sport and Health Sciences, St. Luke's Campus, Univ. of Exeter, Heavitree Road, Exeter, Devon EX1 2LU, UK.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  The effect of increased genioglossus activity and end-expiratory lung volume on pharyngeal collapse.
Next Document:  The ins and outs of deep breathing: mechanisms of respiratory motor plasticity.