Document Detail


Effects of priming exercise on the speed of adjustment of muscle oxidative metabolism at the onset of moderate-intensity step transitions in older adults.
MedLine Citation:
PMID:  22422668     Owner:  NLM     Status:  Publisher    
Abstract/OtherAbstract:
Ageing is associated with a functional decline of the oxidative metabolism due to progressive limitations of both O(2) delivery and utilization. Priming exercise (PE) increases the speed of adjustment of oxidative metabolism during successive moderate intensity transitions. We tested the hypothesis that such improvement is due to a better matching of O(2) delivery to utilization within the working muscles. In 21 healthy older adults (65.7± 5 yrs) we measured contemporarily and non-invasively indexes of the overall speed of adjustment of the oxidative metabolism (i.e. pulmonary V O(2) kinetics), of the bulk O(2) delivery (i.e. cardiac output) and of the rate of muscle deoxygenation (i.e. deoxygenated haemoglobin, HHb) during moderate intensity step transitions, either with (ModB) or without (ModA) prior PE. The local matching of O2 delivery to utilization was evaluated by the ΔHHb/Δ V O(2) ratio index. The overall speed of adjustment of the V O(2) kinetics was significantly increased in ModB compared to ModA (p<0.05). On the contrary, the kinetics of cardiac output was unaffected by PE. At the muscle level, ModB was associated with a significant reduction of the "overshoot" in the ΔHHb/Δ VO(2) ratio compared to ModA (p<0.05), suggesting an improved O(2) delivery. Our data are compatible with the hypothesis that, in older adults, PE, prior to moderate intensity exercise, beneficially affects the speed of adjustment of oxidative metabolism due to an acute improvement of the local matching of O(2) delivery to utilization.
Authors:
Gabriela De Roia; Silvia Pogliaghi; Alessandra Adami; Cristina Papadopoulou; Carlo Capelli
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Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2012-3-14
Journal Detail:
Title:  American journal of physiology. Regulatory, integrative and comparative physiology     Volume:  -     ISSN:  1522-1490     ISO Abbreviation:  -     Publication Date:  2012 Mar 
Date Detail:
Created Date:  2012-3-16     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100901230     Medline TA:  Am J Physiol Regul Integr Comp Physiol     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Affiliation:
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