The effects of inspiratory muscle training on breathing mechanics during fixed load cycling exercise

Mills, Dean and Sharpe, Graham and Johnson, Michael and Barnett, Yvonne (2011) The effects of inspiratory muscle training on breathing mechanics during fixed load cycling exercise. In: 21st European Respiratory Society Annual Congress, 24-28 Sept 2011, Amsterdam, Netherlands.

Abstract

Previous research has found that inspiratory muscle training (IMT) can improve exercise performance and tolerance (McConnell and Romer 2004). Whether these
improvements are related to changes in breathing mechanics during exercise is unknown. To investigate this, we tested the hypothesis that IMT would reduce inspiratory muscle strength during cycling exercise. Three physically active males cycled for 60 min at a fixed power output before and after 6 weeks of pressurethreshold IMT. Cycling power corresponded to maximum lactate steady state,
estimated using a lactate minimum test (Tegtbur et al. 1993). Transdiaphragmatic pressure (Pdi) was calculated as the difference between gastric and oesophageal
pressures (Pe) measured using balloon pressure catheters. Transdiaphragmatic (PTPdi) and oesophageal (PTPe) pressure-time products were calculated as the product of breathing frequency (f R) and the Pdi and Pe inspiratory time integrals respectively. Pdi, Pe and respiratory variables were measured on a breath-by-breath basis. Following IMT, peak Pdi decreased by (mean ± SD) 6.65±4.82 cmH2O
and PTPdi and PTPe by 115±31 and 102±28 cmH2O s min-1 , respectively. There was no change in the contribution of the diaphragm to total inspiratory force output
(PTPdi/PTPe). Minute ventilation and f R were also reduced by 8.73±10.20 l min-1 and 4.06±2.70 breaths min-1, respectively. In conclusion, inspiratory muscle
strength is reduced during a 60 min fixed load cycling test following IMT. These findings suggest that one of the potential mechanisms by which IMT increases
exercise tolerance may be by reducing the pressures required to sustain ventilation during fixed load cycling exercise.


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Item Type: Conference or Workshop Item (Commonwealth Reporting Category E) (Poster)
Refereed: Yes
Item Status: Live Archive
Additional Information: Poster presentation. Abstract only published.
Faculty / Department / School: Historic - Faculty of Sciences - Department of Nursing
Date Deposited: 23 Mar 2017 00:08
Last Modified: 07 Jul 2017 02:33
Fields of Research : 11 Medical and Health Sciences > 1106 Human Movement and Sports Science > 110602 Exercise Physiology
URI: http://eprints.usq.edu.au/id/eprint/30969

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