What question did this study set out to answer?

To determine whether contractile fatigue of the quadriceps occurs after cycling in patients with COPD and whether it limits improvements in exercise tolerance following bronchodilation.

April 28, 2003American Journal of Respiratory and Critical Care Medicine

Contractile Leg Fatigue after Cycle Exercise

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Authors

DSDidier SaeyInstitut Universitaire de Cardiologie et de Pneumologie de Québec RDRichard DebigaréHôpital Saint-François d'Assise PLPierre LeblancUniversité Claude Bernard Lyon 1

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Implication

Placebo-controlled trial reveals that quadriceps contractile fatigue limits exercise endurance gains from ipratropium in COPD, indicating muscle exhaustion offsets bronchodilation benefits.

Key Points

To determine whether contractile fatigue of the quadriceps occurs after cycling in patients with COPD and whether it limits improvements in exercise tolerance following bronchodilation.
Eighteen patients with COPD performed two constant work-rate cycle exercise tests to exhaustion following nebulization of placebo or 500 µg ipratropium bromide.
Contractile muscle fatigue was assessed and defined as a postexercise decline in quadriceps twitch force greater than 15% from baseline resting values.
Endurance time across the overall cohort rose from 322 ± 188 seconds with placebo to 440 ± 244 seconds with ipratropium (p = 0.06).
In nine patients with contractile fatigue, endurance time did not improve with ipratropium (394 ± 220 s with placebo vs. 400 ± 119 s with ipratropium) despite an 11% gain in FEV1, whereas non-fatiguing patients improved significantly (249 ± 124 s to 479 ± 298 s, p < 0.05).
Improvement in endurance time with ipratropium correlated significantly with quadriceps twitch force measured at 10 minutes post-placebo exercise (r = 0.59, p = 0.01).

Cite This Study

Saey et al. (2003) studied this question.

synapsesocial.com/papers/6a7c59fda540d02696c2dbd3 https://doi.org/10.1164/rccm.200208-856oc

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Implication

Placebo-controlled trial reveals that quadriceps contractile fatigue limits exercise endurance gains from ipratropium in COPD, indicating muscle exhaustion offsets bronchodilation benefits.

Contractile Leg Fatigue after Cycle Exercise

Discussion

Member takes

Implication

Key Points

Cite This Study

Contractile Leg Fatigue after Cycle Exercise

Discussion

Member takes

Implication

Key Points

Cite This Study

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