Modulation of ventilatory mechanics during exercise in ventilation-limited populations

Butcher, Scott J.
June 2008
Applied Physiology, Nutrition & Metabolism;Jun2008, Vol. 33 Issue 3, p536
Academic Journal
The aim of this thesis was to examine the impact of modifications to ventilatory constraint in populations who have reductions in expiratory flow and ventilatory limitations during exercise. The first study examined the effect of the self-contained breathing apparatus (SCBA) regulator on work of breathing (WOB) and lung volume changes in healthy subjects. The second study further examined the effect of the SCBA on the above outcomes, as well as on pulmonary function and respiratory muscle fatigue during stair-stepping (in healthy subjects). In addition, the effect of breathing heliox on the aforementioned variables was studied. The third thesis study examined the effect of heliox on ventilatory constraint, exercise tolerance, and leg muscle fatigue in patients with chronic obstructive pulmonary disease (COPD). The main results of the first study were that, compared with a low-resistance breathing valve (RV), the SCBA regulator increased inspiratory elastic (32%), expiratory resistive (59%), and total WOB (13%), and increased end-expiratory lung volume creating a plateau in end-inspiratory lung volume at approximately 90% of vital capacity. When these variables were examined with the full SCBA and compared with the RV in the second study, similar results were found. In addition, resting pulmonary function was reduced with the SCBA. Exercise with the SCBA induced reductions in both inspiratory and expiratory maximal pressures indicating the presence of respiratory muscle fatigue. When compressed air was replaced with heliox in the SCBA, end-expiratory lung volume, total WOB, and respiratory muscle fatigue were reduced. These observations regarding the effect of heliox on ventilatory function led to the third study, which found that heliox increased exercise tolerance (53%) and leg muscle fatigue (15%) in patients with COPD, but only in those limited by ventilatory constraints and who did not have a significant level of leg fatigue while breathing room air. Those patients who did have leg fatigue on room air did not increase exercise tolerance despite reduced ventilatory constraint. Together, these findings indicate that reducing ventilatory constraint during exercise can have specific positive effects on exercise performance in populations who are ventilatory limited and have implications for occupational or rehabilitation exercise training.


Related Articles

  • The Effects of Respiratory Muscle Training in Highly-Trained Rowers. Driller, Matthew; Paton, Carl // Journal of Exercise Physiology Online;Dec2012, Vol. 15 Issue 6, p93 

    Respiratory muscle training has been proposed as a beneficial means of improving respiratory muscle function and performance in athletes. Therefore, the aim of this study was to determine the effects of a 6-wk specific respiratory muscle training program on the performance and respiratory muscle...

  • ESTIMATING RESPIRATORY MECHANICS WITH CONSTANT-PHASE MODELS IN HEALHTY LUNGS FROM FORCED OSCILLATIONS MEASUREMENTS. Ionescu, Clara; Desager, Kristine; de Keyser, Robin // Studia Universitatis Vasile Goldis Seria Stiintele Vietii (Life ;2009, Vol. 19 Issue 1, p123 

    Demanding minimal cooperation from the patient, the forced oscillation technique (FOT) is an attractive non-invasive lung function test. Its successful application to assess respiratory mechanics makes it an interesting topic for further investigations. Recent trends in signal processing and...

  • Spirometry and Respiratory Muscle Function During Ascent to Higher Altitudes. Sharma, Sat; Brown, Bryce // Lung;Mar2007, Vol. 185 Issue 2, p113 

    Alteration in lung function at high altitude influences exercise capacity, worsens hypoxia, and may predispose to high-altitude illness. The effect of high altitude on lung function and mechanisms responsible for these alterations remain unclear. Seven adult male mountaineers were followed...

  • The Study of Exercise Aerobically in Pulmonary Function Children Ahwaz City. Ghanbarzadeh, Mohsen; Habibi, Abdolhamid; Ghanbarzadeh, Peiman; Ebadi, Sina // International Table Tennis Federation Sports Science Congress Co;Sep2010, Issue 6, p9 

    We studied mechanical ventilatory constraints in 13 aerobically trained (Tr) and 11 untrained (UT) prepubescent children by plotting the exercise flow-volume (F-V) loops within the maximal F-V loop (MFVL) measured at rest. The MFVL allowed determining forced vital capacity (FVC) and maximal...

  • Impact of Low Filter Resistances on Subjective and Physiological Responses to Filtering Facepiece Respirators. Roberge, Raymond J.; Kim, Jung-Hyun; Powell, Jeffrey B.; Shaffer, Ronald E.; Ylitalo, Caroline M.; Sebastian, John M. // PLoS ONE;Dec2013, Vol. 8 Issue 12, p1 

    Ten subjects underwent treadmill exercise at 5.6 km/h over one hour while wearing each of three identical appearing, cup-shaped, prototype filtering facepiece respirators that differed only in their filter resistances (3 mm, 6 mm, and 9 mm H2O pressure drop). There were no statistically...

  • The Effects of Respiratory-Muscle Training on Exercise in Older Women. Watsford, Mark; Murphy, Aron // Journal of Aging & Physical Activity;Jul2008, Vol. 16 Issue 3, p245 

    This research examined the effects of respiratory-muscle (RM) training on RM function and exercise performance in older women. Twenty-six women (60-69 yr of age) were assessed for spirometry, RM strength (maximal inspiratory and expiratory pressure), inspiratory-muscle endurance, and walking...

  • Expiratory flow limitation and breathing strategies in overweight adolescents during submaximal exercise. Gibson, N; Johnston, K; Bear, N; Stick, S; Logie, K; Hall, G L // International Journal of Obesity;Jan2014, Vol. 38 Issue 1, p22 

    Objective:To investigate whether ventilatory factors limit exercise in overweight and obese children during a 6-min step test and to compare ventilatory responses during this test with those of healthy weight children.Design:Cross-sectional, prospective comparative study.Subjects:Twenty-six...

  • Función pulmonar y obesidad. Carpió, Carlos; Santiago, Ana; García de Lorenzo, Abelardo; Álvarez-Sala, Rodolfo // Nutricion Hospitalaria;nov2014, Vol. 30 Issue 5, p1054 

    Excess bodyweight has an important impact on the physiology of breathing. In fact, it affects resting lung volumes and exercise capacity. These effects appear as a consequence of ventilatory and inflammatory changes commonly associated to obesity. As a result, obese individuals have a rapid and...

  • Isocapnic hyperpnea with a portable device in Cystic Fibrosis: an agreement study between two different set-up modalities. Gambazza, Simone; Ceruti, Clara; Brivio, Anna; Piaggi, Giancarlo; Karapanagiotis, Solon; Colombo, Carla // Journal of Clinical Monitoring & Computing;Oct2015, Vol. 29 Issue 5, p569 

    To evaluate the bias and precision of the respiratory muscle training device formulas to predict respiratory minute volume (RMV) and volume of the reservoir bag (BV) on a cohort of subjects with Cystic Fibrosis (CF). CF patients with available pulmonary function tests and maximal voluntary...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics