Mike's research has two primary areas that investigate how the cardiovascular system adapts to both (i) exercise training and (ii) hypoxic exposure. The interaction between these primary areas is also of specific interest, given the importance of exercise capacity in adapting to an environmental stressor such as high altitude hypoxia.
In relation to high altitude, Mike is especially interested in the divergent pathways of adaptation taken by high altitude native populations, and the mechanisms underpinning their remarkable adaptation to one of Earth's most inhospitable environments. Recent work in Nepal (2016) and Peru (2018) has aimed to investigate the role of the cardiovascular system in the superior exercise capacity of Sherpa at high altitude. Subsequent expeditions planned for 2019 and 2020 will examine whether Ethiopian populations exhibit the same physiological adaptations as Himalayan Sherpa and Peruvian Andeans.
The second arm of Mike's work investigates the role of exercise training in shaping the cardiovascular system to promote life-long health and well-being. Of specific interest is the potential for 'windows of opportunity' during childhood that may represent a time in development that is most likely to bring about significant physiological adaptation. If periods of accelerated cardiac adaptation exist in line with surges in growth hormones (e.g. puberty), these time periods would represent a unique opportunity to shape cardiovascular heath for the remainder of life. This work aims to determine whether cardiac structure and function show greater adaptation to exercise training during pre-, circa- or post-adolescence
Refereed Academic Journal Articles
Stembridge M and Levine B (2019). Cardiac performance with chronic hypoxia: Mechanisms regulating stroke volume. Current Oponions in Physiology [In Press].
Rieger MG, Nowak-Flück D, Morris LE, Niroula S, Sherpa KT, Tallon CM, Stembridge M, Ainslie PN, McManus A (2018). UBC-Nepal Expedition: Intra-cranial hemodynamic response to exercise in Sherpa children residing at high altitude. High Alt Med Bio [In press].
Willie CK, Stembridge M, Hoiland RL, Tymko MM, Steinback C, Moore J, Anholm J, Subedi P, Niroula S, McNeil CJ, McManus A, MacLeod DB, Ainslie PN (2018). UBC-Nepal Expedition: An experimental overview of the 2016 University of British Columbia Scientific Expedition to Nepal Himalaya. PLOS One [In press].
Tremblay JC, Hoiland RL, Carter HH, Howe CA, Stembridge M, Willie CK, Gasho C, Macleod DB, Pyke KE & Ainslie PN. (2018). UBC-Nepal Expedition: Upper and Lower Limb Conduit Artery Shear Stress and Flow-Mediated Dilation on Ascent to 5050 m in Lowlanders and Sherpa. Am J Physiol Heart Circ Physiol.
Stembridge M, Ainslie PN, Boulet LM, Anholm J, Subedi P, Tymko MM, Willie CK and Shave R (2018). The independent and combined effects of hypovolemia and pulmonary vasoconstriction on left ventricular function and exercise capacity at high altitude. J Physiol (In Press).
Perkins D, Dawkins T and Stembridge M (2018). Early exercise for lifelong benefit: Sustained cardiac programming in rats and the potential translation to humans. J Physiol 10.1113/JP275993.
Lord R, MacLeod D, George K, Oxborough D, Shave R & Stembridge M (2018). Reduced left ventricular filling following blood volume extraction does not result in compensatory augmentation of cardiac mechanics. Exp Physiol.
Hansen AB, Hoiland RL, Lewis NCS, Tymko MM, Tremblay JC, Stembridge M, Nowak-Fluck D, Carter HH, Bailey DM & Ainslie PN. (2018). UBC-Nepal expedition: The use of oral antioxidants does not alter cerebrovascular function at sea-level or high-altitude. Exp Physiol.
Vermeulen TD, Boulet LM, Stembridge M, Williams AM, Anholm JD, Subedi P, Gasho C, Ainslie PN and Foster GE (2017). Influence of myocardial oxygen demand on the coronary vascular response to arterial blood gas fluctuations in humans. . Am J Physiol Heart Circ Physiol, ajpheart.
Bain AR, Ainslie PN, Hoiland RL, Barak OF, Drvis I, Stembridge M, MacLeod DM, McEneny J, Stacey BS, Tuaillon E, Marchi N, Fayd'Herbe De Maudave A, Dujic Z, MacLeod DB, and Bailey DM (2017). Competitive apnea and its effect on the human brain: focus on the redox-regulation of blood–brain barrier permeability and neuronal–parenchymal integrity. FASEB. doi: 10.1096/fj.201701031R
Rothwell O, George K, Somauroo J, Lord R, Stembridge M, Shave, Hoffman M, Wilson M, Haddad F, Ashley E, Eijsvogels T and Oxborough D (2017). Right Ventricular Structure and Function in the Veteran Ultramarathon runner: Is there Evidence for Chronic Maladaptation? J Am Soc Echocardiography.
Stembridge M, Hoiland RL, Bain AR, Barak OF, Drvis I, Macleod DB, Macleod DM, Madden D, Batinic T, O'Donoghue P, Shave R, Dujic Z and Ainslie PN. Influence of lung volume on circulatory function and arterial blood gases during prolonged breath holding in elite apnea divers. Exp Physiol, DOI: 10.1113/EP086429
Atencia R, Stohr EJ, Drane AL, Stembridge M, Howatson G, Lopez PR, Feltrer Y, Tafon B, Redrobe S, Peck B, Eng J, Unwin S, Sanchez CR and Shave RS (2017). Hemodynamic responses to four different anesthetic protocols in wold-born captive chimpanzees (Pan Troglodytes). Journal of Zoo and Wildlife Medicine, In Press.
Rieger M, Hoiland RL, Tremblay JC, Stembridge M, Bain AR, Fluck D, Subedi P, Anholm J and Ainslie P (2017). One session of remote ischemic preconditioning does not improve vascular function in acute normobaric and chronic hypobaric hypoxia. Exp Physiol July 12; doi: 10.1113/EP086441
Fluck D, Morris L, Niroula S, Tallon C, Sherpa K, Stembridge M, Ainslie PN and McManus A (2017). UBC-Nepal Expedition: Markedly lower cerebral blood flow in high altitude Sherpa children compared to children residing at sea-level. J Appl Physiol (1985), Jun 1: doi: 10.1152/japplphysiol.00292.2017.
Stohr EJ, Stembridge M, Shave R, Samuels JT, Stone K and Esformes, JI (2017). Systolic and Diastolic LV Mechanics during and following Resistance Exercise. Med Sci Sports Exercise, May 16. doi: 10.1249/MSS.0000000000001326.
Boulet LM, Lovering AT, Tymko MM, Day TA, Stembridge M, Nguyen TA, Ainslie PN & Foster GE. (2017). Reduced blood flow through intrapulmonary arteriovenous anastomoses during exercise in lowlanders during acclimatization to high altitude. Exp Physiol June 1; 102(6): 670-68.
Hoiland R, Bain AR, Tymko MM, Rieger MG, Howe CA, Willie CK, Hansen AB, Fluck D, Wildfong KW, Stembridge M, Subedi P, Anholm JD and Ainslie PN (2017). Adenosine receptor dependent signaling is not obligatory for normobaric and hypobaric hypoxia-induced cerebral vasodilation in humans. J Appl Physiol (1985), Jan 12:jap 00840.2016.
Tymko MM, Tremblay JC, Hansen A, Howe C, Willie CK, Stembridge M, Green D, Hoiland R, Subedi P, Anholm J and Ainslie P (2017). The effect of alpha1-adrenergic blockade on post-exercise brachial artery flow-mediated dilatation at sea-level and high-altitude. J Physiology. Mar 1; 595(5):1671-1686.
Stembridge M, Ainslie PN, Donnelly J, McLeod NT, Joshi S, Hughes MG, Sherpa K & Shave RE. (2016). Cardiac structure and function in adolescent Sherpa; effect of habitual altitude and developmental stage. Am J Physiol Heart Circ Physiol, ajpheart 00938 02015
Bain AR, Ainslie PN, Hoiland RL, Barak OF, Cavar M, Drvis I, Stembridge M, MacLeod DM, Bailey DM, Dujic Z & Macleod DB (2016). Cerebral oxidative metabolism is decreased with extreme apnoea in humans; impact of hypercapnia. J Physiology Sep 15;594(18):5317-28.
Boulet LM, Stembridge M, Tymko MM, Tremblay JC and Foster GE (2016). The effects of graded changes in oxygen and carbon dioxide tension on coronary blood velocity independent of myocardial energy demand. Am J Physiol Heart Circ Physiol, 311 (2) P326-36.
Black JM, Stohr E, Stone K, Pugh CJ, Stembridge M, Shave R and Esformes JI (2016). The effect of an acute bout of resistence exercise on carotid artery strain and strain rate. Physioligical Reports, Sept; 4(17).
Williams AM, Shave RE, Stembridge M and Eves ND (2016). Females have greater left ventricular twist mechanics than males during acute reductions to preload. Am J Physiol Heart Circ Physiol, 311 (1) P76-84.
Armstrong C, Samuel J, Yarlett A, Cooper SM, Stembridge M and Stohr EJ (2016). The Effects of Exercise Intensity vs. Metabolic State on the Variability and Magnitude of Left Ventricular Twist Mechanics during Exercise. PLoS One, 11 (4) e0154065.
Lord R, George K, Somauroo J, Stembridge M, Jain N, Hoffman MD, Shave R, Haddad F, Ashley E, Jones H and Oxborough D (2016). Alterations in Cardiac Mechanics Following Ultra-Endurance Exercise: Insights from Left and Right Ventricular Area-Deformation Loops. J Am Soc Echocardiography Sep;29(9):879-887.
Hoiland RL, Ainslie PN, Bain AR, Macleod DB, Stembridge M, Drvis I, Madden D, Barak OF, MacLeod DM & Dujic Z. (2016). Beta 1-blockade increases maximal apnea duration in elite breath hold divers. J Appl Physiol (1985), jap 00127 02016.
Bain AR, Dujic Z, Hoiland RL, Barak OF, Madden D, Drvis I, Stembridge M, Macleod DB, Macleod DM and Ainslie PN (2015). Peripheral chemoreflex inhibition with low-dose dopamine; new insight into mechanisms of extreme apnea. AJP Reg, Int and Com Phys.
Stembridge M, Ainslie PN and Shave R (2015). Mechanisms underlying reductions in stroke volume at rest and during exercise at high altitude. Eur J Spt Sci. Aug;16(5):577-84.
Stohr EJ, Stembridge M & Esformes JI. (2015). In vivo human cardiac shortening and lengthening velocity is region-dependent and not coupled with heart rate: 'Longitudinal' strain rate markedly underestimates apical contribution. Exp Physiol. Apr 20;100(5) 507-18
Stembridge M, Ainslie PN, Hughes MG, Stohr EJ, Cotter JD, Tymko MM, Day TA, Bakker A & Shave RE. (2015). Impaired myocardial function does not explain reduced left ventricular filling and stroke volume at rest or during exercise at high altitude. J Appl Physiol (1985), JAP 00995 02014.
Utomi V, Oxborough D, Ashley E, Lord R, Fletcher S, Stembridge M, Shave R, Hoffman MD, Whyte G, Somauroo J, Sharma S & George K. (2015). The impact of chronic endurance and resistance training upon the right ventricular phenotype in male athletes. Eur J Appl Physiol.
Stembridge M, Ainslie PN & Shave R. (2014). Short-term adaptation and chronic cardiac remodelling to high altitude in lowlander natives and Himalayan Sherpa. Exp Physiol.
Hoiland RL, Foster GE, Donnelly J, Stembridge M, Willie CK, Smith KJ, Lewis NC, Lucas SJ, Cotter JD, Yeoman DJ, Thomas KN, Day TA, Tymko MM, Burgess KR & Ainslie PN. (2014). Chemoreceptor responsiveness at sea level does not predict the pulmonary pressure response to high altitude. Chest.
Stembridge M, Ainslie PN, Hughes MG, Stohr EJ, Cotter JD, Nio AQ & Shave R. (2014). Ventricular structure, function and mechanics at high altitude: chronic remodelling in Sherpa verses short-term lowlander adaptation. J Appl Physiol (1985).
Tremblay JC, Lovering AT, Ainslie PN, Stembridge M, Burgess KR, Bakker A, Donnelly J, Lucas SJ, Lewis NC, Dominelli PB, Henderson WR, Dominelli GS, Sheel AW & Foster GE. (2014). Hypoxia, not pulmonary vascular pressure induces blood flow through intrapulmonary arteriovenous anastomoses. J Physiol.
Foster GE, Ainslie PN, Stembridge M, Day TA, Bakker A, Lucas SJ, Lewis NC, Macleod DB & Lovering AT. (2014). Resting pulmonary haemodynamics and shunting: a comparison of sea-level inhabitants to high altitude Sherpas. J Physiol.
Lewis NC, Bailey DM, Dumanoir GR, Messinger L, Lucas SJ, Cotter JD, Donnelly J, McEneny J, Young IS, Stembridge M, Burgess KR, Basnet AS & Ainslie PN. (2014). Conduit artery structure and function in lowlanders and native highlanders: relationships with oxidative stress and role of sympathoexcitation. J Physiol.
Lord R, Somauroo J, Stembridge M, Jain N, Hoffman MD, George K, Jones H, Shave R, Haddad F, Ashley E & Oxborough D. (2014). The right ventricle following ultra-endurance exercise: insights from novel echocardiography and 12-lead electrocardiography. Eur J Appl Physiol.
Stohr EJ, Meah VL & Stembridge M. (2014). Combined neonatal therapies for cardiac function in adulthood - live together, die alone? J Physiol 592, 825-826.
Stone KJ, Hughes MG, Stembridge M, Meyers RW, Newcombe DJ & Oliver JL. (2014). The influence of playing surface on physiological and performance responses during and after soccer simulation. Eur J Sport Sci, 1-8.
Utomi V, Oxborough D, Ashley E, Lord R, Fletcher S, Stembridge M, Shave R, Hoffman MD, Whyte G, Somauroo J, Sharma S & George K. (2014). Predominance of normal left ventricular geometry in the male 'athlete's heart'. Heart 100, 1264-1271.
Hughes MG, Birdsey L, Meyers R, Newcombe D, Oliver JL, Smith PM, Stembridge M, Stone K & Kerwin DG. (2013). Effects of playing surface on physiological responses and performance variables in a controlled football simulation. J Sports Sci 31, 878-886.
Stone, K.J., Oliver, J.L., Hughes, M.G., Stembridge, M.R., Newcombe, D.J. & Meyers, R.W. (2011). Development of a soccer simulation protocol to include repeated sprints and agility. International Journal of Sports Physiology and Performance.
Turner, A, Walker, S, Stembridge, M, Coneyworth, P, Reed, G, Birdsey, L, Barter, P, Moody, J (2011). Testing Battery for the Assessment of Fitness in Soccer Players. Strength & Conditioning Journal: 33 (5), 29-39.
Oliver, J and Stembridge, M (2011). Use of a heart rate:ground contact index to monitor and predict middle distance running. European Journal of Sport Science. 11 (6), 431-436.
Conference Presentations
Mike has presented as part of symposia and submitted over 45 conference abstracts to both national and international conferences. The following have been published as abstracts:
Williams A.M., Ainslie P.N., Anholm J.D., Gasho, C., Subedhi P. & Stembridge M. Left ventricular twist is influenced by both o2 saturation and ß1-adrenergic stimulation in acute and chronic hypoxia. 20th International Hypoxia Symposia.
Subedi P, Stembridge M, Williams A, Gasho C, Willie C, Ainslie PN, Anholm JD. Pulmonary Vascular Response to Hypobaric Hypoxia and Supplemental Oxygen during Gradual Ascent in the Himalayas. 20th International Hypoxia Symposia.
Hoiland RL, MacLeod DB, Flueck D, Willie CK, Tymko MM, Tremblay JC, Howe CA, Donnelly J, Stembridge M, Patrician A, Rieger MG, Hansen AB, Santoro A, Ainslie PN. Deoxyhemoglobin regulates cerebral vasodilation in hypoxia. 20th International Hypoxia Symposia.
Boulet LM, Stembridge M, Hansen A, Ainslie PN, Foster GE. Changes in human coronary perfusion following acute and prolonged high altitude exposure. 20th International Hypoxia Symposia.
Vermeulen T.D., Boulet L.M., Stembridge M., Williams A.M., Anholm J.D., Subedhi P., Gasho, C., Ainslie P.N., & Foster G.E. influence of myocardial workload on the coronary vascular response to arterial blood gas fluctuations in humans. 20th International Hypoxia Symposia.
Mathew G. Rieger, Ryan L. Hoiland, Joshua C. Tremblay, Mike Stembridge, Anthony R. Bain, Daniela Flück, Prajan Subedi, James D. Anholm, Philip N. Ainslie One session of remote ischemic preconditioning does not improve vascular function in acute and chronic hypoxia. 20th International Hypoxia Symposia.
Busch SA, Simpson L, Moore J, Sobierajski F, Riske L, Stembridge M, Ainslie PN, and CD Steinback. Sympathetic nerve activity and vascular transduction in Lowlanders and Sherpa at 5050m. 20th International Hypoxia Symposia.
Steinback CD, Davies H, Busch SA, Van Diepen S, Simpson L, Sobierajski F, Riske L, Stembridge M, Ainslie PN, Willie CK and Moore J. Chemoreflex mediated bradycardia and arrhythmia during apnea at altitude in lowlanders but not Sherpa. 20th International Hypoxia Symposia.
Tremblay JT, Boulet LM, Tymko MM, Foster GE. (2016) The effects of intermittent hypoxia on the vasculature and carotid baroreflex regulation. FASEB J. 30:759.5 Presented at international conference of the Federation of American Societies for Experimental Biology, April 2-6, 2016 in San Diego, CA, USA.
Boulet LM, Stembridge M, Tymko MM, Tremblay JC, Foster GE. (2016) The Coronary Blood Flow Velocity Response to Oxygen and Carbon Dioxide in Humans. FASEB J. 30:733.2 Presented at the international conference of the Federation of American Societies for Experimental Biology, April 2-6, 2016 in San Diego, CA, USA.
Stembridge M, Hoiland RL, Bain AR, Barak OF, Drvis I, Macleod DB, Macleod DM, Madden D, Batinic T, Shave R, Dujic Z and Ainslie PN. Influence of lung volume on circulatory function and arterial blood gases during prolonged breath holding in elite apnea divers. American College of Sport Science Annual Meeting 2016.
Stembridge M, Ainslie PN, Donnelly J, McLeod NT, Hughes MG, Sherpa K and Shave R. Left ventricular diastolic function in Sherpa adolescents residing at high and low altitude. 19th International Hypoxia Symposia.
Donnelly, J., Cotter, J.D., Walker, R.J., Burgess, K.R, Ainslie, P.N., Stembridge, M., Curtis, A.N., Lewis, N.C.S., Basnet, A.S. & Lucas, S.J.E. Acute mountain sickness is not reliably due to fluid regulatory or autonomic stress. Proceedings of the 15th International Conference on Environmental Ergonomics, Queenstown, New Zealand. P78-80. ISBN 978-0-473-22821-7.
Stembridge M, Ainslie PN, Hughes MG, Stöhr EJ, Cotter JD, Lucas SJE, Lewis NCS, Burgess KR and Shave R. The effect of hypobaric hypoxia on left ventricular mechanics. 18th International Hypoxia Symposia.
Beasley K.M., Day TA, Foster GE, Stembridge M, Willie CK, Smith KJ, Lucas SJ Ainslie PN, Lovering AT. Patent foramen ovale does not increase AMS susceptibility during ascent to or after arrival at 5050m. 18th International Hypoxia Symposia.
Day TA, Foster GE, Stembridge M, Tymko MM, Bakker A, Ainslie PN, Lovering AT. Intrapulmonary shunt during supine exercise at sea level and at 5050 m in healthy humans. 18th International Hypoxia Symposia.
Foster GE, Ainslie PN, Stembridge M, Day TA, Bakker A, Lucas SJE, Lewis NCS, Burgess KR, MacLeod D, Lovering AT. Pulmonary vascular regulation and shunting: comparison of sea-level inhabitants to Sherpas. 18th International Hypoxia Symposia.
