Publications, and Current Research

-Energetics of exercise at high intensity

Keenan MacDougall is studying the energy cost of high intensity cycling on a cycle ergometer. The challenge with this measurement is that oxygen uptake does not account for all of the energy cost so estimates of the anaerobic contribution must be included.

Tara Falconer McNeil is studying the energy cost of swimming in elite swimmers and evaluating the impact of ultra-short race pace training compared to the traditional high volume training.

•Energetics of running

You can see from the list of publications that Jared Fletcher and I have completed several studies evaluating the energy cost of running at intensities where measurement of oxygen uptake reveals all of the energy used for running.  We are now attempting to quantify the energy cost of running at intensities where anaerobic metabolism has a substantial contribution to the energy cost of running.  This intensity is between anaerobic threshold and maximal oxygen uptake.

•Skeletal muscle fatigue and potentiation

I have a long-standing interest in skeletal muscle fatigue. It was the topic of my doctoral dissertation and continues to be fascinating. With Arthur Cheng and Lisa Gleck, we recently published two articles on single fibre muscle fatigue with calcium measurements at 32 degrees. One paper looked at fatigue with submaximal stimulation and the other considered mechanisms of potentiation.  The next step will be to consider evaluating at more physiological temperatures.

•Voluntary activation ratio using transcranial magnetic stimulation

Estimation of the ability to maximally activate a muscle group is a difficult task. We are hoping to simplify this task, just a little by proposing a slightly different approach. We are using data already collected to do this.

To obtain a full list of my publications please use this link:  Publications

My CV is here

Below is a list of recent publications with links to the paper.

Weir, J.M., J.M. Murias, D.A. Kier and B.R. MacIntosh. What is moderate to vigorous exercise intensity? In Press, Frontiers in Physiology, 22 Sept 2021   https://doi.org/10.3389/fphys.2021.682233 (fulltext)

Power, G.A., S. Crooks, J.R. Fletcher, B.R. Macintosh, and W. Herzog. Age-related reductions in the number of serial sarcomeres contribute to shorter fascicle lengths but not elevated passive tension. Accepted for publication in J Exp Biol April 12, 2021. (fulltext)

Zimmerman, H.B., F.E. Costa, R. Sakugawa, B.R. MacIntosh, F. Diefenthaler and J.Dal Pupo. Plyometric exercise enhances twitch contractile properties but fails to improve voluntary rate of torque development in highly trained sprint athletes. In press: European Journal of Sport Science, May 16, 2021  doi: 10.1080/17461391.2021.1916083. (fulltext)

Zimmerman, H.B., D. Knihs, F. Diefenthaler, B.R. MacIntosh and J. Dal Pupo. Continuous countermovement jumps enhances twitch peak torque of quadriceps muscles and sprint performance in highly-trained sprint athletes. International Journal of Sports Physiology and Performance, 16 (4): 565-572, 2021. DOI: 10.1123/ijspp.2020-0240. (fulltext)

MacDougal, K.B., Anders M Kristensen and B.R. MacIntosh. Additional in-series compliance does not affect the length dependence of activation. J Eptl Physiol.  105(11):1907-1917, 2020. (fulltext)

Gallinger, T., J.R. Fletcher, B.R. MacIntosh.  Mechanisms of reduced plantarflexor function in cerebral palsy; smaller triceps surae moment arm and reduced force.  Journal of Biomechanics, 110:  2020. https://doi.org/10.1016/j.jbiomech.2020.109959 (fulltext)

MacDougal, K.B., A.K. Kristensen, A.N. Devrome and B.R. MacIntosh. Force-frequency relationship during fatiguing contractions of rat medial gastrocnemius muscle.  Scientific Reports, 10(1): 11575 -,2020. https://doi.org/10.1038/s41598-020-68392-6 (fulltext)

Kristensen, A.M., K.B. MacDougal, B.R. MacIntosh and K. Overgaard.  Is curvature of the force-velocity relationship in ex vivo and in situ rat soleus and medial gastrocnemius muscles affected by oxygen availability? published May, Pflugers Archiv. 472: 597-608, 2020. (fulltext)

Froyd, C., F.G. Beltrami, G.Y. Millet, B.R. MacIntosh and T.D. Noakes. More short-time recovery of peripheral fatigue after short compared with long duration time trial.  Frontiers in Physiology, 11: 399. 2020. doi: 10.3389/fphys.2020.00399 (fulltext)

Glass, L.D., A.J. Cheng and B.R. MacIntosh. Calcium sensitivity during staircase with sequential incompletely fused contractions. In Press,  in Journal of Muscle Research and CellMotility Jan, 8, 2020   (fulltext)

Zimmermann, H.B., B.R. MacIntosh and J. Dal Pupo. Does postactivation potentiation (PAP) increase voluntary performance? In Press, APNM, Sept 26, 2019. (full text)

Kruger, R.L., SJ Aboodarda, LM James, P Samozino, BR MacIntosh and GY Millet. Fatigue and recovery measured with dynamic properties vs isometric force: effects of exercise intensity.  Experimental Biology, 222: 1-10, 2019. (full text)

Holash, R.J and B.R. MacIntosh. A stochastic simulation of skeletal muscle calcium transient in a structurally realistic sarcomere model using MCell ^TM.  PlosOne, Computational Biology, 1-25, Mar 7, 2019. (full text)

Fletcher, J.R., M.J. Asmussen, S. Nigg, B.R. MacIntosh and B.M. Nigg. Effect of shoe torsional stiffness on energetics and kinetics of cycling.  Journal of Sports Sciences 37(13): 1457-1463, July, 2019.  DOI: 10.1080/02640414.2019.1565650  (full text)

Fletcher, J.R. and B.R. MacIntosh.  Changes in Achilles tendon stiffness and energy cost following a prolonged run in trained distance runners. PLOSone, published Aug 8, 2018 13(8): (17 pages) e0202026.  (full text)

Devrome, A.N. and B.R. MacIntosh.  The force-velocity relationship during isometric and isotonic fatiguing contractions.  Journal of Applied Physiology, 125:706-714, Sept 2018.  (full text)  

Glass, L.D., A.J. Cheng, and B.R. MacIntosh. Role of Ca²⁺ in changing active force during intermittent submaximal stimulation in intact, single mouse muscle fibers.  Pflügers Archiv, 470:1243-1254, 2018   (full text)Fletcher, J.R. and B.R. MacIntosh. Theoretical considerations for muscle-energy savings during distance running.  Journal of Biomechanics, 73: 73-79, May, 2018.  (full text)

Fletcher, J.R. and B.R. MacIntosh. Estimates of Achilles tendon moment arm length at different ankle joint angles: effect of passive moment.  Journal of Applied Biomechanics, June 24, 34(3): 220-225, 2018.  DOI 10.1123/jab.2016-0263  (full text)

Cuenca-Fernandez, R., I.C. Smith, M.J. Jordan, B.R. MacIntosh, G. Lopez-Contreras, R. Arellano and W. Herzog. Non-localized postactivation performance enhancement (PAPE) effects in trained swimmers: a pilot study. Applied Physiology, Nutrition and Metabolism, 42(10): 1122-1125, 2017. (full text)  Altmetric score = 7

O’Connell, J.M, J.M Weir and B.R. MacIntosh. Blood lactate accumulation decreases during the slow component of oxygen uptake without a decrease in muscular efficiency. Pflügers Archiv,  469: 1257-1265, October, 2017. doi:10.1007/s00424-017-1986-y    (full text) 

Fletcher, J.R, and B.R. MacIntosh.  Running economy from a muscle energetics perspective.  June 22, Frontiers in Physiology, 2017. Pg 1-15.  (full text)    over 1800 downloads in first week, and over 5000 by the end of November, 2017 placing this article ahead of 83% of articles ever published by this journal. Views by Mar 2019 >9500. Altmetric rating = 158 (top 5%) as of Mar 16, 2019.

MacIntosh, B.R.  Recent developments in understanding the length dependence of contractile response of skeletal muscle. Invited review. European Journal of Applied Physiology,  117(6): 1059-1071. Online May 2017.  doi:10.1007/s00421-017-3591-3  Altmetric score 30 (top 5%)  (full text)

Stoter, I.K., B.R. MacIntosh, J.R. Fletcher, S. Pootz, I. Zijdewind and F.J. Hettinga. Pacing strategy, muscle fatigue and technique in 1500 m speed skating and cycling time-trials. International Journal of Sport Physiology and Performance, 11(3): 337-343, 2016. DOI:(full text)  Altmetric score = 9

MacIntosh, B.R., Yungblut, S., Frankovich, R., Oh, P. and Fowles, J.  Exercise is medicine Canada: engaging patients in physical activity dialogue – practical tools, CME workshops to assist physicians. Ontario Medical Review, March, 2016  pg 30-33.

Fletcher, J.R. and B.R. MacIntosh. Achilles tendon strain energy in distance running: consider the muscle energy cost. Journal of Applied Physiology, 118: 193-199, 2015  doi: 10.1152/japplphysiol.00732.2014.

Damasceno, M.V., M. Duarte, L.A. Pasqua, A.E. Lima-Silva, B.R. MacIntosh and R. Bertuzzi.  Static stretching alters neuromuscular function and pacing strategy, but not performance during a 3-km running time-trial. PLOSone, 9(6): e99238.  Doi:10.1371/journal.pone.0099238,  2014.  Over 8000 views

Fletcher, J.R. T.R. Pfister and B.R. MacIntosh.  Energy cost of running and Achilles tendon stiffness in man and woman trained runners. Physiological Reports, 1(7): 1-9, e00178, doi: 10.1002/phy2.178, 2013.

Fletcher, J.R., E.M. Groves, T.R. Pfister and B.R. MacIntosh.  Can muscle shortening alone explain the energy cost of muscle contraction in vivo?  European Journal of Applied Physiology, 113(9): 2313-2322, August, 2013; DOI: 10.1007/s00421-013-2665-0.

Teskey, W.J.E., M. Elhabiby, N. El-Sheimy, B.R. MacIntosh. Coherence analysis for movement disorder motion captured by six degree-of-freedom inertial sensing. Journal of Applied Geodesy, 6:65-74, March 2012.

Jouma, V., B.R. MacIntosh and W. Herzog. New insights into force depression in skeletal muscle. Journal of Experimental Biology, 215: 2135-2140, June 2012.

MacIntosh, B.R., R.J. Holash and J.-M. Renaud.  Skeletal muscle fatigue- regulation of excitation-contraction coupling to avoid metabolic catastrophe. (Invited Commentary)  Journal of Cell Science, 125: 2105-2114, 2012.

MacIntosh, B.R., M.-E. Robillard and E.T. Tomaras. Current Commentary: Should postactivation potentiation be the goal of your warm-up? Applied Physiology, Nutrition and Metabolism, 37: 546-550, 2012

Tomaras, E.K and B.R. MacIntosh. Less is more: standard warm-up causes fatigue and less warm-up permits greater cycling power output.  Journal of Applied Physiology, 111: 228-235, July 2011.  Altmetric rating = 88 (March, 2019)

MacIntosh, B.R. S.P. Esau, R.J. Holash and J.R. Fletcher.  Procedures for studying rat in situ skeletal muscle contractile properties. (invited) Journal of Visualized Experiments,  2011. DOI: 10.3791/3167. URL:  www.jove.com/details.php?id=3167.

MacIntosh, B.R., J.J. Glumpak, M.B. MacNaughton and D.E. Rassier.  Pattern of summation with inhibition of calcium release and with fatigue in rat muscle. Muscle & Nerve, 44: 410-417, 2011  

Hettinga, F.J., J.J. de Koning, L. Schmidt, N.A.C. Wind, B.R. MacIntosh and C. Foster.  Optimal pacing strategy: from theoretical modeling to reality in 1500-m speed skating. British Journal of Sports Medicine, 45:30-35, 2011.  Altmetric score = 9

MacIntosh, B.R. and M.R.S. Shahi.  A peripheral governor regulates magnitude of skeletal muscle contractile response.  Invited Review, Applied Physiology, Nutrition and Metabolism, 36: 1-11, 2011. ranked as one of the most often downloaded, for this journal, shortly after publication.

Fletcher, J, Esau, S.P. and B.R. MacIntosh.  Changes in stiffness and running economy in highly trained runners.  European Journal of Applied Physiology, 110(5): 1037-1046, 2010.

Bullimore, S., T Saunders, W. Herzog and B.R. MacIntosh.  Calculation of muscle maximal shortening velocity by extrapolation of the force-velocity relationship: afterloaded versus isotonic release contractions.  Canadian Journal of Physiology and Pharmacology, 88: 937-948, 2010.

Fletcher, J.R., S.P. Esau,  and B.R. MacIntosh.  Economy of running: beyond the measurement of oxygen uptake. Journal of Applied Physiology, 107: 1918-1922, 2009.

Dormer, G.N. G.C. Teskey and B.R. MacIntosh.  Force-frequency and force-length properties in skeletal muscle following unilateral focal ischemic insult in a rat model.  Acta Physiologica, 197: 227-239, 2009.  

Baptista, R.R., E.M. Scheeren, B.R. MacIntosh and M.A. Vaz.  Low-frequency fatigue at maximal and submaximal muscle contractions.  Brazilian Journal of Medical and Biological Research, 42: 380-385, 2009.

Bullimore, S.R., B.R. MacIntosh and W. Herzog.  Is a parallel elastic element responsible for the enhancement of steady-state muscle force following active stretch.  Journal of Experimental Biology, 211: 3001-3008, 2008.

MacIntosh, B.R., M.J. Smith and D.E. Rassier Staircase but not posttetanic potentiation in rat muscle after spinal cord hemisection.  Muscle & Nerve, 38: 1455-1465, 2008. 

MacIntosh, B.R., E.C. Taub, G.N. Dormer and E.K. Tomaras.  Potentiation of isometric and isotonic contractions during high frequency stimulation.  Pflügers Archiv 456:449-458, 2008.

MacNaughton, M.B., and B.R. MacIntosh.  Impact of length during repetitive contractions on submaximal force-length relationships in rat skeletal muscle.  Pflügers Archiv 455:359-366, 2007.

Devrome, A.N. and B.R. MacIntosh.  Double hyperbolic force-velocity relationship in whole mammalian skeletal muscle.  Journal of Applied Physiology, 102:2294-2300, 2007 

MacNaughton, M.B., J.J. Campbell and B.R. MacIntosh.  Dantrolene, like fatigue, has a length dependent effect on submaximal force-length relationships of the rat gastrocnemius muscle.  Acta Physiologica, 189: 271-278, 2007. 

MacIntosh, B.R., D.C. Jones, A.N. Devrome, and D.E. Rassier.  Prediction of summation in incompletely fused tetanic contractions of rat muscle. Journal of Biomechanics, 40: 1066-1072, 2007.

MacNaughton, M.B. and B.R. MacIntosh.  Reports of the length dependence of fatigue are greatly exaggerated. Journal of Applied Physiology, 101:23-29, 2006

MacIntosh, B.R. and M.B. MacNaughton.  The length-dependence of muscle active force: considerations for parallel elastic properties.  Journal of Applied Physiology, 98: 1666-1673, 2005.

MacIntosh, B.R., M. Kim, and K. Svedahl.  Fatigue and optimal conditions for short-term work capacity.  European Journal of Applied Physiology, 92:369-375, 2004.

MacIntosh, B.R. Role of calcium sensitivity modulation in skeletal muscle performance. In News in Physiological Sciences 18: 222-225, 2003.

Svedahl, K. and B.R. MacIntosh.  Anaerobic threshold:  the concept and methods of measurement. Invited Review.  Canadian Journal of Applied Physiology, 28: 299-323, 2003. Was listed as highly cited on journal website; has been cited >500 times, my most cited paper. 

MacIntosh, B.R., P. Rishaug, and K. Svedahl.  Assessment of peak power and short-term work capacity.  European Journal of Applied Physiology, 88:572-579, 2003.

Rassier, D.E. and B.R. MacIntosh.  Sarcomere length-dependence of activity-dependent twitch potentiation in mouse skeletal muscle. BioMed Central – Physiology, 2:19, 2002  (fulltext)   indicated as “highly downloaded”

Rassier, D.E. and B.R. MacIntosh.  Length-dependent twitch contractile characteristics in skeletal muscle. Canadian Journal of Physiology Pharmacology, 80: 993-1000, 2002.

MacIntosh, B.R., S. Esau and K. Svedahl  The lactate minimum test for cycling:  estimation of the maximal lactate steady state. Canadian Journal of Applied Physiology, 27: 232-249, 2002.

MacIntosh, B.R. and D.E. Rassier.  What is fatigue?  Canadian Journal of Applied Physiology, 27: 42-56, 2002.

MacIntosh, B.R. and S.N. Bryan.  Potentiation of shortening and velocity of shortening during repeated isotonic tetanic contractions.  Pflügers Archiv, 443: 804-812, 2002.

Horton, J.F., D. Lindsay and B.R. MacIntosh.  Abdominal muscle characteristics of elite male golfers with and without chronic low back pain.   Medicine and Science in Sports and Exercise, 33: 1647-1654, 2001.

MacIntosh, B.R., S.N. Bryan, P. Rishaug and S. Norris.  Evaluation of the Monark Wingate ergometer by direct measurement of resistance and velocity.  Canadian Journal Applied Physiology, 26: 543-558, 2001.

MacIntosh, B.R. and J.C. Willis.  Force-frequency relationship and potentiation in mammalian skeletal muscle.  Journal of Applied Physiology, 88:2088-2096, 2000.

Rassier, D.E. and B.R. MacIntosh.  Coexistence of potentiation and fatigue in skeletal muscle.  Brazilian Journal of Medical and Biological Research, 33(5):499-508, 2000. My third most cited paper, cited 362 times (Sept, 2108).

MacIntosh, B.R., R.R. Neptune and J.F. Horton.  Cadence, power and muscle activation in cycle ergometry.  Medicine and Science in Sports and Exercise, 32: 1281-1287, 2000.

Rassier, D.E., and B.R. MacIntosh.  Length-dependence of staircase potentiation: interactions with caffeine and dantrolene sodium.  Canadian Journal of Physiology Pharmacology, 78:350-357, 2000.