Dr Leigh Breen PhD, FHEA, FECSS

Dr Leigh Breen

School of Sport, Exercise and Rehabilitation Sciences
Exercise & Health Theme Lead
Associate Professor: Metabolic and Molecular Physiology

Contact details

School of Sport, Exercise and Rehabilitation Sciences
University of Birmingham
B15 2TT

Dr Leigh Breen is a leading expert in the field of skeletal muscle metabolism. His group are nationally and internationally renowned for their work into the metabolic and molecular regulation of skeletal muscle plasticity and function in health and disease, as well as specific expertise in the role of dietary protein as a key modulator of skeletal muscle metabolism. 

Feedback and office hours

Dr Breen's office hours are 3-4pm on Tuesdays. Dr Breen is located in the School of Sport, Exercise and Rehabilitation Sciences.


  • PhD (Exercise Metabolism) – University of Birmingham 2010
  • MSc by Research – Manchester Metropolitan University 2007
  • BSc(hons) Sport and Exercise Sciences - Manchester Metropolitan University 2006


Dr Breen joined the University of Birmingham in 2013 as a Lecturer and is currently an Associate Professor in Metabolic and Molecular Physiology. His research group are based in the School of Sport, Exercise and Rehabilitation Sciences, and is also affiliated to the MRC-ARUK Centre of Musculoskeletal Ageing and the NIHR Biomedical Research Centre at University of Birmingham. 

Since his appointment in 2013, Dr Breen has been PI or Co-I on successful project grants from RCUK (e.g., BBSRC New Investigator) and charitable foundations (e.g., Dunhill Medical Trust) to the tune of ~£2.5 million. He has published >80 peer-reviewed articles (H-index of 30, i10 index 42, >6000 cites) and is a regular speaker at national and international conferences. 

Prior to joining University of Birmingham, Dr Breen completed his PhD training at UoB in 2010 under the supervision of experts in the field of Exercise Metabolism. In 2011, Dr Breen received a Young Investigator of the Year Award at the European Congress for Sports Sciences (ECSS) for work involving stable isotope tracers to study muscle protein metabolism in exercising humans. Subsequently, Dr Breen undertook a post-doctoral fellowship in the internationally distinguished laboratory of Prof Stuart Phillips (McMaster University, Canada) investigating the influence of exercise, nutrition and inactivity on muscle metabolic health across the lifespan. During this time, Dr Breen developed a keen interest in musculoskeletal ageing, and undertook extensive specialist training in stable isotope tracer methodology and muscle biochemistry techniques to characterise mechanisms of skeletal muscle remodelling.


Dr Breen teaches the following modules on the BSc Sport, Exercise and Health Sciences.

Metabolic Perspectives in Health and Disease (Year 3) – Module Lead

Sports Nutrition (Year 2) – Co-contributor 

In addition, Dr Breen contributes to the Neuromuscular Adaptations to Training module on the MSc by Research.

Postgraduate supervision

In 2021, Dr Breen’s research group consists of 2 Post-Doctoral Research Fellows, 5 PhD students and 1 MSc by Research student. 

Dr Breen has successfully supervised 3 PhD students and >10 MSc by Research students welcomes applications from potential post-graduate students with interests aligned to his research agenda.


The overarching goal of Dr Breen’s research is to understand regulatory mechanisms of skeletal muscle plasticity and develop targeted exercise and nutritional approaches to enhance skeletal muscle remodelling and physical performance in health and disease. Dr Breen is actively working on the following specific projects: 

  • The role of chronological and biological ageing on muscle atrophy (e.g., Master Athletes to Obese Old).
  • The impact of disuse (e.g., reduced activity, immobilization and bed rest) on muscle atrophy and the discovery of novel nutritional countermeasures.
  • Mechanisms of muscle atrophy in chronic inflammatory disease conditions (liver disease, cancer).
  • The muscle anabolic properties of novel, sustainable dietary protein sources.
  • Physical activity and dietary intake habits of older arthroplasty patients.

Other activities

In 2019 Dr Breen was awarded Fellow status with the European College of Sports Sciences. 

Dr Breen has acted as a consultant for various industry bodies (e.g., Dairy UK, Nutraingredients) and has received research funding from industry stakeholders including Volac LTD and Myprotein.


Recent Publications (selected from >80 in total) 

  • S.L. Allen, R. N. Marshall, S. J. Edwards, J. M. Lord, G. G. Lavery, L. Breen. The effect of young and old ex vivo human serum on cellular protein synthesis and growth in an in vitro model of ageing. Am J Physiol Cell Physiol. 2021 (online ahead of print).
  • P. T. Morgan, L. Breen. The role of protein hydrolysates for exercise-induced skeletal muscle recovery and adaptation: a current perspective. Nutr Metab. 2021. 18(1):44
  • P. T. Morgan, D. O. Harris, R. N. Marshall, J. I. Quinlan, S. J. Edwards S. L. Allen, L. Breen. Protein Source and Quality for Skeletal Muscle Anabolism in Young and Older Adults: A Systematic Review and Meta-Analysis. J Nutr. 2021 (online ahead of print)
  • Shad BJ, Thompson JL, Mckendry J, Holwerda AM, Elhassan YS, Breen L, van Loon LJC, Wallis GA Daily Myofibrillar Protein Synthesis Rates in Response to Low- and High-Frequency Resistance Exercise Training in Healthy, Young Men. Int J Sport Nutr Exerc Metab. 2021: 1-8.
  • Smeuninx B, Elhassan YS, Manolopoulos KN, Sapey E, Rushton AB, Edwards SJ, Morgan PT, Philp A, Brook MS, Gharahdaghi N, Smith K, Atherton PJ, Breen L. The effect of short-term exercise prehabilitation on skeletal muscle protein synthesis and atrophy during bed rest in older men. J Cachexia Sarcopenia Muscle. 2021. 12(1):52-69.
  • Morgan PT, Smeuninx B, Breen L. Exploring the Impact of Obesity on Skeletal Muscle Function in Older Age. Front Nutr. 2020. 7:569904.
  • Allen SL, Quinlan JI, Dhaliwal A, Armstrong MJ, Elsharkawy AM, Greig CA, Lord JM, Lavery GG, Breen L. Sarcopenia in Chronic Liver Disease: Mechanisms and Countermeasures. Am J Physiol Gastrointestinal Liver Physiol. 2020 (online ahead of print).
  • Edwards SJ, Smeuninx B, Mckendry J, Nishimura Y, Luo D, Marshall RN, Perkins M, Ramsay J, Joanisse S, Philp A, Breen L. High-dose leucine supplementation does not prevent muscle atrophy or strength loss over 7 days of immobilization in healthy young males. Am J Clin Nutr. 2020.112(5):1368-1381.
  • Marshall RN, Smeuninx B, Morgan PT, Breen L. Nutritional Strategies to Offset Disuse-Induced Skeletal Muscle Atrophy and Anabolic Resistance in Older Adults: From Whole-Foods to Isolated Ingredients. Nutrients. 2020. 12(5):1533.
  • Luo D, Edwards S, Smeuninx B, McKendry J, Nishimura Y, Perkins M, Philp A, Joanisse S, Breen L. Immobilization Leads to Alterations in Intracellular Phosphagen and Creatine Transporter Content in Human Skeletal Muscle. Am J Physiol Cell Physiol. 2020 (online ahead of print).
  • Marshall RN, Morgan PT, Martinez-Valdes E, Breen L. Quadriceps muscle electromyography activity during physical activities and resistance exercise modes in younger and older adults. Exp Gerontol. 2020. 136:110965.
  • Smeuninx B, Greig CA, Breen L. Amount, Source and Pattern of Dietary Protein Intake Across the Adult Lifespan: A Cross-Sectional Study. Front Nutr. 2020. 7:25.
  • D'Hulst G, Soro-Arnaiz I, Masschelein E, Veys K, Fitzgerald G, Smeuninx B, Kim S, Deldicque L, Blaauw B, Carmeliet P, Breen L, Koivunen P, Zhao SM, De Bock K. PHD1 controls muscle mTORC1 in a hydroxylation-independent manner by stabilizing leucyl tRNA synthetase. Nat Commun. 2020. 11(1):174.
  • Morehen S, Smeuninx B, Perkins M, Morgan P, Breen L. Pre-Sleep Casein Protein Ingestion Does Not Impact Next-Day Appetite, Energy Intake and Metabolism in Older Individuals. Nutrients. 2019.12(1):90.
  • J. McKendry, B. Shad, B. Smeuninx, S. Oikawa, G. Wallis, C. Greig, S. M. Phillips, L. Breen.  Comparable ratesof Integrated Myofibrillar Protein Synthesis Between Endurance-Trained Master Athletes and Untrained Older Individuals. Frontiers Physiology. 2019. 30;10:1084.
  • J. McKendry, S. Joanisse, S. Baig, B. Liu, G. Parise, C, Greig, L. Breen.  Superior Aerobic Capacity and Indices of Skeletal Muscle Morphology in Chronically Trained Master Endurance Athletes Compared with Untrained Older Adults. J Gerontol: Biol Sci. 2019. 75(6):1079-1088.
  • Nicholson, T. Church, C. Tsintzas, K. Jones, R. Breen, L. Davis, E.T. Baker, D.J. Jones, S.W. Vaspin promotes insulin sensitivity of elderly muscle and is upregulated in obesity. J Endocrinol. 2019. pii: JOE-18-0528.R3.
  • Wilson, D, L. Breen, J. M. Lord, E. Sapey. The challenges of muscle biopsy in a community-based geriatric population. BMC Medicine. 2018 Nov 26;11(1):830.
  • B. Smeuninx, Y. Nishimura, J. McKendry, M. Limb, K. Smith, P. J. Atherton, L. Breen. The Effect of Acute Oral Phosphatidic Acid Ingestion on Myofibrillar Protein Synthesis and Intracellular Signaling in Older Males. Clin Nutr. 2018. S0261-5614(18)31182-8
  • J. McKendry, L. Breen, B. Shad, C. A. Greig. Muscle Morphology and Performance in Master Athletes: A Systematic Review. Ageing Research Reviews. 2018. 30;45:62-82
  • B. Smeuninx, J. McKendry, D. Wilson, U. Martin, L. Breen. Age-related anabolic resistance of myofibrillar protein synthesis is exacerbated in obese inactive individuals. J Clin Endocrinology & Metabolism. 2017. 102(9):3535-3545
  • B. Shad, J. Thompson, L. Breen. Does the muscle protein synthetic response to exercise and amino acid-based nutrition diminish in old age? A systematic review. Am J Physiology – Endocrinology and Metabolism. 2016. 311(5): E803-E817

View all publications in research portal