Jimmy Bagley Headshot

Jimmy Bagley

Associate Professor
Phone: (415) 338-3363
Email: jrbagley@sfsu.edu
Location: Gym 139

Dr. Jimmy Bagley is an Associate Professor of Kinesiology and Director/Founder of the Muscle Physiology Lab (MPL), Co-Director of the Exercise Physiology Lab, and Research Director of the Strength and Conditioning Lab at SF State. Dr. Bagley’s research interests are diverse, and his overarching goal is “to better understand human health and performance”.

Bagley Bio

Dr. Bagley’s primary research area focuses on muscle physiology, specifically investigating how muscles grow (hypertrophy) with exercise and shrink (atrophy) with disuse in human and animal models (Bagley, et al. 2020; Bagley, et al. 2023; Machek, et al. 2020; Machek, et al. 2021; Lyons et al., 2018). His Lab measures structural cell size and myonuclear changes using confocal microscopy (Machek, et al. 2021). His second area of research is on the human gut microbiome’s impact on sport and exercise performance, specifically, investigating the connection between the gut microbiota and exercise capacity in athletes (Grosicki, et al. 2019). Dr. Bagley’s third area of research is investigating the efficacy of health and fitness technologies, including virtual reality (VR) exercise interventions (Stewart, et al. 2022) and metabolic equipment (Gasmin, et al. 2020; Lorenz, et al. 2021). See his Google Scholar Page for a full list of publications.

Dr. Bagley earned a PhD in Human Bioenergetics from Ball State University, MS in Kinesiology from Cal State University-Fullerton, and BS in Kinesiology from Cal Poly-San Luis Obispo. He is an active member of the American College of Sports Medicine (ACSM), American Physiological Society (APS), and National Strength and Conditioning Association (NSCA). Follow the MPL on Instagram and X: @MusclePhysLab



Selected Publications

Muscle Physiology & Hypertrophy Mechanisms

  • Bagley JR, Denes LT, McCarthy JJ, Wang ET, and KA Murach (2023). The Myonuclear Domain in Adult Skeletal Muscle Fibres: Past, Present, and Future. Journal of Physiology. Vol. 601(4), 723-741 PubMed:
  • Bagley JR, Burghardt KJ, McManus R, Howlett B, Costa PB, Coburn JW, Arevalo JA, Malek MH, and AJ Galpin (2020). Epigenetic responses to acute resistance exercise in trained vs sedentary men. Journal of Strength & Conditioning Research, 34(6):1574-1580 PubMed: 32459413
  • Bathgate KE, Bagley JR, Jo E, Talmadge RJ, Tobias IS, Brown LE, Coburn JW, Arevalo JA, Segal NL, and AJ Galpin (2018). Muscle health and performance in monozygotic twins with 30 years of discordant exercise habits.European Journal of Applied Physiology, 118(10), 2097-2110 PubMed: 30006671
  • Murach KA and JR Bagley (2016). Skeletal muscle hypertrophy with concurrent exercise training: contrary evidence for an interference effect. Sports Medicine, 48 (8), 1029-39 PubMed: 26932769


Gut Microbiome in Sport & Exercise Performance 

  • Grosicki GJ, Durk RP, and JR Bagley (2020). Rapid gut microbiome changes in a world-class ultramarathon runner. Physiological Reports. 7(24) PubMed: 31872558
  • Durk RP, Castillo E, Márquez-Magaña L, Grosicki GJ, Bolter ND, Lee CM, and JR Bagley (2019). Relationship between cardiorespiratory fitness and relative gut microbiota composition in healthy adults. International Journal of Sport Nutrition and Exercise Metabolism, 29(3): 249-253 PubMed: 29989465


Active Virtual Reality Gaming (AVRG) and Health Technologies

  • Stewart TH, Villanueva K, Hahn A, Ortiz-Delatorre J, Wolf C, Nguyen R, Bolter ND, Kern M, and JR Bagley (2022). Actual vs Perceived Exertion during Active Virtual Reality Game Exercise. Frontiers in Rehabilitation Sciences, Vol. 3: 887740. PubMed: 36189005
  • Hood KM, Marr C, Kirk-Sorrow J, Farmer J, Lee CM, Kern M, and JR Bagley (2019). Validity and reliability of a Wi-Fi smart scale to estimate body composition. Health & Technology, 9:839-846.
  • Gomez DH, Bagley JR, Bolter N, Kern M, and CM Lee (2018). Metabolic cost and exercise intensity during active virtual reality gaming. Games for Health Journal, 7(5), 3010-316. PubMed: 30325233


Authored Textbooks/Chapters

  • Bagley JR and CM Lee (2020). Laboratory Experiences in Exercise Physiology (1st Ed.). Kendall-Hunt Publishing, Dubuque, IA.
  • Galpin AJ and JR Bagley (2016). “Chapter 11: Torso Exercises”. Strength Training (2nd Ed.) National Strength and Conditioning Association (NSCA), Lee E. Brown (Editor). Human Kinetics, Champaign, IL. Pages 241-266.




  • KIN 355 - Science, Sport & Fitness
  • KIN 482 - Exercise Physiology
  • KIN 555 - Exercise Testing & Prescription
  • KIN 683 - Advanced Exercise Physiology
  • KIN 690 - Internship in Fitness and Wellness
  • KIN 781 - Muscle Physiology


Interest in Joining the Muscle Physiology Lab?

Contact Dr. Bagley via email or setup and office hours appointment. Checkout the SFSU MS in Kinesiology website for information on applying to our program.