Cover art for the episode 190 – Zone 2 Running: when less exercise might count for more

Podcast episode

190 – Zone 2 Running: when less exercise might count for more

Dr. Christopher Labos Jun 25, 2026 44 min

Publisher text and links (RSS) — partners, promos, listening apps

Are light runs (Zone 2 runs) better than heavier workouts?

Sophie goes on a semi-manic tangent in her most enthusiastic episode yet to answer whether less intense exercise might actually help your fitness level, aerobic threshold and mitochondrial efficiency.

Also, Chris tells a funny marathon story and a viewer question tries to fact-check to the fact checkers on whether walking and running burn the same amount of energy.

Become a supporter of our show today either on Patreon or through PayPal!

Thank you! http://www.patreon.com/thebodyofevidence/ https://www.paypal.com/donate?hosted_button_id=9QZET78JZWCZE Email us your questions at thebodyofevidence@gmail.com.

Hosts: Christopher Labos & Sophie Tseng Pellar Editor: Robyn Flynn Researcher: Auriane Journet Theme music: “Fall of the Ocean Queen“ by Joseph Hackl Rod of Asclepius designed by Kamil J.

Przybos Chris’ book, Does Coffee Cause Cancer?: https://ecwpress.com/products/does-coffee-cause-cancer Obviously, Chris is not your doctor (probably).

This podcast is not medical advice for you; it is what we call information.

References: 1.

Storoschuk, K.

L., Moran-MacDonald, A., Gibala, M.

J., & Gurd, B.

J. (2025).

Much Ado About Zone 2: A Narrative Review Assessing the Efficacy of Zone 2 Training for Improving Mitochondrial Capacity and Cardiorespiratory Fitness in the General Population: KL Storoschuk et al.

Sports Medicine, 55(7), 1611-1624. 2.

Mølmen, K.

S., Almquist, N.

W., & Skattebo, Ø. (2025).

Effects of exercise training on mitochondrial and capillary growth in human skeletal muscle: a systematic review and meta-regression.

Sports Medicine, 55(1), 115-144. 3.

Inglis, E.

C., Iannetta, D., Rasica, L., Mackie, M.

Z., Keir, D.

A., Macinnis, M.

J., & Murias, J.

M. (2024).

Heavy-, severe-, and extreme-, but not moderate-intensity exercise increase V̇o 2max and thresholds after 6 wk of training.

Medicine & Science in Sports & Exercise, 56(7), 1307-1316. 4.

McConell, G.

K., Wadley, G.

D., Le plastrier, K. and Linden, K.

C. (2020), Skeletal muscle AMPK is not activated during 2 h of moderate intensity exercise at ∼65% in endurance trained men.

J Physiol, 598: 3859-3870. https://doi.org/10.1113/JP277619 5.

Meixner, B., Filipas, L., Holmberg, H.

C., & Sperlich, B. (2025).

Zone 2 Intensity: A Critical Comparison of Individual Variability in Different Submaximal Exercise Intensity Boundaries.

Translational sports medicine, 2025, 2008291. https://doi.org/10.1155/tsm2/2008291 6.

Harber MP, et al.

Impact of Cardiorespiratory Fitness on All-Cause and Disease-Specific Mortality: Advances Since 2009.

Progress in Cardiovascular Diseases 2017;60(1):11-20.

PubMed 28286137 7.

Kodama S, Saito K, Tanaka S, et al.

Cardiorespiratory Fitness as a Quantitative Predictor of All-Cause Mortality and Cardiovascular Events in Healthy Men and Women: A Meta-analysis.

JAMA 2009;301(19):2024-2035.

PubMed 19454641