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The Long Game with Nicklas Rossner

How Running Completely Changes The Human Body

Mar 17, 2026 · 8 min

FREE Running Limiter Quiz + Custom Training Plan: https://nicklasrossner.com/run-limiter/


In this episode, I break down the science of what actually happens inside your body from your very first run to long-term health and longevity.

You’ll learn:

• What happens in your brain after just ONE run (and why you instantly feel better)
• The real science behind “runner’s high”
• How running builds mitochondria — the tiny power plants that make you faster
• Why stronger tendons make you more efficient and injury-resistant
• How your heart physically remodels itself with training
• Why VO₂ max might be the single strongest predictor of lifespan
• Exactly how much you need to run for mental health, performance, and longevity

And most importantly — how to get all the benefits without overdoing it and ruining your progress.

My name is Nicklas. I’m a sports scientist, physiotherapist, and former professional triathlete. I translate complex exercise science into simple, practical strategies you can actually use.

If you’ve ever wondered:

How much running is enough?
Do I need intervals?
Can I run too much?
Is running actually good for long-term health?

This episode gives you the complete science-backed answer.

Run once to feel better today.
Run consistently to get fitter in months.
Run smart to stay healthy for decades.


References:

Mandsager K, Harb S, Cremer P, Phelan D, Nissen SE, Jaber W. Association of Cardiorespiratory Fitness With Long-term Mortality Among Adults Undergoing Exercise Treadmill Testing. JAMA Netw Open. 2018 Oct 5;1(6):e183605

Crowley E, Powell C, Carson BP, W Davies R. The Effect of Exercise Training Intensity on VO2max in Healthy Adults: An Overview of Systematic Reviews and Meta-Analyses. Transl Sports Med. 2022

Pereira Hugo Vieira , et. al.: Systematic Review of Psychological and Behavioral Correlates of Recreational Running, Frontiers in Psychology, Volume 12 - 2021

Umakantha Monika* and John Romate, The Lesser-Known Phenomenon of Sports: A Systematic Review of Runners’ High, Indian Journal of Psychological Science Vol-19, No. 2, (July-2024)

Hughes DC, Ellefsen S, Baar K. Adaptations to Endurance and Strength Training. Cold Spring Harb Perspect Med. 2018 Jun 1;8(6):a029769.

Kutac, P., Bunc, V., Buzga, M. et al. The effect of regular running on body weight and fat tissue of individuals aged 18 to 65. J Physiol Anthropol 42, 28 (2023).

Statuta SM, Asif IM, Drezner JARelative energy deficiency in sport (RED-S)British Journal of Sports Medicine 2017;**51:**1570-1571.

Lee, D, Lavie, C, Vedanthan, R. Optimal Dose of Running for Longevity: Is More Better or Worse?∗. JACC. 2015 Feb, 65 (5) 420–422.

Astorino, Todd A; Allen, Ryan P; Roberson, Daniel W; Jurancich, Matt. Effect of High-Intensity Interval Training on Cardiovascular Function, V̇o2max, and Muscular Force. Journal of Strength and Conditioning Research 26(1):p 138-145, January 2012.

Spiering BA, Mujika I, Sharp MA, Foulis SA. Maintaining Physical Performance: The Minimal Dose of Exercise Needed to Preserve Endurance and Strength Over Time. J Strength Cond Res. 2021 May 1;35(5):1449-1458.

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