The Study
Investigating the Impact of Glycogen-Depleting Exercise Combined with Prolonged Fasting on Autophagy and Cellular Health in Humans: A Randomised Controlled Crossover Trial
This study tested what happens to the body when people fast for three days, with or without exercise, by measuring tiny changes in their blood cells. It shows that these actions might change how cells clean themselves, but it doesn't prove that fasting makes you live longer or prevents sickness.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
This study tested if going without food for three days helps your body clean out damaged cell parts, and if doing hard exercise right before fasting makes it work even better.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 562 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1These changes suggest the body switches to repair mode during prolonged fasting — a natural process that may help slow aging and reduce disease risk.
- 2After three days of only drinking water, cells showed more cleanup activity (autophagy), IGF-1 dropped by 30–40%, and ketones rose over 5 times.
- 3Exercise before fasting didn’t make cleanup any stronger.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Nutrients
Year
2024
Authors
A. Masedunskas, Isabella de Ciutiis, Leanne K Hein, Anjie Ge, Yvonne X Kong, Miao Qi, Drishya Mainali, Lara Rogerson-Wood, Cynthia M Kroeger, Yvonne A Aguirre Candia, M. L. Cagigas, Tian Wang, D. Hutchinson, Angelo Sabag, F. Passam, Laura Piccio, T. Sargeant, Luigi Fontana
Related Content
Claims (6)
In humans, autophagy is primarily triggered by a reduction in energy intake, not by when meals are consumed during the day.
In healthy adults, doing intense endurance exercise right before a three-day water fast does not increase autophagic flux in immune cells more than the fast alone.
A three-day water-only fast increases autophagic flux in immune cells from the blood of healthy adults with normal body weight, as detected by lysosomal inhibition markers.
A three-day water-only fast lowers IGF-1 levels by 30–40% in healthy adults, reduces mTOR pathway activity, and increases cellular maintenance processes.
After three days of drinking only water, healthy adults show more than five times higher levels of beta-hydroxybutyrate in their blood, which reflects a switch in the body’s primary energy source from glucose to fat.
A three-day water-only fast changes the levels of proteins and metabolites in the blood of healthy adults, specifically those involved in inflammation, oxidative stress, and cellular stress response pathways.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.