The Study
Cardiorespiratory, enzymatic and hormonal responses during and after walking while fasting
This study compared two ways of walking: after eating breakfast and after not eating. It measured things like stress hormones and energy use during and after walking. It found small differences, but it didn’t measure if people actually lost more fat. So we know what happened right after walking, but not if it made people thinner over time.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Scientists tested if walking first thing in the morning without eating burns more fat than walking after breakfast.
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 559 / 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.
- 1Even though fasting raised fat in the blood and stress hormones, the body didn’t use more of it for energy—so no extra fat loss occurred.
- 2Walking after eating lowered blood sugar during exercise.
- 3Walking without eating raised stress hormones (cortisol) and fat in the blood—but didn’t burn more fat.
- 4Heart rate and oxygen use were the same in both cases.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
PLoS ONE
Year
2018
Authors
J. Vilaça-Alves, Fernanda Muller, Claudio Rosa, R. Payan-Carreira, R. Lund, Filipe Matos, Nuno Miguel de Figueiredo Garrido, F. Saavedra, V. Machado Reis
Related Content
Claims (6)
When people walk in a fasted state versus a fed state but consume the same calories and burn the same amount of energy, the amount of fat lost is the same.
In healthy young active men, walking at a low intensity while fasted raises free fatty acid levels more than walking after eating, but this does not result in higher fat burning during the walk.
In healthy young active men, walking for 45 minutes after fasting raises cortisol and lowers the testosterone-to-cortisol ratio during recovery compared to walking after eating a standardized meal.
When healthy young active men walk at a low intensity after eating a standardized meal, their blood glucose levels during the walk are lower than when they walk after fasting, showing that food intake increases insulin-mediated glucose uptake.
In healthy young active men, walking at a low intensity whether or not they have eaten recently results in the same levels of oxygen use, heart rate, and respiratory exchange ratio during and after the walk.
In healthy young active men, walking at a low intensity after eating does not result in higher fat oxidation than walking before eating, even though the body's fuel sources and hormones differ between these two states.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.