Scientists are genuinely divided on this question.

Not medical advice — just what the research says.

What's still open

What the evidence found 3 findings
Based on 13 sources:
PubMed peer-reviewed View
NCBI Books institutional View
Facebook fitness page blog View
PMC peer-reviewed View
PubMed peer-reviewed View
PubMed peer-reviewed View
Nutrients journal article on timing of resistance exercise and nutrient intake peer-reviewed View
PMC article on fasted-state skeletal muscle protein synthesis peer-reviewed View
PubMed peer-reviewed View
ResearchGate systematic review and meta-analysis peer-reviewed View
PMC peer-reviewed View
Georgia State University institutional View
PMC peer-reviewed View
Based on 12 sources:
PMC (PubMed Central) peer-reviewed View
Science Direct peer-reviewed View
MDPI peer-reviewed View
PubMed peer-reviewed View
ResearchGate peer-reviewed View
PubMed peer-reviewed View
PubMed study on fasted vs fed aerobic exercise effects peer-reviewed View
ODU Digital Commons thesis on fasted vs fed HIIT exercise institutional View
PubMed peer-reviewed View
MDPI Nutrients peer-reviewed View
British Journal of Nutrition peer-reviewed View
PubMed peer-reviewed View
Based on 13 sources:
PMC peer-reviewed View
PMC peer-reviewed View
EatingWell Facebook news View
ResearchGate peer-reviewed View
PubMed peer-reviewed View
PubMed peer-reviewed View
PMC peer-reviewed View
Instagram blog View
MDPI peer-reviewed View
PubMed peer-reviewed View
PMC article on protein supplementation effects peer-reviewed View
PMC article on post-exercise muscle protein remodeling peer-reviewed View
ResearchGate publication on muscle protein dynamics peer-reviewed View
What research hasn't answered 3 gaps
PMC (PubMed Central) peer-reviewed View
Science Direct peer-reviewed View
MDPI peer-reviewed View
PubMed peer-reviewed View
ResearchGate peer-reviewed View
PubMed peer-reviewed View
NCBI Books institutional View
Facebook fitness page blog View
PMC peer-reviewed View
PubMed peer-reviewed View
Sources 19 findings
argumentation Unknown
argumentation Unknown
tree-leaf argumentation
tree-leaf argumentation
tree-leaf argumentation
tree-leaf argumentation
tree-leaf argumentation
tree-leaf argumentation
tree-leaf argumentation
tree-leaf argumentation
tree-leaf argumentation
tree-leaf argumentation
tree-leaf argumentation
tree-leaf argumentation
tree-leaf argumentation
tree-leaf argumentation
tree-leaf argumentation
argumentation Unknown
argumentation Unknown
Push back on this read

Think the evidence is read wrong? Present your counter-evidence and we'll evaluate it against the 45 sources behind this analysis.

Related questions
Does high rep training build as much muscle as heavy weights? Are cold plunges actually beneficial? Are morning workouts better? Is running bad for your knees?

Heard something that sounds off?

Generated by reaso.ai's editorial pipeline: claim restated, scientific consensus classified via 3-run majority vote, 19 findings enriched with attribution and study type, narrative written in neutral voice. No individual researcher has signed off on this specific analysis — see methodology for how the pipeline works. Built with Claude Sonnet by Anthropic. Updated April 16, 2026. How we do this →

Written by AI. Sources are linked for verification.