Systematic review shows that physical and mental fatigue indirectly alter physical effort decisions in healthy adults, indicating distinct pathways govern willingness to exert effort.
Key Points
To synthesize evidence on whether and how experimentally induced physical and mental fatigue, alone or combined with other factors, affect physical effort-based decision-making in healthy adults.
Conducted a systematic search per PRISMA guidelines across PubMed, Scopus, Web of Science, CENTRAL, and EBSCOhost through May 12, 2026.
Identified and synthesized 10 experiments from 9 articles evaluating physical effort decision-making following experimentally induced physical or mental fatigue in healthy adults.
Neither physical nor mental fatigue demonstrated consistent direct effects on physical effort choices across the analyzed experiments.
Physical fatigue functioned as a moderating factor by amplifying the subjective cost of effort, thereby increasing preference for less demanding options.
Mental fatigue operated via a mediating mechanism, increasing perceived effort and shifting benefit–cost evaluations during decision-making.