From:  Exercise and brain health in long COVID: mechanisms and therapeutic implications for neuropsychiatric disorders

 Evidence stratification of exercise effects across psychiatric and neurological domains in long COVID.

ConditionIndirect evidence (non-long COVID populations)Direct long COVID evidenceExpert-opinion/consensus recommendationsKey evidence gaps
Depression/MDD symptomsStrong evidence from MDD (RCTs, SRs, MAs) showing reductions in depressive symptoms and relapse riskLimited RCT evidence in long COVID; small trials suggest improvements in mood and QoL but no disorder-specific endpointsExercise recommended as adjunctive therapy, preferably supervised moderate-intensity aerobic ± resistance trainingLack of large RCTs in long COVID with validated psychiatric outcomes; unclear dose–response relationship
Anxiety symptomsRobust evidence in anxiety disorders (RCTs, MAs) showing reduced anxiety sensitivity and physiological arousalVery limited post-COVID specific data; heterogeneous symptom-level outcomes reported in rehabilitation studiesModerate-intensity aerobic exercise recommended; individualized pacing advisedNo long COVID specific anxiety disorder trials; unclear effect on severe anxiety phenotypes
PTSD Strong evidence from PTSD populations supporting aerobic and mind–body interventionsNo direct long COVID trialsExercise as adjunct to trauma-focused therapy; yoga/tai chi often recommendedNo long COVID specific PTSD studies; unclear interaction with post-viral neuroinflammation
Schizophrenia spectrum symptomsStrong indirect evidence supporting improvements in negative symptoms, cognition, and cardiometabolic healthNo direct evidenceStructured supervised exercise programs recommendedNo long COVID specific studies; adherence in post-viral fatigue unknown
Bipolar spectrum symptomsLimited psychiatric evidence suggests benefits but risk of mood destabilizationNo direct evidence in long COVIDLow-to-moderate intensity exercise with clinical monitoring recommendedNo data in post-viral populations; safety profile unclear
Neurological dysfunction (motor/cognitive sequelae)Strong evidence from stroke, MS, neurodegeneration showing benefits in mobility, cognition, and functionSparse direct evidence; small rehabilitation studies suggest improvements in function but limited neurological specificityStructured aerobic + task-oriented rehabilitation recommended with supervisionNo disease-specific long COVID neurological trials; unclear long-term neuroplastic effects
Cognitive impairment (“brain fog”)Strong indirect evidence in mild cognitive impairments, dementia prevention, and depression-related cognitive dysfunctionSmall RCTs and SRs show inconsistent or modest improvements in cognition; many negative or neutral findingsModerate aerobic exercise with gradual progression suggested to support attention and processing speedLack of standardized cognitive endpoints; unclear responders vs. non-responders; symptom fluctuation not addressed
Autonomic dysfunction Indirect evidence from autonomic disorders supports recumbent exercise and graded verticalizationVery limited direct evidence; mostly observational rehabilitation dataRecumbent or semi-recumbent aerobic training, slow progression, close monitoring advisedLack of RCTs; unclear optimal progression protocols and safety thresholds

This table presents an evidence map of exercise interventions across psychiatric and neurological domains in long COVID, categorizing the literature into four levels: (i) indirect evidence from non-long COVID populations, (ii) direct long COVID evidence, (iii) expert-opinion or consensus-based recommendations, and (iv) key evidence gaps. It highlights the imbalance between strong mechanistic and indirect support and the limited availability of high-quality, disorder-specific evidence in long COVID, and serves as a framework for the critical appraisal developed in the subsequent sections. This table provides a synthetic evidence overview; detailed references and critical appraisal of each evidence category are presented in the corresponding sections of the manuscript. MDD: major depressive disorder; RCTs: randomized controlled trials; SRs: systematic reviews; MAs: meta-analyses; QoL: quality of life; PTSD: post-traumatic stress disorder; MS: multiple sclerosis.