{"id":"75b582a7-e73e-5bf6-a599-3b4fed75bce8","stable_key":"ea2f0904-ab2c-5d1e-a3d4-3f7ecdd70cd6:caf-creatine-pcr","predicate":"increases_despite_caffeine","statement":"Creatine alone and creatine plus caffeine each increased muscle phosphocreatine by 4–6%; measured ATP stayed constant.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"8252562b-7443-5ee6-a9de-e85677d65c7c","mechanism_event_label":"Caffeine did not block the measured phosphocreatine increase.","subject":{"id":"9f5df558-ed3d-5cda-b5ca-0f90f7aa6a8c","slug":"creatine","display_name":"Creatine","entity_type_key":"small_molecule"},"object":{"id":"f168ce17-dc6b-58ee-941c-7d4b8bce4a88","slug":"muscle-phosphocreatine-concentration","display_name":"Skeletal-muscle phosphocreatine concentration","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"8252562b-7443-5ee6-a9de-e85677d65c7c","stable_key":"ea2f0904-ab2c-5d1e-a3d4-3f7ecdd70cd6:caf-creatine-pcr-event","event_type":"observed_relationship","label":"Caffeine did not block the measured phosphocreatine increase.","description":"Creatine alone and creatine plus caffeine each increased muscle phosphocreatine by 4–6%; measured ATP stayed constant.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"9f5df558-ed3d-5cda-b5ca-0f90f7aa6a8c","slug":"creatine","display_name":"Creatine","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"f168ce17-dc6b-58ee-941c-7d4b8bce4a88","slug":"muscle-phosphocreatine-concentration","display_name":"Skeletal-muscle phosphocreatine concentration","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"ef028472-7c33-583d-b52e-40676004d370","slug":"caffeine","display_name":"Caffeine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"c081984a-e118-582f-ac46-6a767f8f0bf2","slug":"phosphocreatine","display_name":"Phosphocreatine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"58b974f1-d389-5bf6-81cd-889c44442c42","slug":"atp","display_name":"ATP","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Nine healthy men; six-day creatine loading 0.5 g/kg/day, with or without caffeine 5 mg/kg/day; intermittent knee-extensor testing.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Small protocol-specific trial. Creatine accumulation and performance were separate endpoints.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Caffeine collection; salts, coffee, species and coexposure contexts retain their identities.","comparator":null,"unit":null,"notes":"","entity":{"slug":"caffeine","display_name":"Caffeine","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"Caffeine did not block the measured phosphocreatine increase.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Caffeine counteracts the ergogenic action of muscle creatine loading. · 1996 · https://pubmed.ncbi.nlm.nih.gov/8929583/ · DOI 10.1152/jappl.1996.80.2.452","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"ba7a0a51-bbc3-56f1-9041-bf10112de8bb","evidence_kind":"source_excerpt","locator":"Lines 444-450","start_line":444,"end_line":450,"excerpt":"## caf-creatine-pcr\nCaffeine did not block the measured phosphocreatine increase.\nCreatine alone and creatine plus caffeine each increased muscle phosphocreatine by 4–6%; measured ATP stayed constant.\nModel: Nine healthy men; six-day creatine loading 0.5 g/kg/day, with or without caffeine 5 mg/kg/day; intermittent knee-extensor testing.\nLimitations: Small protocol-specific trial. Creatine accumulation and performance were separate endpoints.\nEvidence access: Primary abstract\nCaffeine counteracts the ergogenic action of muscle creatine loading. · 1996 · https://pubmed.ncbi.nlm.nih.gov/8929583/ · DOI 10.1152/jappl.1996.80.2.452","model_system":"Nine healthy men; six-day creatine loading 0.5 g/kg/day, with or without caffeine 5 mg/kg/day; intermittent knee-extensor testing.","directness":"reported_statement","verification_status":"source_derived_draft","notes":"Original curation paraphrase; evidence access stated with the claim.","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"40a654db-878c-5471-bc6c-88f4f52599c0","stable_key":"import-ea2f0904-ab2c-5d1e-a3d4-3f7ecdd70cd6","title":"Caffeine: receptors, metabolism, nutrient interactions, adaptation and discovery questions (2026-09-18)","document_type":"imported_text","citation_label":"AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text.","file_path":"","sha256":"780d73d4abd45a0284d2cc0c646dbe8432ae347362891a4b98a19a61341a7325","revision_id":"f36ffb0a-d6df-522f-b783-5e30214b9e26","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}