{"id":"51fb93eb-1d04-5133-8b19-9a678ce5ee06","stable_key":"b3c3f45a-50fb-5b79-98d7-5e5228df00db:cold-seasonal-catecholamine-fall","predicate":"preserves_measured_pool","statement":"Mean plasma noradrenaline fell significantly from autumn to spring and more so in winter swimmers, but with no statistically significant difference between swimmers and controls; systolic blood pressure fell in swimmers, and plasma homovanillic acid and beta-endorphin were unchanged across all seasonal samples in both groups.","claim_class":"observational","status":"source_derived_draft","evidence_grade":"ungraded","direction":"neutral","is_public":true,"mechanism_event_id":"00a83322-25f2-57b7-9aa6-7913a6409136","mechanism_event_label":"Across a whole season the swimmers changed no more than the people who stayed dry.","subject":{"id":"96a7dff2-caf4-51c1-93c4-c9ed08c05c9a","slug":"cold-water-immersion","display_name":"Cold water immersion","entity_type_key":"drug"},"object":{"id":"14452a0d-37f0-544d-8cc2-0b770a16b5d3","slug":"plasma-noradrenaline","display_name":"Plasma noradrenaline concentration","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"00a83322-25f2-57b7-9aa6-7913a6409136","stable_key":"b3c3f45a-50fb-5b79-98d7-5e5228df00db:cold-seasonal-catecholamine-fall-event","event_type":"observed_intervention","label":"Across a whole season the swimmers changed no more than the people who stayed dry.","description":"Mean plasma noradrenaline fell significantly from autumn to spring and more so in winter swimmers, but with no statistically significant difference between swimmers and controls; systolic blood pressure fell in swimmers, and plasma homovanillic acid and beta-endorphin were unchanged across all seasonal samples in both groups.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"9eda1162-1823-5c43-8e7d-4f2e4858c353","slug":"blood-pressure","display_name":"Arterial blood pressure","entity_type_key":"cellular_process"},"role":"measured_property","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"fef9ecc3-7c04-553c-a207-d91e38a2665a","slug":"serotonin","display_name":"Serotonin","entity_type_key":"small_molecule"},"role":"measured_metabolite","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"96a7dff2-caf4-51c1-93c4-c9ed08c05c9a","slug":"cold-water-immersion","display_name":"Cold water immersion","entity_type_key":"drug"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"14452a0d-37f0-544d-8cc2-0b770a16b5d3","slug":"plasma-noradrenaline","display_name":"Plasma noradrenaline concentration","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/cold-research/12546194.abstract.txt\", \"locator\": \"Indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"08c39cf0438d2f97c989e86721085415de696a3c7df99f5c2dc6529c40f7aeb2\", \"start_char\": 0, \"end_char\": 1785, \"text_sha256\": \"08c39cf0438d2f97c989e86721085415de696a3c7df99f5c2dc6529c40f7aeb2\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Follow-up of winter swimmers and non-swimmer controls sampled in autumn, winter and spring","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"One winter swimming season","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"A seasonal follow-up with a control group. Its negative conclusion is explicit: the changes seen in swimmers also occurred in controls.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake.","comparator":null,"unit":null,"notes":"","entity":{"slug":"cold-water-immersion","display_name":"Cold water immersion","entity_type_key":"drug"}},{"dimension":"organism","value_text":"Human","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Across a whole season the swimmers changed no more than the people who stayed dry.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[cold-p12546194] Plasma catecholamines, serotonin and their metabolites and beta-endorphin of winter swimmers during one winter. Possible correlations to psychological traits. (2002). https://pubmed.ncbi.nlm.nih.gov/12546194/ DOI: 10.3402/ijch.v61i4.17494","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Plasma hormones and blood pressure","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"0640a98c-d007-5f44-b7c7-0e444f8219b9","evidence_kind":"source_excerpt","locator":"Lines 663-674","start_line":663,"end_line":674,"excerpt":"### cold-seasonal-catecholamine-fall\nMean plasma noradrenaline fell significantly from autumn to spring and more so in winter swimmers, but with no statistically significant difference between swimmers and controls; systolic blood pressure fell in swimmers, and plasma homovanillic acid and beta-endorphin were unchanged across all seasonal samples in both groups.\nCondition category: normal\nnutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake.\nplain_language: Across a whole season the swimmers changed no more than the people who stayed dry.\norganism: Human\ntissue_or_cell_type: Plasma hormones and blood pressure\nexperimental_model: Follow-up of winter swimmers and non-swimmer controls sampled in autumn, winter and spring\nlimitations: A seasonal follow-up with a control group. Its negative conclusion is explicit: the changes seen in swimmers also occurred in controls.\nexposure: One winter swimming season\nevidence_span: {\"source_cache\": \"artifacts/cold-research/12546194.abstract.txt\", \"locator\": \"Indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"08c39cf0438d2f97c989e86721085415de696a3c7df99f5c2dc6529c40f7aeb2\", \"start_char\": 0, \"end_char\": 1785, \"text_sha256\": \"08c39cf0438d2f97c989e86721085415de696a3c7df99f5c2dc6529c40f7aeb2\"}\n[cold-p12546194] Plasma catecholamines, serotonin and their metabolites and beta-endorphin of winter swimmers during one winter. Possible correlations to psychological traits. (2002). https://pubmed.ncbi.nlm.nih.gov/12546194/ DOI: 10.3402/ijch.v61i4.17494","model_system":"Follow-up of winter swimmers and non-swimmer controls sampled in autumn, winter and spring","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [cold-p12546194] Plasma catecholamines, serotonin and their metabolites and beta-endorphin of winter swimmers during one winter. Possible correlations to psychological traits. (2002). https://pubmed.ncbi.nlm.nih.gov/12546194/ DOI: 10.3402/ijch.v61i4.17494","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"feeccadc-1392-573e-a0b5-0939ee5de6e2","stable_key":"import-b3c3f45a-50fb-5b79-98d7-5e5228df00db","title":"Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19)","document_type":"imported_text","citation_label":"AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text.","file_path":"","sha256":"557f074d372c49c502c34e648651aff7ebf2c8816305d2d2f08e338a7e96a5f0","revision_id":"ecc19e8d-40db-5b5d-b98e-0507f645976c","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[{"id":"f14b44fe-211d-50b5-a20c-f7874a8fd2bd","title":"Does repeated cold immersion change the catecholamine system, or not?","kind":"qualification","status":"open","why":"One study of winter swimmers during a one-hour immersion at 13 degrees C attributes more than a quarter of cold thermogenesis to adrenaline and finds an altered thermoregulatory threshold in adapted swimmers. A seasonal follow-up of winter swimmers and controls found plasma noradrenaline and adrenaline falling from autumn to spring with no significant difference between swimmers and controls, and concluded no clear effect of winter swimming as such. The two measure different things: the acute response during an immersion, and the resting baseline across a season. That difference may account for the disagreement, but neither study measured the other quantity, and it is not established here.","resolution":"Unresolved; needs review.","created_at":"2026-09-20 03:49:50","record_type":"conflict","display_label":"Recorded conflict","record_url":"/conflicts/f14b44fe-211d-50b5-a20c-f7874a8fd2bd","sides":[{"conflict_id":"f14b44fe-211d-50b5-a20c-f7874a8fd2bd","ordinal":0,"label":"A quarter of the heat may come from a hormone rather than from muscle shaking.","revision_id":"ecc19e8d-40db-5b5d-b98e-0507f645976c","start_line":624,"end_line":635,"quote":"### cold-catecholamine-thermogenesis-share\nHeat produced by the thermogenic action of adrenaline may represent more than a quarter of total cold thermogenesis, and in winter swimmers shivering was induced later during cooling, after 40 minutes, suggesting an important contribution of non-shivering thermogenesis to the early thermogenic response.\nCondition category: normal\nnutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake.\nplain_language: A quarter of the heat may come from a hormone rather than from muscle shaking.\norganism: Human\ntissue_or_cell_type: Whole body thermoregulation\nexperimental_model: Cold-adapted winter swimmers and controls during one hour of immersion at 13 degrees C\nlimitations: A comparison of adapted and unadapted people. The adrenaline contribution to thermogenesis is the authors’ estimate from their thermoregulation data, not a direct measurement of a hormone-driven heat fraction.\nexposure: One hour of cold water immersion at 13 degrees C\nevidence_span: {\"source_cache\": \"artifacts/cold-research/10825419.abstract.txt\", \"locator\": \"Indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"df5b07f571e51ae21572ac56aa97d1a9dffcd44fe8f5ead4c929086cbbd37e62\", \"start_char\": 0, \"end_char\": 2308, \"text_sha256\": \"df5b07f571e51ae21572ac56aa97d1a9dffcd44fe8f5ead4c929086cbbd37e62\"}\n[cold-p10825419] Thermoregulation in winter swimmers and physiological significance of human catecholamine thermogenesis. (2000). https://pubmed.ncbi.nlm.nih.gov/10825419/ DOI: 10.1111/j.1469-445x.2000.01909.x","source_key":"import-b3c3f45a-50fb-5b79-98d7-5e5228df00db","source_title":"Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19)","claim_ids":["693a1361-6b9d-5c4a-b602-952e491e20d2"]},{"conflict_id":"f14b44fe-211d-50b5-a20c-f7874a8fd2bd","ordinal":1,"label":"Across a whole season the swimmers changed no more than the people who stayed dry.","revision_id":"ecc19e8d-40db-5b5d-b98e-0507f645976c","start_line":663,"end_line":674,"quote":"### cold-seasonal-catecholamine-fall\nMean plasma noradrenaline fell significantly from autumn to spring and more so in winter swimmers, but with no statistically significant difference between swimmers and controls; systolic blood pressure fell in swimmers, and plasma homovanillic acid and beta-endorphin were unchanged across all seasonal samples in both groups.\nCondition category: normal\nnutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake.\nplain_language: Across a whole season the swimmers changed no more than the people who stayed dry.\norganism: Human\ntissue_or_cell_type: Plasma hormones and blood pressure\nexperimental_model: Follow-up of winter swimmers and non-swimmer controls sampled in autumn, winter and spring\nlimitations: A seasonal follow-up with a control group. Its negative conclusion is explicit: the changes seen in swimmers also occurred in controls.\nexposure: One winter swimming season\nevidence_span: {\"source_cache\": \"artifacts/cold-research/12546194.abstract.txt\", \"locator\": \"Indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"08c39cf0438d2f97c989e86721085415de696a3c7df99f5c2dc6529c40f7aeb2\", \"start_char\": 0, \"end_char\": 1785, \"text_sha256\": \"08c39cf0438d2f97c989e86721085415de696a3c7df99f5c2dc6529c40f7aeb2\"}\n[cold-p12546194] Plasma catecholamines, serotonin and their metabolites and beta-endorphin of winter swimmers during one winter. Possible correlations to psychological traits. 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