{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,21]],"date-time":"2026-08-21T16:42:31Z","timestamp":1787330551640,"version":"build-2736575974"},"reference-count":25,"publisher":"JMIR Publications Inc.","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JMIR Res Protoc"],"abstract":"Abstract<\/jats:title>\n \n Background<\/jats:title>\n \n Cardiovascular disease (CVD) prevention is limited by the major challenge of low long-term adherence to effective lifestyle regimens. Arterial stiffness (measured by carotid-femoral pulse wave velocity [cfPWV]) and maximal cardiorespiratory fitness (measured by VO\n 2<\/jats:sub>\n max) are modifiable risk factors for CVD but require sustained lifestyle change. Wearable technology provides continuous measurement and offers a scalable platform to deliver health interventions. A combination of continuous monitoring with a wearable device and an AI-based coach personalized to individual data and preferences could be a powerful, low-barrier tool for achieving sustainable cardiovascular health benefits by directly addressing the adherence challenge.\n <\/jats:p>\n <\/jats:sec>\n \n Objective<\/jats:title>\n \n We will study the comparative effectiveness of a wearable and an interactive app-based AI coaching intervention promoting moderate exercise in improving gold-standard cfPWV and VO\n 2<\/jats:sub>\n max. This will be compared to a supervised high-intensity interval training (HIIT) group (benchmark with known benefits for VO\n 2<\/jats:sub>\n max) and a control group using only the Oura Ring (passive monitoring). We will also conduct a detailed process evaluation (structured interviews) to study the feasibility and experience of interacting with the AI coach.\n <\/jats:p>\n <\/jats:sec>\n \n Methods<\/jats:title>\n \n This randomized controlled trial will recruit 165 eligible sedentary participants aged 30 to 65 years. The co-primary outcomes, cfPWV and VO\n 2<\/jats:sub>\n max, are measured at baseline and will be repeated after 12 weeks. Participants are equally randomized into 3 groups: an AI-based coaching group (steady-state exercise), an HIIT group (supervised exercise), and a control group (usual low activity). The AI-based coaching group receives personalized guidance using large language model technology. All participants wear the Oura Ring and are blinded to the cardiovascular health metrics provided by the ring.\n <\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n The recruitment for the study began in October 2024 and will end when 165 men and women have been recruited. Data collection for the study is scheduled to conclude in early 2026. Data management is ongoing.<\/jats:p>\n <\/jats:sec>\n \n Conclusions<\/jats:title>\n \n This study will evaluate whether a potentially highly scalable, AI-based coaching intervention can achieve comparable gains in cardiovascular structural health (cfPWV) and functional capacity VO\n 2<\/jats:sub>\n max relative to a resource-intensive supervised HIIT benchmark. The findings will provide essential evidence on the use of digital health tools to promote sustainable exercise adherence.\n <\/jats:p>\n <\/jats:sec>","DOI":"10.2196\/98213","type":"journal-article","created":{"date-parts":[[2026,8,21]],"date-time":"2026-08-21T16:11:36Z","timestamp":1787328696000},"page":"e98213-e98213","source":"Crossref","is-referenced-by-count":0,"title":["The Effects of AI-Guided Exercise and a Smart Ring on Arterial Stiffness: Protocol for a Randomized Controlled Trial"],"prefix":"10.2196","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4585-7329","authenticated-orcid":false,"given":"Heikki","family":"Pentik\u00e4inen","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7344-1630","authenticated-orcid":false,"given":"Sofia","family":"Str\u00f6mmer","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0009-5639-7899","authenticated-orcid":false,"given":"Drake","family":"Caraker","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0001-2953-0596","authenticated-orcid":false,"given":"Julia","family":"Kosonen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-7736-4600","authenticated-orcid":false,"given":"Aleksi","family":"Rantanen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0003-8866-7079","authenticated-orcid":false,"given":"Saila","family":"Hiltunen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7934-3465","authenticated-orcid":false,"given":"Pirjo","family":"Komulainen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0241-1957","authenticated-orcid":false,"given":"Heidi","family":"Simil\u00e4","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0057-5977","authenticated-orcid":false,"given":"Massimiliano","family":"de Zambotti","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6871-8153","authenticated-orcid":false,"given":"Kai","family":"Savonen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0919-7204","authenticated-orcid":false,"given":"Pauli","family":"Ohukainen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1010","published-online":{"date-parts":[[2026,8,21]]},"reference":[{"issue":"22","key":"R1","doi-asserted-by":"publisher","first-page":"2167","DOI":"10.1016\/j.jacc.2025.08.015","article-title":"Global, regional, and national burden of cardiovascular diseases and risk factors in 204 countries and territories, 1990-2023","volume":"86","author":"Stark","journal-title":"J Am Coll Cardiol"},{"issue":"24","key":"R2","doi-asserted-by":"publisher","first-page":"e653","DOI":"10.1161\/CIR.0000000000000461","article-title":"Importance of assessing cardiorespiratory fitness in clinical practice: a case for fitness as a clinical vital sign: a scientific statement from the American Heart Association","volume":"134","author":"Ross","journal-title":"Circulation"},{"issue":"21","key":"R3","doi-asserted-by":"publisher","first-page":"2588","DOI":"10.1093\/eurheartj\/ehl254","article-title":"Expert consensus document on arterial stiffness: methodological issues and clinical applications","volume":"27","author":"Laurent","journal-title":"Eur Heart J"},{"issue":"1","key":"R4","doi-asserted-by":"publisher","first-page":"3","DOI":"10.1161\/HYPERTENSIONAHA.109.129114","article-title":"Vascular aging: a tale of EVA and ADAM in cardiovascular risk assessment and prevention","volume":"54","author":"Nilsson","journal-title":"Hypertension"},{"issue":"1","key":"R5","doi-asserted-by":"publisher","first-page":"127","DOI":"10.1161\/01.atv.18.1.127","article-title":"Absence of age-related increase in central arterial stiffness in physically active women","volume":"18","author":"Tanaka","journal-title":"Arterioscler Thromb Vasc Biol"},{"issue":"5","key":"R6","doi-asserted-by":"publisher","first-page":"478","DOI":"10.1111\/sms.12495","article-title":"The effects of aerobic endurance exercise on pulse wave velocity and intima media thickness in adults: a systematic review and meta-analysis","volume":"26","author":"Huang","journal-title":"Scand J Med Sci Sports"},{"issue":"18","key":"R7","doi-asserted-by":"publisher","first-page":"e972","DOI":"10.1161\/CIR.0000000000001314","article-title":"Role of technology in promoting heart healthy behavior change to increase equity in optimal cardiovascular health: a scientific statement from the American Heart Association","volume":"151","author":"Powell-Wiley","journal-title":"Circulation"},{"issue":"1","key":"R8","doi-asserted-by":"publisher","DOI":"10.1038\/s41746-023-00856-1","article-title":"Systematic review and meta-analysis of the effectiveness of chatbots on lifestyle behaviours","volume":"6","author":"Singh","journal-title":"NPJ Digit Med"},{"issue":"2","key":"R9","doi-asserted-by":"publisher","first-page":"100294","DOI":"10.1016\/j.jjimei.2024.100294","article-title":"Overview of the future impact of wearables and artificial intelligence in healthcare workflows and technology","volume":"4","author":"LaBoone","journal-title":"International Journal of Information Management Data Insights"},{"key":"R10","unstructured":"US Department of Health and Human Services. Physical Activity Guidelines for Americans. 2nd edition ed. US Department of Health and Human Services; 2018. URL: https:\/\/odphp.health.gov\/sites\/default\/files\/2019-09\/Physical_Activity_Guidelines_2nd_edition.pdf [Accessed 05-08-2026]"},{"issue":"1","key":"R11","doi-asserted-by":"publisher","first-page":"183","DOI":"10.1161\/HYPERTENSIONAHA.123.21618","article-title":"2024 Recommendations for validation of noninvasive arterial pulse wave velocity measurement devices","volume":"81","author":"Spronck","journal-title":"Hypertension"},{"key":"R12","doi-asserted-by":"publisher","DOI":"10.3389\/fcvm.2022.993971","article-title":"The effects of experimental, meteorological, and physiological factors on short-term repeated pulse wave velocity measurements, and measurement difficulties: a randomized crossover study with two devices","volume":"9","author":"Podrug","journal-title":"Front Cardiovasc Med"},{"issue":"8","key":"R13","doi-asserted-by":"publisher","first-page":"1381","DOI":"10.1249\/01.MSS.0000078924.61453.FB","article-title":"International physical activity questionnaire: 12-country reliability and validity","volume":"35","author":"Craig","journal-title":"Med Sci Sports Exerc"},{"issue":"201","key":"R14","first-page":"1","volume":"58","author":"Tornvall","journal-title":"Acta Physiol Scand"},{"issue":"1","key":"R15","doi-asserted-by":"publisher","first-page":"81","DOI":"10.1007\/s12160-013-9486-6","article-title":"The Behavior Change Technique Taxonomy (v1) of 93 hierarchically clustered techniques: building an international consensus for the reporting of behavior change interventions","volume":"46","author":"Michie","journal-title":"ann behav med"},{"key":"R16","unstructured":"Rosner B . Hypothesis testing: two-sample inference. In: Fundamentals of Biostatistics. 7th ed. Brooks\/Cole; 302-303. URL: https:\/\/studylib.net\/doc\/27109472\/fundamentals-of-biostatistics--7th-edition-?p=7 [Accessed 06-08-2026]"},{"issue":"12","key":"R17","doi-asserted-by":"publisher","first-page":"1234","DOI":"10.1016\/j.jclinepi.2007.02.006","article-title":"A simple sample size formula for analysis of covariance in randomized clinical trials","volume":"60","author":"Borm","journal-title":"J Clin Epidemiol"},{"issue":"2","key":"R18","doi-asserted-by":"publisher","first-page":"189","DOI":"10.1080\/19345747.2011.618213","article-title":"Why we (usually) don\u2019t have to worry about multiple comparisons","volume":"5","author":"Gelman","journal-title":"J Res Educ Eff"},{"issue":"7262","key":"R19","doi-asserted-by":"publisher","first-page":"694","DOI":"10.1136\/bmj.321.7262.694","article-title":"Framework for design and evaluation of complex interventions to improve health","volume":"321","author":"Campbell","journal-title":"BMJ"},{"key":"R20","doi-asserted-by":"publisher","DOI":"10.1136\/bmj.n2061","article-title":"A new framework for developing and evaluating complex interventions: update of Medical Research Council guidance","volume":"374","author":"Skivington","journal-title":"BMJ"},{"key":"R21","doi-asserted-by":"publisher","DOI":"10.46743\/2160-3715\/2023.6406","article-title":"\u0397ow to use artificial intelligence (AI) as a resource, methodological and analysis tool in qualitative research?","author":"Christou","journal-title":"TQR"},{"key":"R22","doi-asserted-by":"publisher","DOI":"10.46743\/2160-3715\/2024.7046","article-title":"Thematic analysis through artificial intelligence (AI)","author":"Christou","journal-title":"TQR"},{"key":"R23","doi-asserted-by":"publisher","DOI":"10.1016\/j.metip.2025.100183","article-title":"Using large language models for narrative analysis: a novel application of generative AI","volume":"12","author":"Jenner","journal-title":"Methods in Psychology"},{"key":"R24","doi-asserted-by":"publisher","DOI":"10.3389\/fcvm.2022.960096","article-title":"The effect of aerobic exercise on pulse wave velocity in middle-aged and elderly people: a systematic review and meta-analysis of randomized controlled trials","volume":"9","author":"Li","journal-title":"Front Cardiovasc Med"},{"issue":"2","key":"R25","doi-asserted-by":"publisher","DOI":"10.1136\/openhrt-2023-002384","article-title":"Effect of aerobic exercise training on pulse wave velocity in adults with and without long-term conditions: a systematic review and meta-analysis","volume":"10","author":"Bakali","journal-title":"Open Heart"}],"container-title":["JMIR Research Protocols"],"original-title":[],"language":"en","deposited":{"date-parts":[[2026,8,21]],"date-time":"2026-08-21T16:11:41Z","timestamp":1787328701000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.researchprotocols.org\/2026\/1\/e98213"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,21]]},"references-count":25,"URL":"https:\/\/doi.org\/10.2196\/98213","relation":{},"ISSN":["1929-0748"],"issn-type":[{"value":"1929-0748","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,21]]},"article-number":"v15i22e98213"}}