Background: Aquatic exercise has long been a popular activity among members of the Norwegian Rheumatism Association (NRF), although its potential effects remain unclear. Individuals with rheumatic diseases face a higher risk of cardiovascular disease [1]. Patients with rheumatoid arthritis and other inflammatory joint disease are twice as likely to develop heart disease [1]. The 2019 ESpA study showed that high-intensity exercise reduces disease activity, fatigue, stiffness, pain, and inflammation. Recent research highlights that high-intensity endurance training can improve cardiorespiratory fitness and reduce cardiovascular risk, even in individuals with rheumatic conditions. Despite these benefits, there are limited research on high-intensity training in warm water for rheumatic conditions. NRF collaborated with leading researchers to investigate this question. Positive feedback from our members on high-intensity exercise led to the development of a pilot project aimed to examine its potential effects on cardiovascular health.

Objectives: The overall purpose was to implement a high-intensity training project to assess the feasibility of this type of exercise in warm water for people with inflammatory rheumatic disease. An additional objective was to evaluate whether volunteer instructors could independently lead the training sessions.

Methods: A six-week high-intensity interval training program in warm water designed specifically for individuals with musculoskeletal disorders and rheumatic diseases. Members from across Norway expressed their interest to participate in the project. Phase 1 involved recruiting ten participants, finalizing the training program, conducting tests, and adjusting due to Covid-19. The program included a warm-up, cardio intervals (four 4-minute sessions), and strength training based on the Tabata method (tabataprotocol.com). Phase 2 included physical tests, self-reported questionnaires and heart rate monitoring using Garmin Swim 2. Participants performed high-intensity intervals with four exercises, collecting RPE (rating of perceived exertion) and heart rate. Phase 3 involved gathering feedback and adjusting the program. The training program was modified, and developed three variants of 30, 45, and 60 minutes. A framework for educating volunteer instructors was designed by the project group.

Results: A total of eight participants was recruited, however some of the tests lacked complete responses due to participants forgetting to answer certain questions. Despite this, interesting key findings emerged from the self-reported CERG test (Cardiac exercise research group test) and other measurements. The results indicated an increase in maximum oxygen uptake among the participants. Additionally, seven out of eight participants (87,5%) showed improvement in their walk test scores post-intervention. Notably, five participants (62,5%) had a lower heart rate after the walk test, which suggests improvements in cardiovascular fitness. Participants also experienced a reduction in their cardiorespiratory biological age, highlighting positive changes in their overall fitness and health. Furthermore, self-reported physical activity levels increased across all participants, suggesting greater engagement in physical activity after the intervention. In terms of physical function in daily living, seven out of eight participants reported improvements, indicating that the training positively impacted their ability to perform everyday activities. As a bonus, the volunteer instructor received top ratings from all participants, reflecting high satisfaction with the quality of the instruction.

Conclusion: A six weeks of high-intensity interval training in warm water can lead to improvements in functional capacity, physical walking test performance, increased motivation, and enhanced results in self-reported physical fitness, improved VO2 max and reduced barriers to physical activity. The project group developed a specialized education program for volunteer instructors to lead such sessions. The exercise holds strong transferability, as the volunteer instructor highly influenced the project, exercise program design and the execution of exercise. Furthermore, the project served as an excellent pilot for research, whereas Oslo MET University undergoing the exercise program in a RCT study.

REFERENCES: [1] Agca, R., Heslinga, C., Rollefstad, S., Heslinga, M., McInnes, I., Peters, M.,... et.al. (2017). EULAR recommendations for cardiovascular disease risk management in patients with rheumatoid arthritis and other forms of inflammatory joint disorders: 2015/2016 update. BMJ, 76 , ss. 17-28.

[2] Sveaas S. H.,... et.al. (2020). High intensity exercise for 3 months reduces disease activity in axial Spondylarthritis (axSpA): a multicenter randomized trial of one hundred patients. British Journal of Sports Medicine 2020; 54:292-297.

Acknowledgements: NIL.

Disclosure of Interests: None declared.

© The Authors 2025. This abstract is an open access article published in Annals of Rheumatic Diseases under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ). Neither EULAR nor the publisher make any representation as to the accuracy of the content. The authors are solely responsible for the content in their abstract including accuracy of the facts, statements, results, conclusion, citing resources etc.