#596 The Borg Scale—efficient and safe for exercise prescription in self-administered balance and strength exercise in patients with CKD

Abstract Background and Aims With the continued rise in chronic kidney disease (CKD), there is a critical need for sustainable, home-based exercise interventions. While supervised, centre-based exercise improves physical performance in CKD patients, unsupervised, self-administered exercise poses challenges in ensuring adherence, safety, and efficacy. This study investigates the Borg Rating of Perceived Exertion (RPE) scale, a subjective measure of exertion, as a method for prescribing and monitoring the intensity of balance and strength exercise in non-dialysis dependent CKD patients. The aims of this study were: Method This sub study of the RENEXC-trial included 148 patients with CKD stages 3-5, with a mean age of 66 ± 14 years and mean measured GFR of 22 ± 8 ml/min/1.73 m2. Patients were prescribed 90 minutes/week of balance or strength exercise at a Borg RPE of 13-17 (corresponding to an exercise intensity of somewhat hard to very hard), along with 60 minutes/week of endurance exercise. Exercise programs were individually prescribed by a physiotherapist according to randomization and each patient's baseline performance and were performed at home or in a gym according to the patient's preference. Duration and RPE of the performed exercise were reported in an exercise diary. Progress was monitored by the physiotherapist through phone contact, every week for the first three months of the study and every other week for the rest of the study year. The continuous follow up provided motivation and enabled adjustments of the exercise program to maintain the goal RPE, adapt intensity and the weekly duration of exercise. Outcome measures included the Berg Balance Scale (BBS) and Functional Reach Test (FRT), the 30-second sit-to-stand test (30STS) and isometric quadriceps strength (IQS). Balance and strength measures were evaluated at baseline and after 12 months of exercise. Previous publications of the RENEXC-trial showed no difference between patients who performed balance exercise and patients who performed strength exercise; therefore, this sub-study analysed all included patients as one group. Results Of 148 participants, 112 completed the study. At 12 months, 79% reported performed exercise, with 86% of these patients adhering to the prescribed intensity. The median (25th-75th percentile) exercise intensity was a RPE of 14 (13-15) on the Borg scale, and the median (min-max) exercise duration was 48 (0-241) minutes/week. Only 18% of the patients reached the 90-minute/week target. No exercise-related incidents were reported. Significant improvements were noted in BBS (p = 0.0464), FRT (p = 0.009), 30STS (p = 0.047), and IQS (right/left p = 0.022 / p = 0.049). Conclusion The Borg RPE scale is an effective and safe method for prescribing and monitoring self-administered balance and strength exercise in patients with CKD. Using the Borg scale for prescribing and monitoring exercise intensity during balance and strength exercise resulted in a good level of adherence to the 12-months exercise program and the prescribed exercise intensity. As no exercise related incidents were reported, we conclude that the self-administered exercise was safe to perform. Significant improvements in balance and strength were observed with a moderate to high exercise intensity prescription within a wide range of performed weekly duration of exercise, suggesting the Borg scale's value in exercise prescription in both well- and deconditioned patients with CKD. These findings show that the integration of the Borg scale into routine exercise prescription in people with CKD can promote patient autonomy and efficient resource utilization in healthcare.