USING THE BORG SCALE FOR EXERCISE PRESCRIPTION AND FOR MONITORING SELF-ADMINISTERED AEROBIC ENDURANCE EXERCISE IS SAFE AND EFFECTIVE FOR PATIENTS WITH CKD

Abstract BACKGROUND AND AIMS Decline in physical function starts relatively early in the course of CKD and has an impact on activities in daily life, such as walking capacity. Several studies with supervised centre-based exercise training as well as studies with self-administered home-based exercise have shown improvement in walking capacity. However, monitoring intensity and safety is important when exercise is self-administrated. There are to our knowledge no studies evaluating the Borg RPE scale as a tool to prescribe exercise intensity and as an instrument for self-monitoring exercise training in patients with CKD. The aims of this study were to examine the adherence, performance, and safety of self-administered aerobic endurance exercise when exercise intensity was prescribed and self-monitored with the Borg rating of perceived exertion (RPE) scale in non-dialysis dependent patients with CKD stages 3–5, and the relationship between performed exercise and change in walking distance. METHOD In this sub-study of the RENEXC trial 147 patients (97 men, 50 women), irrespective of age and comorbidities, were included. Mean age was 66 ± 14 years and the mean measured GFR 22 ± 8 mL/min/1.73 m2. Twelve months of aerobic endurance exercise (60 min/week) was combined with either balance or strength exercises (90 min/week). All exercise was individually prescribed by a research physiotherapist, based on each patient's baseline tests. The aerobic endurance exercise was prescribed to have a level of intensity between 13 (somewhat strenuous) to 15 (strenuous) using the Borg RPE scale. Exercise was self-monitored and recorded in a training diary. Follow up was performed by the physiotherapist through phone contact. The 6-min walk test was measured at baseline and after 4, 8 and 12 months of exercise. RESULTS Hundred patients completed the study. Our training program had an excellent level of adherence, at 12 months 80% of the patients reported performed exercise and 74% performed exercise within the prescribed intensity. The mean intensity of the aerobic endurance exercise was rated at 13 ± 1 on the Borg RPE scale. Median duration of aerobic endurance exercise was 56 (33–109) minutes/week. However, there was a wide range of weekly duration where patients with a low walking distance at baseline performed less minutes of exercise/week (P = 0.039). Irrespective of weekly duration the patients were able to perform exercise within the prescribed interval of RPE 13–15. No exercise related incidents were reported. Walking distance improved significantly by mean 30 ± 56 meters (P < 0.001). There was no correlation between weekly duration of exercise and change in walking distance, indicating that deconditioned patients with a short baseline walking distance can increase walking capacity when performing a shorter weekly duration of somewhat strenuous to strenuous exercise, whereas patients with a higher baseline walking distance must perform a longer duration of exercise to increase walking capacity. CONCLUSION The Borg RPE scale is a useful, acceptable, simple and safe method for prescribing and monitoring intensity of self-administered aerobic endurance exercise in patients with CKD. A RPE of somewhat strenuous to strenuous improved walking capacity in deconditioned patients with CKD, within a wide range of weekly duration of exercise.