Enrollment was stopped due to covid-19 pandemic. An alternate study was initiated under an alternate IRB and clinical trial registration which allowed home exercise instead of in-center exercise after a prolonged pause in enrollment.

Frailty is a condition characterized by slowness, weakness, low physical activity, wasting, and exhaustion. Frailty increases the risk for adverse outcomes following transplant such as increased length of stay in the hospital, mortality, or graft function. No interventions for frailty are known for patients with renal disease, but exercise programs like pulmonary rehabilitation have been effective in improving frailty in patients with other diseases, such as lung disease. The goal of this study is to test whether exercise will also improve frailty among patients who are waiting for a kidney transplant and who are considered frail or pre-frail.

RECRUITMENT: This study will be conducted at Mayo Clinic in Rochester, MN. Patients over 18 who have chronic kidney disease will be approached for recruitment. Interested patients will go through the informed consent process and, if frailty testing was not completed within the two weeks prior to consent, patients will complete frailty testing. If patients are considered frail or pre-frail, they will be enrolled in the study.

FRAILTY TESTING: Participants will complete the FP, Short Physical Performance Battery (SPPB) and other frailty testing at the beginning of the study, 4 weeks after beginning the intervention, and 8 weeks after beginning the intervention. Frailty testing will include a hand grip strength test, a gait speed test over 15 feet, repeated chair stands, balance testing, and a body composition scan. Participants will also be asked to wear an activity monitor for 5-7 days at each testing point and to complete a set of questionnaires. Height, weight, BMI, skeletal muscle mass, percent body fat, and segmental lean mass will be recorded. Participants with a pacemaker, an implantable cardioverter-defibrillator (ICD), or an automated ICD (AICD) will not be able to complete. At enrollment, participants 55 and older will undergo a submaximal exercise test to rule out significant undiagnosed cardiopulmonary disease (standard entrance criteria for pulmonary rehabilitation).

INTERVENTION: Participants will be asked to complete 2 1-hour exercise sessions per week for 8 weeks (16 total sessions) under the supervision of a licensed respiratory therapist in Rochester, MN on non-dialysis days unless the participant is on daily or near-daily dialysis (e.g. home hemodialysis or peritoneal dialysis). . The exercise sessions will be based on pulmonary rehabilitation and will follow guidelines established by the American Thoracic Society. Exercise sessions will include endurance (treadmill or cycle ergometer), strength, and flexibility training and will be tailored to individual participants.

Inclusion Criteria:

• Aged 18 years or older
• Consenting to research
• CKD (stages 1-5)
• An SPPB score ≤10 or considered frail or pre-frail by FP

Exclusion Criteria:

• Younger than 18 years
• Patients listed for heart or lung transplants
• Terminal illness with a prognosis of less than 6 months
• Significant comorbidities that limit rehabilitation potential including pulmonary disease requiring continuous oxygen supplementation, active angina, critical aortic sclerosis, decompensated heart failure, or known ventricular arrhythmia.
• Kidney transplant candidates without cardiac clearance for transplant
• An SPPB score >10 or not considered frail or pre-frail by FP
• Non-English speaker without availability of adequate interpreter services (safety concern)
• Failure to pass submaximal exercise test