Flywheel Exercise for CKD

Among Veterans, the prevalence of chronic kidney disease (CKD) is reported to be as high as 47.3% and a third higher than the general population. Muscle wasting and dysfunction have been identified as primary consequences of CKD. Disease-induced reductions in lean tissue adversely affect muscle fatigability. Consequently, muscle fatigability may serve as a potential limiting factor that contributes to activity limitations. However, there is a lack of evidence informing our understanding of muscle fatigability in patients with CKD. Dialysis treatment is a major factor contributing to the high financial costs of CKD care. Thus, in addition to potential health and quality of life benefits, treatments capable of maintaining kidney function or delaying the onset of dialysis treatment would provide substantial socio-economic benefit. Both lean body mass and muscle fatigability may be improved through strength training. Eccentric-overload (i.e. muscle lengthening) progressive resistance exercise (PRE) has been shown to be safe and effective for a variety of chronic conditions. Eccentric PRE using portable flywheel technology may provide a clinically viable treatment option to combat muscle impairments in CKD given the cost effectiveness and minimal space requirements for this mode of exercise. The purpose of this study is to assess feasibility of the eccentric-overload PRE regimen for Veterans with CKD stage 3 & 4 predialysis using a prospective single-arm pre-test post-test intervention design. The primary aim of the project is to determine the effects of eccentric-overload PRE on muscle fatigability in Veterans with CKD Stages 3 & 4 predialysis. Feasibility of the regimen will be determined by the time needed to complete the 4-exercise regimen and the perceived exertion levels reported by the study participants.

12 weeks of 2x per week of the following eccentric exercises: squat, shoulder press, row, and bicep curl.

Knee extensor muscle fatigability will be assessed using a protocol consisting of 30 repetitions or to failure, whichever comes first, at their maximum strength

Unilateral peak knee extension/flexion isokinetic force (at 180º/s and 60º/s) will be obtained across five continuous repetitions using a load cell

This composite score is made up of measures of balance, gait speed (15 ft), and timed chair stands (x5).

This test will begin the test with the subject fully sitting in a chair with arm rests, with the upright mobility portion of the test focused on an easily visible marked target 3 meters away from the chair

Sonographic estimates of LBM (aggregate muscle thickness, cm) will serve as a proxy measure for muscle tissue composition in this study

Sonographic estimates of myosteatosis (grayscale, or GSL, values, 0-255) will serve as a proxy measure for muscle tissue composition in this study

This measure will be obtained with a hand grip dynamometer using the mean value of 3 trials under standardized conditions.

general physical functioning questionnaire; each of eight sections range 0-100 with higher values indicating less disability. The eight sections include vitality, physical functioning, bodily pain, general health perceptions, physical role functioning, emotional role functioning, social role functioning, and mental health.

Inclusion Criteria: ambulatory patients (with or without a gait aid) CKD stage 3 or 4 patients receiving care at the DC VAMC Renal Service the ability to speak and read English orientation to person, place, and time Exclusion Criteria: unable to speak English acute renal failure pregnant unable to follow study instructions any uncontrolled cardiovascular or musculoskeletal problems that would make participation in this study unsafe