Exercise and physical activity in CKD, dialysis, and kidney transplant

It is often said that if exercise was a pill, it would be one of the most widely prescribed and cost-effective drugs ever invented. This is also true when looking at the management of chronic kidney disease (CKD), where exercise is a powerful, yet often underutilised tool.

The Irish Longitudinal Study on Ageing (TILDA) revealed in 2023 that the prevalence of CKD in Ireland is rising, with more than one-in-seven people over the age of 50 having the condition. However, 98 per cent of people do not know they have the condition. Patients with hypertension or diabetes are up to three times more likely to have CKD.¹

This study highlighted the importance going forward of action in primary and secondary care to raise awareness and to improve outcomes for people living with CKD in Ireland. It remains crucially important to emphasise the benefits of exercise and physical activity to our patients.

Globally, 28 per cent of adults are insufficiently active, and this sedentary behaviour is predicted to lead to 500 million new cases of non-communicable diseases before 2030.² Research indicates that those living with CKD are at particular risk of a sedentary lifestyle, and should be counselled regularly and encouraged to engage in exercise and physical activity as part of their regular treatment. However, this patient population are not routinely offered support as part of their care, with healthcare providers citing reasons such as lack of skills, time, and resources to access and implement exercise programmes.³

When managing many other chronic conditions, such as chronic obstructive pulmonary disease, or recovery following a cardiovascular event, exercise is a staple part of treatment, and there is access to pulmonary or cardiac rehabilitation services all over Ireland.

However, this is not always the case when looking at the management of CKD, despite the already well-established links between CKD and cardiovascular disease (CVD).⁴ With the role of the renal physiotherapist still in its infancy in Ireland, it is clear to see that there is a significant missed opportunity to improve physical, functional, psychological, and emotional outcomes for patients with high levels of frailty and CVD risk factors throughout all stages of CKD.

Physical activity recommendations

The terms physical activity and exercise are often used interchangeably in healthcare. Physical activity is defined as any bodily movement produced by skeletal muscles that results in energy expenditure, and encompasses everyday activities and hobbies such as gardening, housework, or playing a musical instrument. However, exercise is a subset of physical activity that is planned, structured, and repetitive, with the goal of improving or maintaining physical fitness.⁵

Some patients with CKD may be active, whether that be in work or day-to-day routines, but do not engage in formal exercise. While regular physical activity is important and helps to reduce the comorbidities associated with a sedentary lifestyle, in order to gain optimal benefits, patients should participate in regular structured exercise. This can range from an exercise class online or in person, to a daily walk.

The guidance has been consistent around exercise where there are no contraindications. As per the World Health Organisation and the UK Renal Association’s Clinical Practice Guidelines: ‘Exercise and Lifestyle in Chronic Kidney Disease’ published in 2022, the recommendations for people with CKD are the same as those for the general population – to aim for 150 minutes per week of moderate-intensity or 75 minutes per week of vigorous-intensity exercise.⁶ Exercise that aims to improve or maintain strength, balance, and flexibility is recommended to be completed at least twice per week.

Early management – exercise and lifestyle

In individuals with CKD, physical inactivity increases the risk of mortality, accelerates disease progression, and negatively impacts health-related quality-of-life. Management of CKD is a multifaceted approach, however, the general focus can often be on the pharmacological perspective of the disease, with not enough emphasis on lifestyle advice and intervention.

Holistic healthcare incorporates physical, mental, emotional, social, and spiritual components of health, and the management of CKD is no different. This requires a multidisciplinary team (MDT) approach for the best patient outcomes. Exercise will not have the greatest effect alone, and is much more influential when implemented alongside advice from other MDT members on dietary and behavioural modifications.

In pre-dialysis CKD, regular physical activity and exercise can lead to reductions in body weight, improvements in blood pressure, physical function and capacity, functional limitations, and health-related quality-of-life.⁶

There is a timeline of kidney disease progression, and at each of these stages there is one constant – the benefit of exercise and lifestyle advice. The recommended levels of activity might initially seem overwhelming for someone with a largely sedentary lifestyle, and people with CKD often fear exercise and potential injuries.

Early conversations and advice about lifestyle and exercise will promote best outcomes, and given the complex nature of CKD, guided, structured, and supervised exercise prescriptions from a trained professional are crucial to enhance patients’ knowledge, confidence, and awareness of safe exercise practices, fostering long-term engagement in new lifestyle changes.

Role of exercise in ESKD

For patients with end-stage kidney disease (ESKD), there are two options that may be considered beyond conservative management – dialysis or transplant.⁷ The National Renal Office (NRO) tracks the prevalence of patients receiving renal replacement therapy (RRT) in Ireland – either dialysis or transplant – and trends over the past 20 years show the demand for adult RRT has more than doubled.⁸

So, what does dialysis and ESKD mean in terms of exercise? Unfortunately, the majority of those receiving dialysis fall far below the threshold of the recommended levels of physical activity, and these patients experience higher levels of frailty, risk of falls, sarcopaenia, and hospital admissions than the general population.

There are a number of barriers to exercise for this cohort, including the challenges of regular hospital commutes to appointments and dialysis, fatigue, and multiple medical co-morbidities.⁹ It has also been shown that commencing dialysis is linked to a higher risk of functional impairment, frailty, mood disorders, and CVD.

Exercising while receiving dialysis, known as intradialytic exercise, may not be what many would consider a typical form of exercise, but there is an abundance of data supporting a multitude of benefits. Intradialytic exercise also has the potential to overcome many of the traditional barriers to exercise, such as time and commutes to appointments/sessions.

It is a safe, feasible, and effective way to reduce hospitalisations, improve quality-of-life, cardiovascular health, physical function, and muscular strength.^6,10

The Renal Association’s Clinical Practice Guidelines on Haemodialysis¹¹ clearly outline the recommendation for intradialytic exercise to be available in all dialysis units; however, these programmes are not yet routinely established throughout Ireland. Intradialytic exercise should include aerobic and resistance training for at least 30 minutes per haemodialysis session, and the best results are seen with programmes lasting longer than six months.

Aerobic exercise can be carried out on a specialised lower limb bike which can be used while a patient is resting in bed or a chair, and resistance training can be completed using resistance bands and/or handheld dumbbells or ankle weights.

It is recommended that all exercise is supervised by an appropriately trained member of staff, for example, a physiotherapist. If we consider the data from the NRO showing the significant number of patients on dialysis, it is important these patients have access to the resources, education, and research available about the benefit of exercises.

Similarly, for those completing peritoneal or haemodialysis at home, exercise is also shown to be extremely effective. Adequate levels of physical function are required to maintain strength and independence for people choosing to complete home-based therapy, and again, the addition of core exercises into a structured exercise programme for these patients is recommended and best led by an exercise professional.¹²

Exercise post-kidney transplant

For patients affected by ESKD, renal transplant can often represent a dramatic improvement in quality-of-life. However, the requirement for physical activity and exercise does not stop at kidney transplantation, as we now move to the maintenance stage of the exercise journey.

Kidney transplant recipients continue to face a heightened risk of cardiovascular, metabolic, and infectious diseases. Post-kidney transplant patients frequently report low physical activity, low energy, fatigue, poor exercise capacity, and a sedentary lifestyle.

To limit disease progression, enhance quality-of-life, and optimise physical function, a multidisciplinary renal rehabilitation approach – incorporating medical nutrition therapy and regular exercise – is recommended to support this population.⁶

Digital health interventions

Remote digital health interventions have been shown to be beneficial in improving physical activity and physical function across various chronic conditions.¹³ Although there are many health apps on the market, most are designed for the general population.

While they remain beneficial for those living with CKD, they are not specifically tailored to this population, and patients may not feel safe and assured that the exercises are suitable for them given the complexities of their condition.

Kidney Beam, developed by Dr Sharleen Greenwood, Consultant Physiotherapist, King’s College Hospital, London, UK, is a kidney-specific exercise and lifestyle management website/app designed to support, empower, and improve the lives of people living with CKD. Kidney Beam offers both live and on-demand exercise classes, education sessions, and programmes that people can complete from the comfort of their own homes.

Evidence from a randomised controlled trial in 2024 showed significant and clinically important improvements in health-related quality-of-life, and in the secondary outcome of physical function, in the Kidney Beam group, who completed a 12-week programme of twice weekly virtual exercise classes and education compared with usual care.¹⁴

There was also positive trends of improvement for secondary outcomes of symptom burden – social interaction, anxiety/depression, and patient activation – in the Kidney Beam intervention group. Given that access to a specialised renal physiotherapist is not widely available in Ireland and only available in the acute setting, digital health interventions may offer a way to help bridge this gap for patients in the interim.

Conclusion

Maintaining a healthy lifestyle remains a cornerstone in CKD management. However, despite the abundance of research highlighting the benefits of physical activity and exercise in those with CKD, exercise programmes are not always prioritised as part of standard care. Healthcare providers must advocate for and facilitate exercise programmes, while ensuring they are accessible and tailored to the needs of those with CKD in Ireland.

With the persistent increase in numbers of people with CKD, the role of the renal physiotherapist in Ireland is likely to develop further in the near future. It could prove significant in improving health outcomes and empowering patients to take an active role in managing their condition.

The promotion of regular exercise should be a vital component of CKD treatment strategies, aiming to reduce disease progression, enhance life quality, and ultimately provide a path to better health and wellbeing.