Negative effects of dialysis

One of the negative effects of long-term, repeated dialysis is that the treatment itself increases the risk of heart failure. A dialysis patient is connected to a dialysis machine, temporarily increasing the volume in which the blood circulates. This reduces blood flow to the heart, limiting its oxygen and nutrient supply. Over time, this can lead to reduced heart pumping capacity (myocardial stunning). Because the heart must work harder during every dialysis session, it can eventually result in heart enlargement and heart failure. At the same time, dialysis treatment is essential for these patients.

Exercise during dialysis, which activates circulation and the heart, can help counteract these negative effects. Additionally, movement during dialysis ensures a steady blood flow to vital organs.

For this reason, optimizing dialysis treatment to maintain the overall health of patients—including their heart health—is crucial in the long term. Exercise during dialysis plays an important role in this. This is why medical professionals and researchers advocate for making physical activity during dialysis a standard part of dialysis patient care worldwide (Morgan 2022, King 2022).

Research on exercise during dialysis

To demonstrate the benefits of cycling during dialysis (intradialytic cycling), two large randomized controlled trials were launched in 2016 and 2019, one of which involved multiple dialysis centers (DiaTT Trial: von Gersdorff 2022 en CYCLE-HD: Graham-Brown 2016). Both studies used cycling during dialysis as an intervention. Participants in the DiaTT trial cycled for twelve months, while participants in the CYCLE-HD trial cycled for six months. The research examined a wide range of effects on patients' health during and after dialysis, as well as long-term outcomes such as the previously mentioned effects on the heart and the cost-effectiveness of the exercise program.

Positive effects of exercise during dialysis

It was found that regular cycling during dialysis has multiple positive effects: for example, physical functioning in the non-cycling group declined, whereas in the cycling group, it remained the same as at the beginning of the study. Regarding quality of life, cycling only had a positive effect on questions about vitality, not on questions about other aspects of quality of life. Both groups were also the same in terms of the number of negative events (adverse events) that occurred during the study. Additionally, the median number of days a patient stayed in the hospital was shorter in the exercise group (two days) compared to the group that received standard care without cycling during dialysis (five days). Cycling during dialysis had no effect on dialysis-specific side effects or mortality. The authors concluded that twelve months of cycling during dialysis has positive effects on the long-term physical functioning of dialysis patients (Anding-Rost 2023 ClinicalTrials.gov: NCT03885102).

It was also found that six months of cycling during dialysis (CYCLE-HD) protected against long-term heart changes caused by repeated dialysis, which are associated with cardiovascular diseases (Graham-Brown 2021). That program was also cost-effective. In the CYCLE-HD trial, medical records were examined afterward for hospital utilization, primary care consultations, and the prescribing and use of medication by the study participants. This was examined during the trial and in the six months following. In the last six months, healthcare use and quality of life were also assessed. These costs were then compared to the costs of implementing the intervention. Cycling during dialysis was found to be cost-effective, and the authors concluded that the implementation of such programs should become a national priority (March 2021).

These larger randomized and controlled studies show that cycling during dialysis not only has positive short-term effects on the course of dialysis and the hours afterward but also benefits patients in the long term.

Summary of positive effects:

Maintenance of physical functioning:

• In the non-cycling group, physical functioning declined
• In the cycling group, it remained stable

Quality of life: cycling had a positive effect on vitality
Fewer hospitalizations (median number of days per admission):

• Cycling group: 2 days
• Non-cycling group: 5 days

Motivation to cycle

Nevertheless, it is sometimes difficult to motivate patients to cycle. Bike Labyrinth can help with this, as it is not only about exercising and being physically active but also about the joy of movement. Thanks to virtual cycling routes, exercising becomes an enjoyable experience and helps with relaxation. Be honest, what sounds more fun? “We’re going on a city trip to Rome” or “We’re cycling for 30 minutes?”.