Design: Systematic review and meta-analysis of 14 RCTs
Population: 934 adults on maintenance haemodialysis
Primary outcome: Cardiac, vascular and cardiorespiratory parameters
Effect: LVEF +2.21% (0.28–4.15); PWV −1.36 m/s; peak VO2 +2.76 mL/kg/min

This meta-analysis pooled 14 randomised trials with 934 adults on maintenance haemodialysis, comparing structured intradialytic exercise with usual care. It was published in BMJ Open in September.

Exercise improved LVEF by 2.2 percentage points (95% CI 0.3 to 4.2), reduced pulse wave velocity by 1.36 m/s (0.13 to 2.58) and diastolic pressure by 4.5 mm Hg, and increased peak oxygen uptake by 2.8 mL/kg/min. Left ventricular mass and systolic pressure did not change significantly. Certainty was moderate to low, with some risk-of-bias concerns and high heterogeneity for peak VO2.

Intradialytic cycling costs little, uses time patients already spend in the unit and appears safe. The gains are modest and on surrogate measures, but for a population with very poor fitness they are worth having.

Offer in-chair cycling during the first two hours of dialysis.
Start at low resistance and build over weeks.
Avoid exercise late in a session when hypotension is more likely.
Pair with nutritional review to support muscle gain.

Why it matters

It turns dialysis time into exercise time for a population with very low fitness.

The statistics, in plain English

The effects are small and several intervals nearly touch zero. High heterogeneity for peak VO2 (I² 90%) means the trials disagreed widely. These are surrogate measures; the analysis does not show fewer cardiovascular events.