Acute Haemodynamic and Perceptual Responses to Graded Intradialytic Exercise in Patients on Maintenance Haemodialysis: A Randomised Crossover Trial.

Acute responses to graded intradialytic exercise in people receiving haemodialysis remain incompletely characterised. To examine acute haemodynamic and perceptual responses to graded intradialytic resistance exercise compared with a non-exercise control condition. Randomised crossover trial. Forty-eight clinically stable adults receiving maintenance haemodialysis. Participants completed seated control and graded lower-limb resistance exercise targeting Borg category-ratio 10 ratings of 3, 5 and 7. Systolic and diastolic blood pressure, mean arterial pressure, heart rate, peripheral oxygen saturation, rating of perceived exertion and acute fatigue were measured before, immediately after and 30 min after each condition. Responses increased progressively with perceived intensity. Compared with control, higher perceived intensity increased systolic blood pressure by 14.9 mmHg (95% confidence interval = 12.7-17.0), diastolic blood pressure by 8.4 mmHg (6.8-10.0), mean arterial pressure by 10.6 mmHg (9.2-12.0) and heart rate by 15.5 beats per minute (12.9-18.1). Rating of perceived exertion increased by 6.7 points (95% confidence interval = 6.3-7.1). Mean peripheral oxygen saturation remained between 95.1% and 97.5%, with no value below 90%. Recorded symptoms occurred in 13 out of 48 higher perceived-intensity sessions; no serious adverse events occurred. Graded, rating-guided intradialytic resistance exercise produced clear acute dose-response haemodynamic and perceptual changes. These findings support supervised individualisation of acute exercise dose but do not establish long-term safety or superiority of higher perceived-intensity training. Pan African Clinical Trial Registry: PACTR202606476360900.