Three-week exercise and protein intake immediately after exercise increases the 6-min walking distance with simultaneously improved plasma volume in patients with chronic cerebrovascular disease: a preliminary prospective study

BACKGROUND: Blood volume (BV) is a critical factor for physical endurance in chronic stroke patients, while hypervolemia can worsen hypertension in these patients. This prospective study assessed whether rehabilitation combined with protein supplementation immediately after each exercise for 3 weeks would improve plasma volume (PV) and BV as well as physical endurance without worsening hypertension. METHODS: Ambulatory patients with chronic cerebrovascular disease who received a 3-week rehabilitation program with high protein jelly (intervention group [PG]; n = 8; 10-g protein) or protein-free jelly (control group [CG]; n = 8) consumed within 30 min after each exercise. PV and BV were assessed while measuring the 6-min walking distance (6MWD), peak oxygen consumption (VO(2peak)), strength of knee extension, and resting blood pressure before and after the intervention. Two-way ANOVA was used to determine whether there was an interaction of time × group. The difference between before and after intervention or between the groups by post-hoc test (Tukey’s test) at the level of P < 0.05. RESULTS: The 6MWD increased only in the PG (P = 0.001; an interaction of Group and Time, P = 0.037). PV and BV increased only in the PG (P < 0.05). VO(2peak) and strength of knee extension in the paralysed limb increased in both groups (P < 0.05). The resting blood pressure did not worsen after the intervention. CONCLUSIONS: In chronic post-stroke patients, 3-week rehabilitation combined with protein intake immediately after exercise increased 6MWD simultaneously with increased PV and BV, but it did not increase resting blood pressure. The present regimen is acceptable and effective for ambulatory patients with chronic cerebrovascular disease. Name of the registry Examining effects of protein supplementation on functional improvement during rehabilitation intervention in chronic stroke patients Trial registration number UMIN000028009; date of registration: 30/06/2017. This study was registered prospectively. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13102-022-00429-x.