Stroke is a leading cause of disability and the second leading cause of death worldwide. Most strokes are ischemic, caused by acute arterial occlusion. Post-stroke treatment focuses on secondary prevention and rehabilitation, but few treatments address functional recovery. Creatine, a supplement known for improving physical performance, may aid in the recovery of stroke patients, reducing sarcopenia and improving strength among other effects. This pilot study will investigate the effectiveness of creatine supplementation in enhancing physical and functional recovery in ischemic stroke patients. The study will involve a randomized, double-blind clinical trial comparing creatine monohydrate to a placebo.

Stroke is one of the most impactful health conditions worldwide, currently being the leading cause of disability and the second leading cause of death globally. Approximately 85-90% of strokes are ischemic, primarily caused by acute arterial occlusion, leading to an area of cerebral, spinal, or retinal infarction. The size of the lesion depends on the affected blood vessel and the duration of the occlusion, as well as cerebral autoregulation, blood pressure, blood sugar levels, and many other factors. After the acute phase, treatment is based on secondary prevention and rehabilitation, with few treatments currently available that focus on functional recovery once the infarction has occurred. Stroke survivors experience a loss of functionality, a decline in physical capacity associated with a decrease in muscle mass, sarcopenia, cognitive impairment, and an increase in anxiety and depressive symptoms.

Creatine is a widely studied nutritional supplement, mainly in athletes, where it has been shown to improve training adaptation and physical performance. Its effects on energy metabolism, as an anti-inflammatory, and on calcium homeostasis have been described. There are also studies indicating possible musculoskeletal benefits in the elderly population. Given its role in improving physical performance and muscle mass, considering the significant impact of these conditions on patients who have suffered an ischemic stroke, and considering its antioxidant and anti-inflammatory effects, we propose a pilot study to determine the effectiveness of creatine supplementation in stroke patients. This supplementation could potentially lead to greater physical and functional recovery following an ischemic stroke.

A randomized, double-blind clinical trial will be conducted. The trial will include a group supplemented with creatine monohydrate at a dose of 0.3 g/kg/day for 7 days, followed by 0.1 g/kg/day for 12 weeks, alongside standard clinical practice; and a control group supplemented with a placebo (corn starch maltodextrin), following the same protocol and doses.

Inclusion Criteria:

• Age between 18 and 80 years
• Recent diagnosis of ischemic stroke (from 24 hours to 5 days) .
• Neurological deficit due to the stroke that affects mobility (paresis and/or ataxia) and requires motor rehabilitation.
• Ability to understand and sign the informed consent form, or failing that, have sufficient support to carry out the correct follow-up of the study.

Exclusion Criteria:

• Moderate-severe disability prior to stroke, defined by an mRS>2.
• Unstable or severe clinical situation that prevents active rehabilitation.
• Neurological deficit due to stroke that prevents walking without help from another person. The use of support with a cane, crutch or walker is permitted.
• Moderate or severe dysphagia that makes therapeutic adherence difficult.
• Use of creatine supplements in the last 3 months, or use of anabolic products in the last 3 months.
• Severe kidney disease (GFR <30ml/min/1.73 m2).
• Musculoskeletal pathology that prevents assessment of muscle strength. For example: fractures, severe osteoarthritis, ligament tears or tendinopathies.
• History of allergic reactions to creatine.
• Pregnancy or breastfeeding.
• Simultaneous participation in another clinical trial.

Data obtained through this study may be provided to qualified researchers with academic interest in Creatine supplementation and stroke. Data will be shared subject to acceptance by the research team. Data or samples shared will be coded.

Data requests can be submitted starting 12 months after article publication and the data will be made accessible for up to 24 months.

Access to trial IPD can be requested by qualified researchers. Data will be shared subject to acceptance by the research team.

A professional from the pharmacy service, who will not be involved in data collection or participant care, will handle the blinding.

The care staff responsible for patient care will be unaware of each participant's assignment group.

Blinding may be broken if a serious adverse effect related to the supplementation is suspected in one of the participants.