Little is known about effect of exercise for patients with lacunar stroke, no studies have investigated the feasibility or effect of aerobic exercise in this subgroup of stroke. The patients have few and temporary symptoms and are therefore early discharged from the hospital. After an cerebral infarct the patients have increased risk of recurrent stroke and they are at risk of developing cognitive deficits or vascular dementia over time. Researchers want to investigate if high-intensity training at home in the acute phase has an effect on aerobic fitness, endothelial response and health profile in this potential fragile group of patients. We hope to increase the patients´ physical and mental function, and thereby prevent a recurrent stroke and slow the progression of vascular diseases.