The authors base their findings on 673 patients all of whom had had a first stroke and were taking part in the Ischemic Stroke Genetics study.
The participants were quizzed about their levels of regular physical activity prior to the stroke, and the impact the stroke had on their lives was assessed twice, three months apart.
Half the patients said they were physically active less than once a week. A further 28.5% said they exercised one to three times a week; while one in five (21%) said they indulged in physical activity four or more times a week.
Those who exercised less frequently tended to be older - 45% of them were over 70 - and they were more likely to be female and have pre-existing conditions, such as heart failure, high blood pressure, or diabetes.
But even after taking account of these factors, those who were moderately to very physically active were still less affected by their stroke than those who had taken very little regular exercise.
They had higher scores on the Barthel Index at their first assessment. This measures how well an individual is able to take care of him/herself by doing routine tasks, such as getting dressed, bathing, etc.
They also had fewer functional problems, as measured by the Oxford Handicap Scale, which evaluates the degree of physical/neurological impairment and its impact on independent living.
At the second assessment, three months later, those who had exercised regularly before their stroke still had higher Barthel Index scores.
The authors caution that their results would need to be confirmed in a larger group of patients before any firm conclusions could be drawn. But they suggest that there are several plausible explanations for the impact of previous exercise on stroke.
Exercise improves the physical tone of arteries, which eases blood and oxygen flow around the body, including to the muscles and the brain. This could both help build up resilience to the sort of onslaught a stroke has, as well as speeding up recovery, they suggest.