Just how resistance training initiates changes in cognition remains somewhat mysterious. Ms. Liu-Ambrose said that "we now know that resistance training has significant benefits on cardiovascular health" and reduces "cardiovascular risk factors," which otherwise would raise "one’s risk of cognitive impairment." She speculates that resistance training, by strengthening the heart, improves blood flow to the brain generally, which is associated with better cognitive function. Perhaps almost as important, she added, resistance training at first requires an upsurge in brain usage.