Specifically, people ages 50 and older experienced boosts to brain health following exercise sessions lasting 45 minutes to an hour at a minimum of moderate intensity. The study was recently published in the British Journal of Sports Medicine.
Researchers analyzed 39 studies published through 2016 in an attempt to look at the effects of exercise on brain health in this age group. They examined aerobic exercise, resistance training (i.e. weights) and a combination of the two. They also studied yoga and tai chi.
Aerobic exercise led to greater improvements in cognitive abilities (think: reading and learning, reports the BBC), and resistance training enhanced memory and executive function. The status of a person's current brain health was immaterial.