Walking 3 or 4 Times a Week Grew the Brain's Memory Center by 1% in a Year
The same area usually shrinks 1 to 2% a year after 50, and the walkers remembered better too.
Andrew Huberman · How to Improve Your Memory & Cognitive Function at Any Age | Dr. Alan CastelTaking a 30 to 40 minute walk on three or four days each week grew the brain's memory center by about 1% in a year.
That is the finding described by Alan Castel, a UCLA psychologist who studies memory and aging. The structure is the hippocampus, a small curved area that helps form new memories, and it typically shrinks by 1 to 2% a year in volume after around age 50.
In a randomized trial, older adults assigned to walk were compared with others assigned to stretch, which involved movement without an aerobic workout. The walkers not only added volume, they remembered better a year later.
Castel said researchers do not know the exact mechanism, but he pointed to better mood and better sleep, when much memory formation happens.
Questions people ask
Did it have to be walking?
In this trial, participants were randomly assigned to either walk or do stretching that was not cardiovascular exercise. Castel said there is nothing special about walking itself. He said biking, swimming, and dancing can also be beneficial.
What kind of walk was studied?
The walking group did a steady 30 to 40 minute walk on three or four days each week. Castel also noted separate research showing people who walk slightly faster tend to live longer, though it is unclear whether faster walking causes longer life.
Why would walking change the size of a brain area?
The exact chain is not settled. Castel said the benefit probably works through things like better mood and better sleep earlier in the day. Much memory formation happens during sleep, and sleep quality tends to decline with age.