Mother's exercise during pregnancy enhance baby's brain development: https://www.newscientist.com/article/mg22029433-000-exercise-in-pregnancy-boosts-baby-brain

Mother's exercise during pregnancy enhance baby's brain development: https://www.newscientist.com/article/mg22029433-000-exercise-in-pregnancy-boosts-baby-brain-development/ https://www.newscientist.com/article/mg22029433-000-exercise... I've checked out my year averages for 2019, 2020 and 2021, they were 5, 3.4 and 5.2 km per day. 2020 average is 2/3 of my usual per day walk distance. I try to average 5 km/day in an effort to lessen cognitive decline, because walking rises brain-derived neurotrophic factor (BDNF) level in the blood. BDNF can travel umblical cord and can enhance baby's brain development. So, mothers walking less due to lockdowns is the simplest explanation for that cognitive impairment phenomena I could think of.