10 000 steps roughly equal to 7-7,5 km walked.<p>To stop the shrinking of important parts of brain you need about 5 km&#x2F;day average in a week (you can do 35 km in Sunday, for example). BTW, 5 km&#x2F;h is close to typical walking speed, not fast and not slow either.<p>So yes, you do not need 10K steps a day. Slightly above 7000 steps per day would suffice.