- Learning a language – It slows brain aging, makes mentally demanding tasks to be performed better.
- Exercising – There are dozens of scientific researches that show exercising is good for your health and brain. Improves blood circulation in brain and increases the size of hippocampus, which is involved in learning.
- Meditation – Many areas will get more active after sessions of meditations according to a research from Harvard. If you have any question or don’t know how to get started check out meditation subreddit.
- Tutoring – If you teach someone about a topic you are expert or at least familiar with re-affirms what you know.
- Writing – Writing by yourself increases your ability to express yourself better, also makes you learn a lot by doing research for your writings. Easiest way to start blogging.
- Video games – According to a research from Leiden University from 2012 playing video games develops working memory. Only half an our a day increase gray matter in the brain.
- Playing an instrument – Music activates many areas of your brain.
- Reading – According to a study from Emory University reading about something activates the same neural connections that you use in real life. For example if you are reading about driving it triggers the same neural connections as when you are actually driving.