With the Coming of the New Year, you'll now be able to test and train your brain a little bit, or a lot.
There are several completely new exercises and, in addition, on every test there is an intensity adjuster. Start low, at 5 or 10 repetitions - and increase to 30 or 40 repetitions as you get more proficient.
This might remind you of a routine at the gym.
As you increase your ability to concentrate and focus, you'll begin to change your brain for the better. As the experts have said, regular workouts for an extended period of time are the key. But even if you can only spend a few minutes a day, with the lower rep settings you can exercise your brain in just a few minutes - with a variety of exercises that focus on different memory and attention capacities - a much more concentrated form of exercise than suggestions to "read" or do "crossworld puzzles," and 2X to 3X more effective, in less time according to a recent JAMA article, with benefits measureable many years into the future.
While they may be fun, crosswords don't have a time element. Time-definite exercise trains your brain to be quicker through enhancement of "neural conduction velocity" which is the scientific term used for "brain speed."
These changes can make your brain act younger by stimulating neural connections and if you are young, increase the potential to learn, store, and recall information. The variety and depth insures that you get a balanced exercise.