Source: http://felissful.com/5-great-mental-fitness-exercises/
I watched a number of movies that discuss various elements of martial arts, and something that was emphasized frequently and specifically is the connection between the mind and body, which is something that I believe differentiates martial arts from other forms of self-defense. In martial arts there is a strong element of improving self-awareness both spiritually and physically through finding the balance and connection within yourself, whereas self-defense tends to focus on conflict resolution in a practical sense.
When we think of the practicality of physical fitness, the ability to accomplish certain tasks or exercises come to mind (e.g. lifting a specific weight or running a certain distance) and these relate to the attributes of physical fitness such as power and endurance. The same concepts can be applied to mental fitness, because the ability to accomplish certain tasks or exercises using your mental faculties is very real (e.g. solving a puzzle or concentrate on a talk).
However, a more subtle aspect of mental fitness is resilience, which is not just about having the will to persist through situations that we find mentally challenging, but also to resist and control our feelings and actions when the instinct is to act on our impulses. Some people would describe this as the feeling of losing your 'inhibitions', such as the case when you indulge in too much alcohol or use chemical stimulants to enhance or dull certain senses. Not surprisingly, developing your mental fitness means that you also improve the ability to resist against the sudden loss of control due to external or physical influences.
In the past months I have explored many aspects of mental fitness and its connection with physical fitness, and I believe that one aspect of maintaining both areas of fitness is to try and find the right balance for you. Whenever I have found myself engaging in lots of online conversation, I try to think of ways to convert these thoughts into actions so I can train myself better. The best example I can think of is how 
No doubt some of you have also found it slightly addictive to be upvoting and commenting for what your voting influence is worth. I have often found myself running out of steem/steam and having to step back to see how to balance my time and energy better on Steemit. And I don't mean just jumping on Discord and Steemit Chat and spending more time talking with people, but perhaps try to see how you can turn conversations into actions and activities that will provide just as much benefit to the community without necessarily making it about increasing your SP or BSD.
I think this is going to be a big part of my goal on Steemit in 2018, and I hope this will be reflected in my bounty contests and other posts to promote the idea of #mental-fitness, which is just a small part of my contribution in #makingsteemitgreat-again.