How do you use HP or MP bar outside of life in video games?
In most video games, you will find some sort of health and mana or stamina indications. Some games use a bar system (HP and MP bar) and some heart vessels some sort of system.
The logic of these systems is to indicate to the players they will have to watch their life or health bar before it goes to zero where they will need to start over again from the last checkpoint. Often time with some inconvenience or frustration of losing either experience points and/ or items. On the other hand, mana or stamina indicator is used to indicate how much 'energy' or stamina is left that allows the player to use certain skills or movements to achieve their goals and objectives. Mana is often used for magic-user, like most Final Fantasy games, whereas stamina indicators can be seen in games like Ashen or Legend of Zelda: Breath of the wild.
So, now what?
We don't have such indications in our physical life and our physical and mental health is so complex that I don't think a simple bar indication can do it justice. However, having the visual or using the concept to externalize our physical and mental state can be helpful to understand where we are and what needs to be done to making sure we cope with our life circumstances. It wouldn't be a perfect indication, but at least it gives us something to work on.
One can use an HP bar or heart vessels to indicate how healthy or energize he/she/they are physically feeling. How can we do that? Well, let's say you are ill or you just finished a game of badminton for an hour, you could say that your HP bar is lesser than when you are well and before you start the game.
One can also use MP bar or stamina circles to indicate how tired he/she/they are emotionally, psychologically or mentally. I always use this indication when it comes to using coping or tolerating skills. For example, when I engaged in emotion regulation skills during a stressful day so that I can keep working, I would see myself using some of the mana from the mana bar. Because by being mindful of my stress level, making the decision to ground myself, and focus on what I was needed to do at work, these decisions and behaviours consume energy.
How is this helpful?
You can use this metaphor to learn awareness and mindfulness skills to understand what you need at that moment to go through the day. Am I well enough to endure through the workday without collapsing? Am I able to maintain my composure after a series of bad events in a day to go make it through a social gathering? What do I need to do so that I can last through the event?
Let me be clear in saying that this is how I generalize the concept of HP and MP into my physical life experience and you might not agree with me. That is totally fine! Then come out with your own indicator that makes sense to you. At the end of the day, you are the only one who needs to relate to the metaphor, no one else.