Heavy bag work should be limited to several times per weak. In each training session, stop and move to another exercise when you become so tired that form and technique fails. If you continue to hit the bag at this point you will run a high risk of unnecessary injury. Move to shadow boxing when your tired.

Art

Art is really the expression of the self. The more complicated and restricted the method, the less opportunity for the expression of one's original sense of freedom.
                                                                                            ~ Bruce Lee

Its that balance between natural instinct and disciplined control.

Meditations
. Alcohol,(beer in this case) can be used to relax before training. Just a small amount does the trick, especially  for someone with lower than .5 percent body fat.
 Its like a potion. A little bit can be of benefit at times. Too much can be a hindrance.
~A little bit can relax you enough that you may avoid injury that you could have possibly suffered due to tightness.
~Too much could cause injury due to reckless technique.
Meditate on these things.

shadow kick boxing

High kicks are very un practical for me now. When I was younger and practicing nearly all the time they could work, I was super flexible and fast and kicking someone in the head was very practical for me. not so now. I dont spend that much time on martial arts. I need practical techniques for my body right now. Low kicks to the shin leg and groin are practical, even the stomach at times. This is practical for most people. A martial art that doesn't require all your time to be able to defend yourself. you need something, simple and effective.

Lately I have been running very short distances. Only for about 4 or 5 minutes. It makes my legs feel great and gives me a boost. Seems to be working for me, I feel strong. I wonder if the longer runs were wearing my body down instead of building it up.
It feels very natural nad is very much a intuitive thing, I run as much as I feel like running, disregarding what any of the norms or "right ways" to run are. Its based on my personal experience and intuition.

60 pushups, different hand placement/width variations.