I recently (about a month ago) introduced high intensity, puke-inducing, balls to the walls prowler sled pushes into my 3 times a week routine strength training sessions.
First week it felt like I could have found a new method for suicide! I kept on going, kept on pushing out those 7 rounds of 25 meters (each way).
Second week, I am sleeping better, my joint pains have all but disappeared. I can feel a huge difference in the way I walk. Walking has become faster, more deliberate such as lifting feet clear off the floor and even walking faster in public spaces without feeling shortness of breath.
Week three - I suddenly feel my mood, my speech and my thoughts have improved. Energy levels are high and I'm listening to music again, enjoying the small things again. I've phoned old friends I lost contact with many years ago for catch up coffee and I no longer have my usual thick-as-fog shameful sense of depression that I wake up with. It's there, but it doesn't intrude constantly like it used to. (I have tried meditation but I found it too difficult.)
I don't know how long this will last but I am almost certain that the high intensity blood pumping full body workout prowler sled pushes are the shit.
Highly recommended.