depression

I'll second this. Really second it. Getting my heart rate up for a half hour to an hour is my approach. If you are depressed and having trouble doing anything, motivating yourself is going to be difficult. There is no easy answer for that, other than you just have to force yourself. ... at first, at least. For me, at times it has meant having to do things by rote. I wake up, and don't allow myself to think too much. I literally just go through the motions, the way I do any task I have to. I just go to the gym or go running. I don't feel like doing it, but I do my best not to turn it into anything bigger than what it is. Once I am running (outdoors or on a treadmill), I forget how much I didn't want to come in the first place. By the time I am swimming in endorphins and showering, I am wondering why it was such a big deal in the first place. And it has SERIOUS effects. ... like levels me for hours afterward and makes it easier to work.

I don't know what kind of shape you are in. So that may be an obstacle. If you are not used to running, take it slow. At first, make it about getting yourself into the habit. Alternate walking and running so as not to hurt yourself. Keep it modest if it is too difficult. Start with a mile. Walk it all if you have to. Trust me, it will feel insurmountable, but it won't take quite as long as you imagine to get to where you can run a mile, then 2 miles, then 3 miles, etc. Then you will be working on trying to run those distances in less time, etc. and you will be competing with yourself, which in turn will motivate you more.

When things are humming along, it isn't that difficult to get yourself out to run. You look forward to it. And it has a positive carryover into other parts of your life. It's really subtle -- not like you wake up one day and feel eternally happy. It's more that you don't realize you were ever depressed.

I don't really suffer from depression, but I find it to be helpful for a severe anxiety problem that would get the better of me if I wasn't vigilant.

The other thing I'd recommend is meditation. I have a lot more trouble with this (it is a struggle for me, because I have an overactive mind). But it is a good struggle, because it can make a huge difference. You don't have to go full buddhist, but read some things on basic meditation (or find a center near where you live), and start practicing. Even starting with 5 minutes a day just focusing on your breath ,and bringing your mind back in when it wanders, can have VERY positive effects for things like depression. You want to be "in the moment," . ... and then try to carry that attitude through to the parts of your day when you are worrying about something (usually things you can't control or that are in the future) or you are too much reliving things in the past or you just generally feel a malaise. We all do it. Some have a more difficult time getting a handle those kinds of things. It makes you human. But there are things you can start to practice that can be really helpful if you can tailor them to yourself in helpful ways. I'd consider exercise that boosts your heart rate (and helps spur endorphins) if it isn't already part of your day, and seriously consider trying meditation -- even just 5 minutes in the morning and before you go to bed to start can help you begin to build something that may have very positive effects.

Good luck.