My personal experiences go something like this:

* Strength training tends to be a long term benefit. It can be really draining if you put in a difficult workout every session. Copious logging matters to lock in the sweet spot of difficulty, and maximizing recovery rate matters just as much - I found that increasing vitamin D intake did the trick here. But I find that the strength isn't the beginning and end - it helps to have it as a barometer of progress, but it's only one thing.

* Cardio-intensive activity helps my mood throughout the day. Last year I trained judo, which rewards all-around athleticism(though my desire to compete is limited) and it pushed me to take cardio more seriously. I got gifted a Fitbit last Christmas, and took up a jogging routine first thing out of bed by way of pleasing the hourly activity monitor. By focusing mostly on the technique and habit instead of pace, I've improved my form quite a bit, gotten my sleep schedule under control and also hit on another supplement that seems to get my anxiety down(magnesium citrate). However, this led me to something else which I'm still working on:

* I would tend to finish my jog with a cup of coffee and I finally realized last week that I had been letting my caffeine consumption creep up, and this was throwing off a lot of other stuff. My gym numbers were still coming in, but my concentration was mostly shot, and finally at an event Thursday I had one of the free diet sodas and soon after found that I was unusually anxious and had developed an eye twitch. This is too much, I told myself. I had gone through phases of overconsuming and cutting back before, but I was tired of the cycle.

So I decided later that night that I would cold turkey caffeined drinks. I'm still consuming a little bit of chocolate, but it's been an eye-opener. I started having bottled water instead of coffee so as to keep my other habits in the same place. Day one was the most difficult, but my sleep improved immediately and my focus already started getting better on the second day. By the third I realized that I was smiling and engaging with activities better than I had in a long time. My depressive spells never quite went away with the other things, but they seem to be gone after dropping the caffeine(although I'm still getting the eye twitch).

So, yes, it's a lot of things. Sobering up from coffee is something that's helped by getting all my other habits together. If you're starting from a "sodas every day/no exercise/no gym experience" standpoint, this is roughly the path I've recommended to friends:

* Get some resistance bands and start a program with those. They're some of the simplest and most accessible strength training around. Focus on developing some technique and logging your progress.

* Get a fitness tracker and try to hit some of the goals. I like the hourly goals(even though they do not measure when I get up and do housework), others like daily steps.

* Switch either from sugar + caffeine to just sugar or just caffeine. I shifted away from soda about a year into my first job(by - surprise surprise - overconsuming until I felt ill). Then work your way down from there by getting bottled water more often.

* Research supplements. This is not easy with so many options, but there are usually common ones that come up with respect to certain sports and activities.