[super_mario]

Vigorous aerobic exercise does wonders for your mood and it doesn't have to be that long. Half an hour will do the trick. Make sure you raise your HR to above 80% of your HRmax. This does wonders for your brain, it makes it produce BDNF, which helps you learn and retain memories better too, and improves your mood.

I know it can be really hard to make yourself do it, esp. when you feel down, but after you are done, you will be asking yourself what were you objecting to in the first place.

If you want to learn more about the link between exercise and brain health read "Brain Rules" by Dr. John Medina or watch his Google talk by the same name:

https://youtu.be/IK1nMQq67VI

He also has "Baby Brain Rules" on parenting techniques to help your new baby get a good start (some of the stuff you need to do way before you even get pregnant/decide to have a child).