Feeling great and being in a good mood is a very complicated process made up of numerous pieces and processes. If you're having trouble with your exercise and fitness goals you should consider carefully why that might be. Although there are any number of reasons you may be lacking motivation, like whether or not you're doing something you love for exercise (don't try to make yourself jog every day if you hate running!), it's worth considering other sneakier causes. The science of feeling great is a complicated one!

One aspect of making sure you're "in the mood" to exercise is making sure you give your brain what it needs to be positive and happy. Brain chemistry is a delicate balance of many things, including your metabolism (no, it's not just about energy and calorie burning, but mood too!) and neurotransmitters like seratonin -- which is responsible for feelings of happiness, calm, relaxation, confidence, concentration, and personal well-being. A lack of seratonin can lead to depression, as it does all too frequently for many people in this country.

So how do you help make sure your brain has enough seratonin? A big part is making sure you're getting enough of the amino acid tryptophan, which your brain uses to make seratonin. Most people don't get quite enough tryptophan in their diets, but it can be easily found in high-quality protein foods. And you can help your body process it by getting enough sleep, reducing stress, and supplementing B vitamins if you're short.

What you don't want to do is cave in to cravings when you're feeling down, unless of course you crave protein-rich health foods (wouldn't that be nice). Most people go for "comfort foods" that are high in carbs, sugar, and fat, and low in everything else. The most common explanation for these cravings are the fact that those foods trigger an increase in insulin, which in a round-about way makes us feel better temporarily through affects on amino acids and brain chemistry. The problem is that the effect wears off quickly, and then we're left feeling worse than ever.

If you're really having trouble "feeling good" and getting out there to work out then doing what you can to give your brain a boost certainly won't hurt, and you may surprise yourself and it will really help. Of course if you have serious concerns about the possibility of depression, seek professional help.