Not every work day can be perfect--life just doesn't roll that way. But you do have a tremendous amount of control over the quality of your 9 to 5. It's just a matter of being intentional.

Here are a handful of things you can do to make your work day better.

Work out first thing in the morning.

There are so many brain and body benefits to working out that it makes the most sense to do it in the morning so you can reap the rewards for the rest of the day. In fact, researchers at the University of Vermont found that moderate-intensity aerobic training improved participants' mood for up to 12 hours after exercising. Another study found exercising makes people smarter, too, because it creates new brain cells.

And remember, you don't need to make a big thing of it and head to the gym at 5 a.m. Try a simple but effective regimen in your living room: alternate pushups, squats and sit-ups with a minute or two of skipping rope or jumping jacks between each set.

Stop mindless eating.

This is easy to do when you sit at a desk all day long, but it can lead to weight gain. Not only are the health risks of being overweight multifold, but research suggests people who carry around too many pounds are more depressed (PDF) and, as a result, less productive.

In a National Mindless Eating Challenge, an online healthy eating and weight loss program with more than 2,000 participants, Cornell University researchers found that simple eating behavior changes can lead to sustainable weight loss. The most effective strategies include only having healthy foods in reach, always portioning food into a dish instead of eating from a bag, eating something hot within the first hour of waking, eating a snack every three to four hours and slowing eating by setting down a spoon or fork between bites.

Stop drinking soda, especially diet.

This shouldn't come as a surprise. Soda isn't good for you, rots your teeth, and generally should be considered plain evil. Think diet soda is OK? It's just as bad, if not worse!

According to a National Institutes of Health study people who drink four or more cans of soda a day are 30 percent more likely to be depressed than those who stay away from the sticky stuff. The researchers also found that people who drink diet soda are even more at risk than those who drink the sugary variety.

Figure out what's behind your negative emotions.

"Emotions are a way of messaging to us how we are doing in relation to things that are important to us, like our core goals, values, and relationships," says Harvard psychologist and executive coach Susan David in my recent story The Flip Side of Negative Emotions.

Someone who values autonomy, for example, may feel angry and frustrated by a boss who likes to micromanage. If family is important to you long stretches of 16-hour work days may surface feelings of guilt. Or an entrepreneur bootstrapping a fledgling business may experience anxiety if she highly regards financial stability.

The point is to look behind negative emotions to find which of your values are getting less attention. With this knowledge you'll be better equipped to make changes in your life that will make you happier.

Eliminate distractions.

Think of the satisfaction that comes with getting a ton of work done. Distractions are the enemy of productivity, however, so it's important to be vigilant about keeping them at bay, especially if you work in an open office. If that's you, invest in noise-cancelling headphones for getting head-down work done, don't lure people to your desk with a candy jar or other treats, and curb your online activities with browser extensions such as StayFocusd, Idderall, and WasteNoTime. Want more ideas? Check out 7 Ways to Nix Interruptions at Work.

Seek out a good belly laugh. columnist Marla Tabaka recently unearthed several studies proving the health and emotional benefits of laughter and the fact that in the workplace it can increase creativity and productivity. How to get a good belly laugh at work? She suggests several ideas, such as making it a habit to start weekly meetings with a funny YouTube video or silly quote as well as holding long-lunch Fridays during which people can watch a side-splitting movie or video of a stand-up comedian.

Foster great relationships with work associates.

These are the people with whom you'll spend the majority of your waking hours. It helps if you're likeable, though. Wear a smile and aim to be curious about others, optimistic, generous, and above all, authentic. Your favorite people are likely not afraid to share things about themselves that might even make them look bad. In doing so they convey a sense of humility, honesty, and vulnerability that work to lower people's defenses. If you can do that, you're well on your way to befriending them.