Feeling down? A bad mood can be tough enough to break, but when you feel as if your entire life has hit a rough patch, it can be impossible to see the proverbial "bright side."

Harvard-trained happiness researcher Shawn Achor has spent years studying the topic and says that there are two simple things you can do every day to boost your happiness to new levels, not just in the moment, but also for the long haul. The first, exercising, is a commonly cited happiness booster, but not quite for the reason everyone assumes, Achor tells Oprah in the above video from "Super Soul Sunday."

"When people exercise, we talk about endorphins, but endorphins are just short-term," he explains. "The reason why exercise is valuable is it trains your brain to believe, 'My behavior matters,' which is optimism."

This longer-term optimism that results from exercise -- even just 15 minutes of fun, cardio activity -- actually creates a ripple effect across various parts of your life. "[It] causes you to create an entire constellation of positive habits around you," Achor says.

The second way to boost your happiness is to meditate, but, once again, Achor offers a fresh, practical perspective. It's not about blocking out a 20 minute chunk of the morning to do transcendental meditation every day, he says. It's much simpler than that.

"What I'm trying to do in this research is keep the bar as low as possible," Achor explains. "For me, meditation's hard because I feel like I have developed 'cultural attention-deficit disorder,' where because we have so much stimulation, I feel like I have trouble focusing on things for very long. So when I try to meditate, my brain gets so scattered."

If this sounds familiar, Achor suggests trying an easier version of meditation that he has seen produce powerful results among participants in his studies.

"Here's what we found: For two minutes, watching their breath go in and out -- literally two minutes -- it gave their brain a new pattern," he says. "[It went from] multitasking to single-task... Their happiness levels improved, their stress dropped and, amazingly, the stress of the people around them dropped as well. It starts to cause this chain reaction."

Still feeling too distracted? Achor also shares his advice for shutting out the noise in your life.

"Super Soul Sunday" airs on Sundays at 11 a.m. ET on OWN, with all-new episodes returning in February. Find OWN on your TV.