The “walk a mile in my shoes” series “30 Days” (9 p.m., FX) returns for a third season. In tonight’s installment, Morgan Spurlock, the director of “Supersize Me,” returns to his native state of West Virginia to spend a month working as a coal miner.

Since the debut of “30 Days,” cable television has become thick with occupational reality shows and documentary-style series about crab fishing, truck driving and logging. But “30 Days” remains the most earnest in its attempts to provide viewers with a vicarious experience as well as offer a smattering of thought about the ordeal. Spurlock asks viewers to find meaning in his spectacle. And that’s no mean feat.

During his mining gig, our host works with a 28-year-old miner who argues that their work is destroying the environment. He visits with former miners fighting the surface-mining methods that are destroying the mountain culture of Appalachia and filling its rivers with toxic slurry. He also talks with victims of black lung and the orphans of miners killed in mine accidents.

So why mine? Because in a state with few other job opportunities, mining pays $60,000 a year. And that number is hard to argue with. And so is the fact that more than half of America’s power comes from coal. Sure, it’s dirty, says Spurlock, but we all use it every time we switch on a light. So he has to agree with a coal-industry representative when he says that critics have not come up with a real alternative to coal and coal mining.

Spurlock will not live out all of the experiences this season. Over the next six weeks, an NFL veteran will live for a month in a wheelchair; a hunter will live with a PETA activist; a mother will live with a same-sex couple as they raise their children; an anti-gun activist will live with a hunter; and the series creator returns to live a month on an Indian reservation.

¢ The point at which product placement ends and “drama” begins is blurred beyond recognition on tonight’s “Work Out” (9 p.m., Bravo). I’m usually staggered by the level of tedium on this series. After all, it is about people who do push-ups for a living. But tonight, the eye glazing goes into overdrive as the staff of the Beverly Hills Gym, Sky Sport & Spa prepares to make a promotional DVD.

So, this is a shoot about promoting a gym within a show promoting a gym. But just to show us it’s not all self-promotion and pectorals, Jackie plans dinner with her live-in lover of all of eight minutes, and they discover that there may be trouble in paradise.

Tonight’s other highlights

¢ A repeat “Nova” (7 p.m., PBS, check local listings) looks at the prospects for solar power.

¢ A mishap nearly costs two lives on “Deadliest Catch” (8 p.m., Discovery).

¢ On two episodes of “Law & Order: Special Victims Unit” (NBC), a dead mother-to-be (8 p.m.), Lake opens a cold case only to become a suspect (9 p.m.).

¢ A competitive eater vanishes on “Without a Trace” (9 p.m., CBS).

¢ Mare Winningham guest stars on “Boston Legal” (9 p.m., ABC).

¢ Explorer Bob Ballard explores ancient sunken relics on “Ghost Ships of the Black Sea” (9 p.m., National Geographic).