Lou Ferrigno is angry at his brother (and you won't like him when he's angry) but instead of turning green ... he's skipping right to threatening a lawsuit over his bro's exercise equipment business.

Lou and his brother Andrew had a legal skirmish a few years back and eventually reached a settlement ... which Lou says limits Andrew to using the phrase "Andrew Ferrigno equipment." He also has to make it clear his biz has no affiliation with Lou's companies and websites.

Lou claims Andrew has violated the order because he's using the word "exercise" in the name of his store ... and insists the disclaimer is nowhere to be found on Andrew's website or social media.

Lou's lawyers sent a letter threatening to sue ... and Andrew tells us since then he's met all of his brother's demands. Well, except for removing the word "exercise" from his store's name.

Andrew tells TMZ, "My brother has money, so why does he need to suck me dry? I am so bewildered by the fact that an actor of his stature would stoop so low as to sue his own brother twice."

Here's NFL running back Chris Johnson working out SO DAMN HARD at an L.A. gym Monday, he went and dry-heaved in the parking lot ... and TMZ Sports has the video.

Johnson was haulin' kettlebells outside of the Unbreakable Performance Gym in West Hollywood -- where trainers pushed him to the brink of hurl city.

Now, we never saw Johnson actually blow chunks ... but he was close ... and eventually got back to the weights to finish his workout like the monster that he is.

Fun Fact -- Unbreakable is same place where Diddy raced (and BEAT) NFL star Dashon Goldson in an uphill sprint last month!

Nicole Murphy likes 'em big ... real big ... and younger from the looks of things down on Miami Beach.

The reality star was hanging with enormously buff Brit model David McIntosh over the weekend. Considering she split with ex-NFL stud Michael Strahan last August ... it definitely looks like the lady has a type.

But sources connected to Nicole tell us despite their perfect physiques (she's freakin' 47) being so close ... they only hooked up for a photo shoot. No banging. Not yet.

The two of them together though -- quite a body of work.

John Cena doesn't think there's an age limit on weight room domination ... telling TMZ Sports 69-year-old Vince McMahon is an absolute TERROR on the racks.

The WWE superstar was out in NYC (wearing only a t-shirt in the freezing weather) when we asked him about VM's recent Men's Fitness Magazine cover where the guy looked like an AARP Incredible Hulk.

Check out the clip -- Cena says that McMahon's biceps aren't just for show and the guy can lift like a man half his age ... and even rivals Cena himself.

Makes you want to call your granddad ... and ask him why he's slacking off.

Alec's hot wife has been using her Instagram account to show us that there isn't anywhere she can't get her zen on. Check out her 10 most inventive poses!

6. The Stylist

Fact: Our photog Adam got a hernia from working out like an idiot in the gym.

Fact: 50 Cent is kind of an expert when it comes to working out.

So, when Adam ran into 50 out in NYC Monday, he asked if 50 had any workout tips that could save him from another bout with the dreaded organ protrusion.

Welcome to the gun show ... "50 Shades of Grey" star Jamie Dornan proved his body is definitely hard core enough to play Christian Grey.

Dornan's muscles look like they are about to explode in this impressive pic of him balancing his entire body weight on a workout bench. He says he held the pose for about 2 secs before collapsing in tears. We doubt that.

If '50 Shades' fans were worried JD wasn't hot enough to pull off the role ... they ain't worried any more.

Richard Simmons had visitors Friday night ... cops who were doing a welfare check because he's been MIA for more than year ... and guess what? He's fine.

Law enforcement sources tell TMZ ... 2 LAPD officers showed up to Simmons' Hollywood Hills home at 7 PM. Richard answered the door and showed them in. The cops' feedback -- he couldn't have been nicer and more gracious. They say he was articulate, lucid, relaxed and appreciative of their concern.

Law enforcement sources tell TMZ ... the visit was triggered by a long-time friend of Simmons who sent an email to the L.A. County D.A.'s Elder Abuse Unit last month and said he believed the 66-year-old fitness guru was being abused.

TMZ broke the story, Simmons went radio silent a year ago. He hasn't spoken to his friends, gone to his fitness studio or been seen in public. His friends say there is no way Richard would shut himself off this way. His manager says Simmons is simply depressed over a knee injury.

But we've learned the 2 cops who spent an hour with Richard say he seemed genuinely happy. Simmons, who now has a beard, told them he was "exhausted" after spending 30 years in the public eye. He said, "I just want to spend time with myself," although he says he's in regular touch with the people in his life who matter to him. He was alone in the house Friday when cops were there.

Simmons was walking with a slight limp, which is consistent with the knee injury. As for why he hasn't been to his fitness studio for the better part of last year, he said, "I've got people who run things. I don't need to be there." Until he disappeared he was a fixture at the studio.

Bravo star Greg Plitt's favorite energy drink will not give you superpowers ... so says the company that makes WheyUP -- the product Plitt was plugging when he was hit by a train.

The pre-workout drink contains protein and caffeine, but Shadow Beverages and Snacks wants to stress what should be obvious -- it would never give anyone the ability to outrun a train.

Even though a bunch of empty WheyUp bottles were found near the tracks ... a company rep tells us Plitt wasn't drinking all of them -- he was crushing most of them with a hammer for the promo shoot.

Plitt was a co-owner of WheyUp, and the rep says he had full creative control when it came to his video shoots.

Bravo star and fitness instructor Greg Plitt did NOT die from stumbling on a railroad track Saturday ... he was fatally struck by a train after trying to outrun it ... to prove the effectiveness of an energy drink.

Law enforcement sources tell TMZ ... they have reviewed video of the accident and it shows Plitt standing on the tracks as the train barrels toward him. Shortly before the train reaches Plitt he assumes a runners stance and bolts down the track.

The video shows the train closes in on Plitt as he races at breakneck speed, but he loses the battle and the train "clips" him ... throwing him off the track to his death. It happens quickly and after getting struck he disappears from the video.

And law enforcement tells us they found multiple energy drink bottles near the track and authorities think Plitt may have been hopped up from the caffeine. We're told he was shooting a commercial for the product.

One of the investigators interviewed someone involved in Plitt's video shoot who said Plitt was trying to make the point that the energy drink makes you like Superman ... able to outrun a speeding train.

Bravo's "Work Out" fitness star Greg Plitt was attempting to pull off a dangerous thrill seeking stunt -- just to sell sports drinks -- when he was hit and killed by a commuter train.

Law enforcement sources tell us Plitt was shooting a commercial for a new sports drink -- near the Burbank, CA Metrolink station -- when he attempted to outrun an oncoming train.

Sources close to Plitt say he had worked out near the tracks many times before -- but this shoot turned tragic when he tripped and fell on the tracks ... and couldn't recover in time to get out of the way.

As for why he was on the same track as the speeding train, our sources say Plitt was a highly driven adrenaline junkie. A promotional video for his website is especially eerie now ... since the whole thing was shot in the shadow of a rail yard.

The coroner says Greg's official cause of death is multiple blunt force trauma.

Question: What has 16 pound balls and just pissed off former NFL star Shawne Merriman??
Answer: Some bowling company in Utah that's hawking balls with his catchphrase.

The ex-linebacker has just declared legal war on a bowling company called "Storm" -- which hawks various bowling products on its website ... including a ball emblazoned with the words, "Lights Out."

Of course, Merriman claims he owns the trademark to "Lights Out" -- the nickname he's had since high school -- and demanded the company stop selling the balls ASAP.

But in a lawsuit filed in California, Shawne claims the company refused to comply with his demands -- so now, he's asking a judge to force them to pull the balls from their cyber-shop.

Amanda Bynes is OUT of her manic state ... acting completely "normal" and her family thinks it's nothing short of "mind blowing."

Sources familiar with the situation tell TMZ ... Amanda is off all meds, including Adderall, which caused her to get a DUI.

When you speak with Amanda there is no way you would know she's been diagnosed with schizophrenia and bipolarity. She is completely lucid.

We're told things have stabilized so much, her parents have given her limited access again to bank accounts. She spends her time reading, doing yoga, meditation and pilates ... all stress reducers which doctors say are important for these mental disorders.

We're also told Amanda's recent trip to USC -- where she'd like to enroll as a psych major -- was all planned by her.

Here's the rub. Doctors have told Amanda's family, people with such mental illnesses sometimes rebound and they can be ok for months, only to relapse again.

Richard Simmons is still MIA ... nearly a year after he was last seen, and there are no signs of XMAS or even life at his home.

His friends are more worried than ever. They haven't heard from or seen him since January 11. He hasn't been to his exercise studio in 6 months.

There are no XMAS decorations at his Hollywood Hills house. Friends are not allowed to visit. A housekeeper seems to stand guard whenever anyone tries to enter.

Simmons' rep told us the exercise guru was depressed over a knee injury and that's why he has gone radio silent, but his friends are convinced it is far more serious. They say Richard was the ultimate caring person who loved interaction, and now there is none whatsoever.

Astrid McGuire can handle celebrity asses, but she's done with her husband's -- the famed trainer is calling it quits on her marriage.

McGuire filed papers in L.A. last month after ten very healthy -- on her end at least -- years of marriage to husband, Michael Heier McGuire.

Whipping stars like Christina Applegate and Julianne Hough into shape at Barry's Bootcamp has put her in high demand -- and she's modeled since she was 15.

According to the divorce docs ... divvying up of their property will be handled by a written agreement -- so, should be a clean split.

Astrid's clearly taking her best assets with her.

Riff Raff has been touting his cocaine and molly addictions for 4 years ... but now, the rapper tells us he's giving up both FOR GOOD -- even though he'll continue puffing sticky icky.

The "Kokayne" rapper says he decided to get sober a few months ago ... after he got so wasted the night before a celebrity basketball game for charity he couldn't play.

Riff Raff says that's when he realized he had a bad cocaine problem and had to turn his life around.

The 32-year-old says he isn't going into treatment ... he says fitness is the solution: "Whenever I have the urge to do coke or molly, I just pick up weights instead."

He's been sober a few months -- except for weed smoking -- and Raff says he feels great.

Plus, he's gained 40 pounds ... and is looking swole again.