tonight on "nightline," the wonder boy. he's a fitness super star with a hit dvd, rock hard six-pack abs and astounding hook. but he's only 11 years old. how young is too young to be this hard core. hotel confidential. his mission, uncovering the dirty little secrets of hotels and motels. what does he know that we don't? plus, god save the phone box. they are as british as fish and chips but these big red booths are disappearing.

tonight, we found out why and try on olympic feat of our own. >> how many is that? good evening. i'm terry moran. a country where obesity is the most dangerous health threat for children, it seems commendable that an 11-year-old is choosing exercise over video games. and with wash board abs of envy, is it healthy to be that toned in elementary school or is it taking fitness too far? here is juju chang want encore presentation. >> reporter: who, other than justin bieber e will get this kind of welcome from a grade school. it's a surprise appearance by

their pint sized celebrity trainer. just 11 years old, that's right. 11. c.j. has motivated the 450 students at the school to get on their feet. but today, the first time they have ever met him in american. because this is how he has trained them. >> now, up. jump, then, repeat. >> it's hard. >> it is. >> reporter: c.j. senter is the workout kid whose videos promise to make him into minigla-gladias like him. and he puts me to shame. how many of these do we have to do? >> when you get tired. >> reporter: okay i i'm tired now. he has been on the fitness kick half his life. since age 5.

it extends to his diet. do you eat candy? >> will, i eat candy, but not a lot rather little. do you eat junk food? >> no, i like fruits and vegetables. >> reporter: while there is worry about obesity in american kids there is concern about kids training and dieting like olympic athlete. >> in my practice now, i have seen it doubles with kids with overuse injuries. they are doing more now. >> reporter: a lot is do to the hours of practice in organized sports. but because all their heroes now look c.j. >> i do it once a day. >> reporter: that is amazing. >> the last three years, i last about ten pounds. >> reporter: ten pounds? >> i think three or four weeks.

>> reporter: were you heavier? >> yeah. >> reporter: that may be wishful thinking. but we found kids that were body conscious. do you want to have muscles like c.j.? >> almost. >> reporter: nice. every doctor we spoke with about c.j. say agrees, what he is doing is better than playing video games. whether it's the pressure of little league or martial arts, they can overdo it. how much is too much for a 10-year-old? >> the guidelines we have, kids can work out for up to an hour a day. and that means mixing water breaks 15 or 20 minutes with an activity. >> reporter: for extreme miniathletes, physical can be layered with emotional harm. richard sandraft, little hercules, was 8 years old when he was known for his stunning

physique. his parents were putting him on an exercise track. and the parents denied it. some people think he is too young to be that ripped or have that many six pack abs. >> it with wasn't anything he set out to do on purpose. it was just exercising and normal play for a purpose. he developed a physique. >> reporter: you are not forcing him to do push-ups? >> not at all. >> reporter: he did it with c calistheni calisthenics, not weight lifting. his parents have given athousands of dvds.

tell me how many you have sold and how many you have given away? >> we have given away -- >> about as many as we sell. >> reporter: c.j. dreams of one day plays in the nfl. if that doesn't work out, he already built on impressive body of work. i'm juju chang for "nightline" in marietta, georgia. good for him. thanks to juju chang. next up, dirty hotels, beware. we go on an extreme makeover mission with the hospitality guru. whoa, look at all those toys.

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if you have ever stayed in a bad hotel, you know there are

some problems that even continental breakfast and free hbo can't fix. you are able to meet one guy that who makes sure that bad stays don't happy to good people. he is a hospitality crusader. so what can you learn from him for the next time you check? ? here is matt gutman. >> reporter: his shtick is mattress flipping and cockroach kicking. >> we have a very ugly bedspread. >> look at this. >> reporter: and a suit in the searing heat. >> i can see some stains here. >> reporter: despite the appearance of a pit bull, he is here to help. why to you make that call? >> well, we're struggling right now just to stay afloat. >> reporter: e see, anthony is a

hotel fixer. if you look at the travel channel show "hotel impossible," you think it would be tear free. but most of these are mom and pop operations, real people who need anthony's help. >> wow. it's something i dreamed about having but we couldn't afford to have. >> reporter: what you might call is flea bag is all they go. i acampaigned him to day tone that beach. >> if we don't get help, we will not be here much longer. things are gotten bad. >> reporter: they are hardly alone. by the end of 2009, nearly 40,000 hotel employees have been laid off. and many with permanent no vac vacancy signs. >> who want fos see dead

flowers. >> reporter: we randomly chose a room to inspect. >> did you set me up? >> reporter: you just stepped on a cockroach. >> maybe pee did in here. he started as a bellboy and worked his way up. now, he is a consul substantiate, overing hotels and people like us valuable tips. his top four. make sure the hotel lock works and use it. check the floor. bed bug search. and put your suitcase on a metal stand, not a wood one. and the grout, he wants to be

toothpaste waste. >> what needs be fixed is not fixed. and what needs to be clean is relative relatively clean. and he is finding out guests really want. >> i don't like these pillows. most throw them on the floor. and we put them on the bed. >> reporter: the owners, it's tough love. >> put that in your hand. that is more than a month's worth of cigarettes. >> if it doesn't pick up this month, we might not make it through the summer. >> reporter: they are owned the hotel for 20 years. it's all they know. >> it's humiliating to have someone come in here and tell you you don't know what you are doing. >> reporter: they have no choice but to trust this hotel doctor and the bitter medicine he prescribes. under the guidance of his side kick, the painting, rearranging,

plumbing, steam cleaning the rooms beginning. and perhaps the beauty of the show is anthony belief in redemption. >> is there hope that it's crumbling around you? >> i put systems in place and i show them a map. you walk on this map, i guarantee you your reputation is on the line. >> oh, wow. >> reporter: and it is turned around. the work is always done by the end of the show. i may be a layer of point thick but it makes the hotel impossible possible. i'm matt gutman for "nightline," daytona beach, florida. >> and the season finale airs monday on the travel channel. just ahead, god save the phone box? why the iconic big red booths are disappearing from the streets of london. hey america, even though

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and my co-anchor bill weir joins us now from london with the late fres the olympic games. bill? >> reporter: terry, twas another day of liquid gold. missy franklin and michael phelps win in the pool. and a fresh face to root for tonight and behind. 15-year-old katie ledeki won gold in the 800 meter free. american women's soccer team win. and team usa is atop the medal board. i have to an admit, i with was

looking forward to phoning in the results from an iconic red phone booth, but as judy foudy tells us, times are achanging. >> reporter: never mind the queen there is another british icon that could use help from above. the red telephone booth, so convenient, to british, so red. seems like they are on every corner here in london. but their days could be numbers. we rang up on expert to find out why. >> this is julie foudy from "nightline" looking for richard. >> reporter: he was quick to correct me on one thing. >> they are called telephone boxes. >> reporter: they do all mel smel like this one. >> one of the things this london. they are calling cards for

girls. >> so the iconic phone boxes turned into brothels. why is it such an iconic image? >> for people my age and older, they have grown up with the phone boxes. the problem with the red phone boxes, they are first restored in the 1930s. so they are quite old. >> reporter: could you consider them endangered? >> they are endanged to some extent. especially in the rule areas. >> reporter: 30 years ago, there were 80,000 across england. now, less than 11,000. >> and people were shocked and surprised to see the icons they have grown up with being removed. >> reporter: blasphamy.

some have been turned into churches a library, even a pub. what is the weirdest things have seen them converted to? >> some people have used them in shower boxes and one person, a fish tank. >> reporter: that got me thinking. with the olympics and all, what if -- how many people do you think you can fit in one of those? >> eye don't me. i'm in here with my rock sack on the way to work and i think we could fit another five people easily. if you sat on top of each other, we could get ten people in here. >> reporter: we have to try that. does anyone want to get in the phone booth? you know you want to. so we did. turning london's piccadilly

circus into, yeah, circus. the world record we are trying to beat is 16. set by a group of gymnasts in 2007. >> seven? >> reporter: never mind they were prepubescent and flexible. stuck it in and suck it in. hands in the air. but i do feel like i bonded with humanity where you with reach out and touch someone. in london, i'm judy foudy, for "nightline." >> do you think we could get that in the "nightline" office? have a great weekend. i will see new london, full olympic coverage next week. have a great one. >> you too, bill. thanks v