Little and large: 6ft 4" Michael Phelps towers over 4ft 8" Simone Biles in photo that shows the height difference between America's Olympic stars

  • Michael Phelps is 31, stands at 6ft 4" tall and has won 28 Olympic medals
  • Simone Biles is just 19, 4ft 8" and won her third gold medal Sunday night 
  • He was in rehab last year and she was put up for adoption aged six
  • Each faced hurdles, but they are now America's biggest Olympic stars
  • Biles uploaded a photo of the pair showing the height difference

Michael Phelps is 31 years old, stands at 6ft 4" tall and has won 28 Olympic medals during his long swimming career.  Simone Biles is a newbie to the Games at just 19, is 4ft 8" and won her third gold medal Sunday night.

He was in rehab for substance abuse last year and she was put up for adoption when she was only six year's old because her mother's drinking and drug use. 

Despite their vastly different back stories and physical attributes - demonstrated in a hilarious photo of Phelps towering over Biles which she posted on Twitter earlier this week -  they are now America's biggest Olympic stars, albeit at opposite ends of their respective careers.  

Height difference: Michael Phelps stands at 6ft 4" tall and Simone Biles is just 4ft 8"

Emotional: Michael Phelps couldn't hold back the tears after he took gold in his very last Olympic race on Saturday night

Emotional: Michael Phelps couldn't hold back the tears after he took gold in his very last Olympic race on Saturday night

Gold medalist: Simone Biles, along with Michael Phelps, is America's biggest Olympic star 

Gold medalist: Simone Biles, along with Michael Phelps, is America's biggest Olympic star 

Phelps, who was once so scared of putting his head in the water that instructors allowed him to float on his back, was the youngest American male swimmer to appear at an Olympics in 68 years when selected as a 15-year-old for Sydney in 2000.

At Athens in 2004, his haul of six gold and two bronze medals was hailed as one of the ‘most amazing performances in Olympic swimming history’. Four years later in Beijing he was even better, winning all eight events.

In London, he won four gold medals and two silvers and announced his retirement.

But it wasn't always plain sailing for Phelps. News headlines have told the story of his marijuana smoking and champagne-fuelled binges.

Tearful: Phelps eyes were dry until the moment he heard the Star-Spangled Banner play for him one final time Saturday

Tearful: Phelps eyes were dry until the moment he heard the Star-Spangled Banner play for him one final time Saturday

Medals: Phelps brought home five golds and a silver medal for Team USA at the Rio Games 

Medals: Phelps brought home five golds and a silver medal for Team USA at the Rio Games 

Family: Baby Boomer (held by Nicole Johnson) gave his grandmother a supportive hand as she nervously watched her son's final race

Family: Baby Boomer (held by Nicole Johnson) gave his grandmother a supportive hand as she nervously watched her son's final race

SIMONE BILES 

Sport: Gymnastics 

Height: 4ft 8"

Weight: 105lbs

DOB: 3/14/1997

Birthplace: Columbus, Ohio

Hometown: Spring, Texas

High School: Homeschooled (Spring, Texas) ‘15 

Olympic medals: Three gold medals 

MICHAEL PHELPS 

Sport: Swimming 

Height: 6ft 4"

Weight: 185lbs

DOB: 6/30/1985

Birthplace: Baltimore, Maryland

Hometown: Towson, Maryland

High School: Towson High School (Towson, Maryland) ’03

Olympic medals: 23 gold, three silver and two bronze

On one occasion, he was arrested after leaving a casino and racing home at 85mph in a 45mph zone in his Range Rover – almost two times over the legal limit.

The incident marked Phelps’s second drink-driving offense in ten years and led to a stint in rehab, sessions with Alcoholics Anonymous as well as a six-month suspension from swimming.

He was close to going to jail and a judge warned him he was ‘powerless over alcohol’.

But the American sporting hero had a brighter future ahead of him.

Celebration: Simone Biles reacts to the news she has picked up her third gold medal in Rio. She became the first American woman to secure Olympic gold on the vault Sunday

Celebration: Simone Biles reacts to the news she has picked up her third gold medal in Rio. She became the first American woman to secure Olympic gold on the vault Sunday

'Superhuman': The 19-year-old averaged 15.966 during her two vaults Sunday, well clear of silver medalist Maria Paseka

'Superhuman': The 19-year-old averaged 15.966 during her two vaults Sunday, well clear of silver medalist Maria Paseka

Phelps welcomed his first child Boomer into the world in May with his fiancee Nicole Johnson, who was crowned Miss California USA in 2010.

The couple have been dating on-and-off since at least 2009, officially splitting late in 2011 before rekindling their romance in 2014.

The have been engaged since February last year and announced the pregnancy in November.

Phelps brought home five golds and a silver medal for Team USA at the Rio Games. 

The Olympics bid a rapturous farewell Saturday to the greatest swimmer of all time as he won his 23rd gold medal.  

Family photo: Shanon Biles pictured with three of her children -  Tevon (left), Simone (center) and Ashley (right)

Family photo: Shanon Biles pictured with three of her children -  Tevon (left), Simone (center) and Ashley (right)

Destined for greatness: Simone is pictured on a jungle gym as a young girl

Destined for greatness: Simone is pictured on a jungle gym as a young girl

Biles was born in Columbus, Ohio, and was six when she was adopted, along with her younger sister Adria, by her maternal grandfather, Ronald Biles, and his wife Nellie.

Her biological mother, Shanon Biles, could no longer take care of her four children due to her drug and alcohol addictions.

Shanon’s eldest boy and girl, Tevon and Ashley, were taken in by Ronald’s sister.

They had spent their early years in and out of foster care in Ohio.

Simone’s biological father, Kelvin Clemons, also struggled with his own addictions. 

Adopted parents: Simone was six when she was adopted by her maternal grandfather, Ronald Biles, and his wife Nellie (pictured together in July 2016)

Adopted parents: Simone was six when she was adopted by her maternal grandfather, Ronald Biles, and his wife Nellie (pictured together in July 2016)

Simone and Adria were raised in the small town of Spring, Texas and came to call their grandparents ‘mom and dad’. They enrolled her in gymnastics aged six after she became enthralled with the sport.

Biles is currently the three-time, reigning world champion and holds the record for most gold medals – ten - won by a female gymnast in the history of the World Championships.  

She became the first American woman to secure Olympic gold on the vault Sunday. 

'Superhuman' Biles' three gold medals in Rio are the most by an American female gymnast in one Olympics. 

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