Break out the capes, today is National Superhero Day!  Superheroes are REAL and come in all forms, whether they're a celebrity to or someone close to you. A hero is someone who combats adversity and has that inner SISU - perseverance, endurance, bravery. Here are some historical athletes that we think deserve the title of superhero.

1. Muhammed Ali
   

   Muhammed Ali, the most famous boxer in the world, was also one of the most iconic athletes of the 20th century. Growing up in the segregated south, Ali had experienced racism and discrimination firsthand, which clearly didn't stop him. His fight card is full of legendary fights like Sonny Liston and George Foreman.  Outside the ring, Ali was known for his activism and controversially speaking criticism of the Vietnam war. In his retirement, he devoted his time became to philanthropy, leading him to receive the Presidential Honor of Freedom from George W. Bush. 
   
   

2. Ronda Rousey

   Ronda "Rowdy" Rousey is most commonly known for being the undefeated bantamweight champ 12 fights in a row (until Holly Holm took her down at UFC 193). Many don't know that she was also a trailblazer for women entering the UFC. She was the first female fighter for the UFC and really helped expand female involvement in MMA. 
   
   

3. Billie Jean King

   Billie Jean King is considered one of the best tennis players in the world. She has 39 Grand Slam titles, including 12 singles, 16 women's doubles, and 11 mixed doubles titles under her belt. But she's not just known for her athletic abilities, she also known for her contributions to tennis and sports as a whole. She founded the Women's Sports Foundation and she fought for "equal pay for equal play". As a result, she was the first woman to have a major sporting venue named in her honor and first woman to be awarded the NFL Players Association Lifetime Achievement Award.  
   
   

4. Jackie Robinson

   Jackie Robinson was the first African American to play Major League Baseball (outside of the segregated black league), which was a major milestone in the fight for equality. He had a very successful career with the Brooklyn Dodgers from 1947-1956. He was named Rookie of the Year in 1947 and National League Most Valuable player in 1949 which lead the team to win the World Series in 1955.
   

5. Jesse Owens 

   Jesse Owens was a record-setting, Olympic track and field athlete who is often credited as the first black athlete superstar. During the 1936 Olympics, he took home 4 gold medals and set a second for long jump that wouldn't be broken for the next 25 years. And you can bet Hitler was watching! Owens crushed Hitler's dream of Aryan supremacy right in front of his eyes. 
   
   "One chance is all you need" - Jesse Owens

Who's your favorite famous sports hero? Let us know in the comments below.