Sport is often thought of as a young person's endeavour, all too often built on cruelly short careers. But for a few whose accomplishments are so great, worldwide fame and respect follow into retirement and beyond. Manny Pacquiao, who announced his retirement from boxing on Wednesday, will be one of them. He is the world's only eight-division champion, after a career that spanned 72 fights. He lost just six. In 2015, he took on Floyd Mayweather in the "Fight of the Century", the highest grossing boxing match of all time, which took in more than $900 million. He has also brought his fight to politics, starting in 2007 when he tried and failed to enter the Philippines' Congress. In 2010, he won a seat in the lower house, representing the southern Sarangani province. In 2016, he won a six-year term in the upper chamber. Now, he is planning to run for the presidency in elections in 2022, his most difficult challenge yet. Perhaps boxing is the perfect preparation. Leading American sports broadcaster ESPN calls it the toughest sport in the world. It is a complex mix of spectacle, business, rivalry, endurance, power and even moral conundrum: for years, the World Medical Association has called for boxing to be banned due to its potential for serious short and long-term harm. For many in the medical community, a sport in which opponents set out to hurt one another is inexcusable. But boxing's proponents argue it is a lifeline to even the most deprived in society, teaching discipline, humility and respect, fostering a sense of community and reducing violent crime. American boxer Marvin Hagler summed up why difficult beginnings have created almost all great boxers: "It's tough to get out of bed to do roadwork at 5am when you've been sleeping in silk pyjamas." Mr Pacquiao epitomises this idea, growing up in poverty in the south of the Philippines, eventually smuggling himself to the capital, Manila, as a teenager. It was there that he started to compete professionally. He is now a hero in the Philippines and would be well-placed to rally popular support to tackle the country's many challenges: there are almost 17 million Filipinos living in poverty, and dangerously high crime rates. He would not be the first sportsman to enter office. Imran Khan, Pakistan's Prime Minister, was previously a professional cricket player. Arnold Schwarzenegger was elected Governor of California after a diverse career that saw him become the best-known body builder of all time, as well as a world-famous actor. Is boxing about to get its first major political leader? Muhammad Ali, the most famous boxer of all time and a champion of civil rights in the US, once said "service to others is the rent you pay for your room here on earth". After a 26-year career, Mr Pacquiao is trying to do just that. It remains to be seen whether he will be successful, but he certainly has the CV.