It’s hard to compare athletes from different eras and from different sports. But when it comes to the number of Olympic medals won, there’s no doubt that American swimmer Michael Phelps is second to none. The 31-year-old has won a total of 28 medals during his Olympic career with 23 of them being gold, three being silver and the other two bronze. Phelps helped the American men’s 4×100 metre swimming relay team take the gold on August 13th in what could very well have been his last ever Olympic appearance. Phelps has stated that he won’t compete at the 2020 Games in Tokyo, Japan, but since he’ll still only be 35 years old in four years time, he may very well change his mind before then.

The gold medal in the relay was Phelps’ fifth of the 2016 Games in Rio de Janeiro and he and his teammates Nathan Adrian, Ryan Murphy and Cody Miller set a new Olympic record in the event with a time of three minutes and 27.95 seconds. He also won a silver in the 100-metre butterfly event. Phelps made his Olympic debut back in the summer of 2000 and after the relay he told the media, “This is how I wanted to finish my career. I’ve lived a dream come true. Being able to cap it off with these Games is just the perfect way to finish.” His 28 medals are 10 more than the closest runner up as Soviet gymnast Larisa Latynina accumulated 18 of them from 1956 to 1964 with nine being gold.

The 6-foot-4-inch swimmer has a 79-inch wingspan and scientific tests have shown that his body typically produces less lactic acid than his opponents and this enables him to recover much quicker. This is a huge advantage when swimming several races the same day. In addition, his ankles are double jointed and basically act like flippers in the water since they’re about 15 degrees more flexible than most other swimmers. And let’s not forget that his shoe size is 14. When it comes to all-time Olympic medals, there are 31 nations that have won more than Phelps’ total of 28. That means he’s won more than 175 other countries have.

Phelps also said he was retiring after the 2012 Olympics in London, England and then spent a bit of time in rehab two years later after a second drinking and driving charge. He felt his life was in disarray, but he got it back on track when his son Boomer was born. The native of Baltimore, Maryland leaves the 2016 Olympics with the most gold medals and medals in total in individual events and his eight gold at the 2008 Games in Beijing China is also a record for one Games. Phelps holds numerous other Olympic and world records and if this is indeed his last competition on the big stage it’ll be interesting to see just how many years his record 28 Olympic medals lasts.