WBC welterweight champion Floyd Mayweather has uploaded a 15-second clip to Instagram showing off his impressive punching speed ahead of his May 3 fight against Argentina's Marcos Maidana in Las Vegas.

The 37-year-old asked his 2.4m followers to count how many punches he threw during the 15-second period - and, while we're certain it's over 50, some believe it could have been as many as 64.

It's somewhere in the middle - post in the comments section below if you know the answer!

Mayweather is the overwhelming favourite to win his next fight at the MGM Grand and appears to be nearing closer and closer to top physical condition as the days count down.

The pound-for-pound king has won all 45 of his fight to date - 26 by knockout - and hopes to end his career unbeaten.

However, his desire to end his boxing days with an unblemished record reduces the chances of the US champ taking on the likes of Manny Pacquiao and Amir Khan in the near future.

Would he beat Pacquiao and Khan? Give us your thoughts in the comments below.

Amir Kahn
Manny Pacquiao
Floyd Mayweather