Canelo Alvarez isn't wasting any time getting his body ready for Gennady Golovkin

The boxing superstar showed off his physique at the end of a workout this week -- and shocker, dude looks good.

Of course, Canelo and GGG are set to throw down in September in what boxing experts are saying could be the best fight of the year.

After that light sparring session with Julio Cesar Chavez Jr. last weekend ... it's probably a good idea for Canelo to find a way to break a sweat.