Why do guys ask girls to work out together at the gym and is there a benefit?

Lots of reasons! Well, three come to mind.

1. Studies show that training with the opposite sex raises a mans testosterone. Bam, better gainz
2. Motivation - what guy doesn't like showing off for a woman at the gym. Come on, you know you do.
3. Getting laid. Just my observations over the years.
   Dont take my word for it all though, get over there and mix up a smoothie at the proshop, AFTER she finishes working out.
   Nobody likes to be interrupted mid-set by some douche asking if they want to work out with you. Male or female.
   E-GO 2018