Hi @Bread_Pudding 

Thanks for posting!   Are you asking about the Pilates symbol we use on Strava, shown here?

That symbol is representing a Reformer, a machine invented by Joseph Pilates.  Although Pilates can be done on a mat, many pilates studios offer the option to use the Reformer.  

Sorry for any confusion over the symbol.  Are you a Pilates fan?  I've tried it a couple of times - it is tough!