Cardio and Talking

Just not sure... today the plan was to power through all the work out.  A peek at the scale had the motivation level up.  It is only Tuesday but there was a little drop (now to keep it off until Sunday weigh in) after the four week stall.  Just as I was getting starting on the treadmill a very nice woman started the machine right along side.  She was nicely dressed, thin  and loaded with magazines and a book.  She began at a light pace which never changed and also started talking.  In a different setting or time she would have been a great person to get to talk with.  The problem, the plan was to keep things at a level where talking would not be at a comfortable level.  I thought the sweat dripping and difficult talking would be a clue as time went on.  Is it rude to not want to be chatty through your workout? How do you nicely let someone know this is not really the time you want to have a conversation?  Keep hoping someone would get on the machine on the other side of her and they might start talking.  In the end got a good workout in.  Feeling pretty sore after three days of good work outs.  Back at it tomorrow.