Most Common Obstacles I hear to working out:

"I want to work out but I do not really know how to.  I have no idea how to use gym equipment, and the gym is a bit intimidating and uncomfortable.  Besides, I am not really comfortable working out in front of strangers.  The gym is just not my style"
 
"After having a baby my life has drastically changed.  The logistics of a gym do not work for me, and this baby weight is just not coming off.   Being out of shape makes me tired, irritable and keeps me from enjoying my life and quality time with my family"
 
"I have always struggled with staying fit/exercising.  Fad diets, rollercoaster weight gain/loss, my inability to stick with any program have always been my downfall.  You name it, I have tried it and can't seem to get to the next level"
 
"I work 50hrs+/week and on top of that, take the kids to soccer, baseball, basketball and tennis practice.  I can't even think about finding the time to make a trip to the gym"
 
"I have never been the athletic type.  In fact, I hate working out.  If feels awkward and uncomfortable to me and I need more privacy when exercising"
 
"I need someone to motivate me.  I am the one who will stop before the finish line or do one less set of pushups than I should.  I need someone to hold me accountable for my fitness and be with me the whole time"