OUR request last week for suitable suggestions for personal trainer Bob Pike's forthcoming book on exercise really got some of you good folk in a sweat. The faxes didn't stop coming. And now Pike will be left with the task of burning mental calories from among the offerings we have passed on to him. Two of our early entrants, Sally Sank and Geraldine Murphy, appeared to get more and more creative as the week went along. But here we owe Sally an apology. For in our earlier piece we had her saying that, should her entry be chosen as the title, she would not be taking up an offer of a copy of the book or a course of personal instructions from Pike as she was ''already terribly fit with a very possessive husband''. Shot back Sally, who runs Essensuals, the aromatherapy shop in Central: ''Please, please, I am single and I need help. Mentally I'm okay, but I could do with some assistance on the physical side.'' Meanwhile, Geraldine responded: ''My heart SANK for it was my quote.'' A final message came in for Pike. It read: ''Take A Hike, Pike.'' A good time to bring the competition to a close.