i personally think that more women utilize the benefits of personal trainers for two reasons...
1. Men are generally too proud and too embarrassed to be escorted around a gym and monitored while exercising. Its pretty much a pride issue.
2. Generally, women 20-30 yrsold that have a personal trainer are married, havent had children or have had one baby, and have a man that can pay the bills... or, they are working women that are unmarried and can pay the bills themselves... most, but not all, women that are fulltime mothers or mothers with careers, dont have time for personal trainers.
Just my .02