For all the talk about the importance of fitness to Boomers, the big U.S.-based gyms do precious little to attract them. Clubs in big cities like Bally focus strictly on buff 20-somethings in their ads, and adamantly refuse to target the 50+ market, which has the motivation and money to work out. They’re following the age-old marketing adage of the auto industry, to wit: you can sell a young man’s car to an old man, but not the other way around. Now, Associated Press reports, niche gym operators are springing up to serve the 50+ and senior markets. Players include Healthfit, Club 50 and Nifty after Fifty. Some of these outfits are franchises, in case you’re thinking of tapping into the midlife bulge market.