Wal-Mart, Target and other big-box retailers have spelt doom for a good many middle market grocery stores. Indeed, according to a recent Retail Forward study (quoted in Business 2.0 July 2005) more than 10,000 of such medium sized supermarkets have closed in the past decade. You know the ones – those big-windowed, strip mall stalwarts that are often convenient, but don’t have the great prices at Wal-Mart, the cachet of a Target, or the choices at Lowes, Home Depot, PetSmart or Staples. High-growth fitness company 24 Hour Fitness, the world’s largest privately owned workout chain has found that the empty supermarket spaces make perfect locations for gyms.They are not too fussy to remodel (costs $65 per foot as opposed to $105 for a new build), are in great locations for the in-and-out traffic they seek and best of all have ample and convenient parking. And even more of a second-order effect takes place when the gym moves in. While the local hardware store may shut down, chiropractors, vitamin stores and other suppliers of health related gear move right in. A terrific example of taking advantage of a change sweeping an entire segment.