Indoor pool and spa was OP's comment.... why the quality of LA sports club keeps coming up in thread i'm not sure. Rather have a pool for hotel guests and condo owners than health club's pool that hotel guests can access.
The gym of the Four Seasons, the Sports Club LA, is one of the best in the country. The group classes are excellent, free, and diverse. Their indoor pool was renovated not too long ago. The place is alive.
The St. Regis gym has good equipment but is small and always empty. The pool and spa, likewise, are always deserted. Based on the OP's request I think he'd far prefer the service and amenities of the Four Seasons (it usually costs a bit more but is worth it!)