Diesel Gym, North Brunswick

Long after other gym owners have locked their doors and crooned bedtime lullabies to their weight machines, Diesel Gym owners Derek Miller and Jonathan Tuchmatulin keep their doors open for late-night and early-morning exercisers. On weekdays, the fitness center is open 24 hours a day, and even on weekends, it's open 7 a.m. until 8 p.m. So whenever exercise inspiration strikes, members can build stronger, more defined physiques with the gym's classic iron-plate weight machines.