Anytime Fitness (pictured), 24/7 Fitness, Jetts

Workout: Fully-equipped gyms
Weekday Hours: 24-hour
Location: Branches across the city.
 

Aspire

Workout: Crossfit and HIIT
Weekday Hours: 6am-9pm
Location: 8/F, Metropolis Bldg., 725 Sukhumvit Rd.
 

BASE

Workout: HIIT and strength-based training
Weekday Hours: 6:30am-9pm
Location: Three locations, try Noble Remix Building 2, Sukhumvit Soi 36.
 

Tribe

Workout: Spinning, barre, yoga
Weekday Hours: 7am-10pm
Location: 973 President Tower Phloen Chit Rd.

Physique 57

Workout: Barre
Weekday Hours: 7am-8:30pm 
Location: Three locations, try 4/F Erawan Bldg., 494 Phloen Chit Rd.

Credit: www.facebook.com/VirginActiveThailand

Virgin Active

Workout: Fully-equipped gym
Weekday Hours: 6am-10pm 
Location: Multiple branches, try Empire Tower, 102 Naradhiwat Rajanagarindra Rd.