Although the headphone market continues to burgeon with new models, it can be surprisingly tough to find a decent, fitness-friendly pair. A few companies, such as Sennheiser, have stepped up to the plate with sport-branded earphones, which feature design attributes meant to keep them secured on the head during activity. Now, we can add Sony to the list. The company has released an impressive array of Active Headphones, the $100 MDR-AS100W among them. These mostly well-designed earphones are a good option for the gym, with an adjustable over-the-head band that should work for just about any person looking for a secure fit. However, this set is not as comfortable, compact, or inexpensive as the fabulous MDR-AS50G.