Casio’s G-Shock lineup is already packed with tough, workout-ready watches, especially under the G-Shock Move (also known in some regions as G-Shock Squad) family. But if you specifically want a G-Shock with an optical heart rate sensor, the choices are surprisingly narrow right now—limited to the GBD-H2000 and the DW-H5600 series. A new leak suggests that may be about to change, with Casio potentially preparing a fresh square G-Shock that mixes serious fitness tracking with a more premium metal build.
A newly leaked model number, GM-H5600, points to what could be a “best of both worlds” design. The report claims this upcoming watch may effectively combine the fitness-focused tech found in the DW-H5600 with the metal-cased style associated with the GM-5600 line. In other words, it could deliver the modern health and training tools many people want, while adding a lifestyle-friendly metal case that looks and feels more elevated than the typical resin build—without giving up the durability that made the square G-Shock iconic.
Although Casio hasn’t confirmed anything yet and the full spec sheet isn’t known, expectations are that the GM-H5600 would carry over most of the advanced tracking features associated with the DW-H5600. That could mean continuous heart rate monitoring, sleep and workout insights, tools for run tracking and interval training, and recovery-oriented metrics such as Life Log and Nightly Recharge. The leak also suggests blood oxygen measurement may be included as well, giving it a more rounded health-and-fitness toolkit for daily wear.
The “GM” naming is the biggest clue about what makes this model different. In Casio’s usual naming logic, GM models emphasize metal construction. If the GM-H5600 does move to a metal case, it would likely be positioned as a more premium option than the DW-H5600—potentially appealing to buyers who want a fitness watch they can wear to the gym and still feel good about wearing with casual or even smart-casual outfits.
Timing-wise, the leak notes that the GM-H5600 was reportedly registered with multiple Asian certification bodies months ago, suggesting development is already in progress. There’s still no official launch date or price, but a spring or summer 2026 release window is being floated as a reasonable estimate. If the metal build becomes the headline upgrade, it’s also fair to expect a higher price than the DW-H5600.
For now, all details remain unofficial and should be treated as informed speculation until Casio makes an announcement. Still, the idea of a square, metal G-Shock with heart rate tracking and modern wellness features is exactly the kind of update many fans have been waiting for—especially those who want fitness sensors without giving up the classic G-Shock silhouette.
