ASICS S4 25.5cm Approximately 50km of running distance I think a pace of 4:30 to 5:30 per kilometer is a comfortable zone. I ran a half marathon in 1 hour and 45 minutes, and it was comfortable. Please read the profile for safety. From the website: ◇ For runners who want to break the sub-4 hour barrier and aim for even greater heights. ◇ A model that achieves the four "S"s: Speed / Stability / Safety / Sub4. It uses "FF BLAST TURBO," the same material as the METASPEED SERIES, in the upper part of the midsole. This shoe features a full-length carbon plate. By widening the ground contact area, it supports stable running. It pursues a balance of responsiveness and stability, providing a ride feel suitable for runners aiming for sub-4 hours.