- Nike gives the upper several modifications in the 4th ride of the Relentless. A notable change is the removal of the thick, stitched synthetic overlay on the forefoot. The overlay in the toe box is not as thick as before also. These modifications give the shoe more room and volume to enhance comfort for training sessions.
- Another significant change is the use of a stitched overlay just beneath the collar on the medial side that extends to the heel. It helps with heel stability. On this stitched overlay, the Nike logo is fused on. The lateral side of the collar shows printed overlays to give the upper a more forgiving feel.
- The Relentless 4 has a new engineered mesh for better support minus the stitched most of the stitched overlays.
The fit of the Nike Air Relentless 4 is classic for a trainer. It screams average from the heel to the forefoot. As such, it can be a good fit for those with narrow to slightly wider feet. The small difference between this model and the previous edition is the more relaxed upper and a little more room in the forefoot. Medium is the available width of the shoe. Sizing is spot on in the Relentless 4.
The outsole of this cheap running shoe is made of blown rubber in the forefoot and BRS 1000 carbon rubber in the heel area. Nike utilizes deep and wide flex grooves in the Relentless 4 to bring sole flexibility. Numerous square lugs enhance grip in this shoe.
Nike’s basic compression molded EVA in the Phylon runs the length of the shoe for soft and responsive cushioning. The full-length design helps with the transition from landing to take-off. Beneath this foam in the heel is a moderately thick Air unit for added cushioning and shock-absorption.
A new engineered mesh keeps the shoe as breathable as always, but ramps up the support without using too many overlays. The heel and tongue are plush with a very soft interior lining. A well-cushioned insole helps with the cushioning and fit of this shoe. The same in-shoe feel is also felt in the Nike Relentless 6.