The NOVABLAST™ 4 TR running shoe features a new midsole and outsole geometry that helps produce an energized ride. It's designed with a trail-specific outsole that's functional for running on off-road surfaces. A tongue wing construction in the upper helps improve the fit while reducing tongue movement. This component is reinforced with a supportive heel design to help guide the foot with more control through your gait cycle. FF BLAST™ PLUS ECO cushioning is made with 20% recycled bio-based content. This material helps create softer landings and a more energized toe-off during your training.