Product Code: 100256256. The Reebok Workout Plus Unisex Trainers in Grey and Chalk are the quietest colourway in the range. Product Colour: Grey And Chalk. The Workout Plus was introduced in 1987 as a dedicated fitness shoe built around two ideas: a full-grain leather upper that would hold its shape under training load and an H-strap midfoot system that provided a quality of lockdown no standard lace-up design could match.