Watch BPI Sports Co-Founder James Grage explain the A-HD /Solid™ testosterone support formula. A-HD/Solid also known as Solid Stack designed to promote testosterone levels and muscularity. You can expect a leaner physique, lower body fat, increased strength and of course balanced testosterone levels. The unique ingredient profile of A-HD/Solid™ is backed by research and is designed to support a healthy anabolic state for longer, more intense workouts.*†