At about 1635 Eastern time, the airplane was substantially damaged during a series of touch-and-go landings. The sport pilot was not injured. Visual conditions prevailed. The pilot later stated a “gust of wind” made the airplane feel as though it was “on marbles.” The pilot attempted to control the airplane and maintain runway alignment by utilizing aileron and rudder inputs, but when the “gust of wind” subsided, the airplane immediately went towards the edge of the runway. The airplane departed the left side of the runway, collapsing the nose gear. The propeller dug into the ground, and the airplane nosed over, coming to rest inverted in the grass area adjacent to the runway. The firewall, and cabin area exhibited no sign of damage, and the seat belts, seats, and windows were intact. An automated weather observation included variable winds at six knots, visibility 10 miles, clear sky, temperature 25 degrees Celsius (C) and an altimeter of 30.12 inches.