The pilot reported that he fueled the airplane to maximum gross weight to feel the aircraft’s flight characteristics while practicing maneuvers. After practicing some stalls and slow flight, he approached the airport to land. He said he flew a slightly higher approach speed in consideration of the increased weight. The pilot stated that the windsock was hanging down with no indication of a crosswind during his approach. He made a normal landing that was true and straight, but had a slightly longer than normal roll out. As excess speed bled off, the left wing started to rise. The pilot applied left aileron and left rudder to correct the problem. He looked up and realized he was veering off the runway to the right. He applied braking but departed the asphalt onto very soft sand/dirt at approximately 25 knots. The aircraft nosed over. The airplane’s vertical stabilizer and rudder were bent and wrinkled; the left wing struts were bent and the right upper wing root was buckled. The nearest weather reporting facility, located 17 nautical miles to the east of the accident site, was recording calm winds at the time of the accident.