The 41-year-old underwent surgery on her shoulder and only recently returned to racing. She had injured it in a crash while training for the season-opening Albstadt World Cup in Germany in mid-May.
"I'm even a little surprised," said Spitz. "A great healing process made this possible. This is a very special title for me."
Spitz crossed the line to win the German championship in 1:30:14, over a minute ahead of the runner-up Elisabeth Brandau.
Spitz raced a 29er for the first time, which she said helped her feel more confident on the downhills and a bit more upright, thereby lessening the pain in her shoulder. She tried not to take risks on the downhills since her shoulder is still healing.
Her strategy was to race from the front, so she would have time to pick her way on the technical sections and to make up any lost ground on the climbs.
"During the race, I gave little thought to my shoulder," she said. As the race progressed, her victory looked more certain and her only thoughts were on not crashing or having a mechanical.
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Spitz will race her first World Cup of the year in Andorra at the end of the month. She is focusing on the Worlds in late August in South Africa.
