Walstad has played in four Winter Universiades; playing in the 2011 Winter Universiade, he played third for Markus Høiberg, finishing 7th. The team represented Norway again at the 2013 Winter Universiade, where they improved to a fourth place finish. At the 2015 Winter Universiade, Walstad skipped the University of Oslo rink to a gold medal, defeating Russia's Evgeny Arkhipov in the final. Walstad again skipped Norway at the 2017 Winter Universiade, where he won a bronze medal.