In 1965, Heger took over as head coach of the Czechoslovakia national basketball team. He won silver at EuroBasket 1967 and bronze at EuroBasket 1969. In 1983, he started as head coach of the Netherlands national basketball team. Heger led the team to the fourth place at EuroBasket 1983, the best ranking of the Netherlands of all-time. From 1984, he coached several clubs from the Eredivisie including Den Bosch, Zaandam and Akrides.