Allamand, who started for La Plagne Savoie, debuted in mid-December 1985 at the home Tignes in the World Cup . He started in the disciplines of acro, moguls and combined. In January 1998, he reached the podium for the first time in Breckenridge , USA , before celebrating his first World Cup victory in Mount Gabriel , Canada around two years later . With further strong results, Allamand was at the end of the 1989/90 season both second in the combined and Moguls classification as well as in the overall World Cup. At the 1992 Winter Olympics in Albertville , Allamand was part of a strong French freestyler delegation. In the Moguls' competition, which was held for the first time, he won the silver medal behind compatriot Edgar Grospiron , who was already considered the favorite in advance. His turning technique in particular helped Allamand achieve this success.
He completed his last international competitions as part of the 1994 Winter Olympics in Lillehammer , where he once again proved his class with sixth place in the Moguls competition. After the games, Allamand announced his retirement. A cruciate ligament injury from 1990 was listed as a co-cause.
After his career, Allamand opened, among other things, a sporting goods store in the Olympic village of La Plagne .