Steiner was a Slovak
Jewish, and was a member of Jewish sport clubs in
interwar Czechoslovakia. He competed at 19 years of age with the
Czechoslovakia men's national water polo team in the 1927
European Water Polo Championship in
Bologna, Italy, in which they came in 7th. Steiner competed in the
1928 Summer Olympics in Amsterdam, the Netherlands, coming in 9th with the Czechoslovakia men's national water polo team in
water polo at the Games. He also competed in swimming, and won a
bronze medal at the
1931 European Aquatics Championships in Paris in the
100 m freestyle with the Czechoslovakia men's national swimming team. Steiner competed in swimming at the
1932 Maccabiah Games in
Mandatory Palestine, the first
Maccabiah Games, and won three
gold medals. He won the 100m freestyle (breaking the record from Czechoslovakia), the 3x100m medley relay, and the 4x200m medley relay. There, Steiner won two gold medals in swimming, in the 100m freestyle and in the 4x200m freestyle relay. ==Honours==