Career
In his childhood Weißhaidinger competed in gymnastics, but dropped that sport after growing too tall and concentrated on athletics. He also competed in both events at the 2009 World Youth Championships and the 2010 World Junior Championships. In the shot he placed fourth in 2009 and sixth in 2010, while in the discus he went out in qualifying both times.
Weißhaidinger broke the Austrian under-23 shot put record in 2012, throwing 19.22 m.
He was a finalist in both the shot and the discus at the 2013 European U23 Championships, but did not place in the top six in either event. Weißhaidinger first broke 60 metres with the men"s 2 kg discus in 2014, throwing 60.02 m in April and 60.68 m in May.
He was the first Austrian under-23 thrower to exceed 60 metres, breaking Gerhard Mayer"s national under-23 record from 2001. Weißhaidinger competed in the shot at the 2015 European Indoor Championships, but was eliminated in the qualification.
Outdoors, he improved his personal best in the discus several times, reaching 63.13 m in July.
On 1 August, helped by perfect wind conditions and a new technique, he threw 67.24 m in Schwechat, improving his personal best by more than four metres and breaking Gerhard Mayer"s Austrian record of 67.20 m. The mark also exceeded the qualifying standards for the 2015 World Championships and the 2016 Summer Olympics. At the time, it ranked him fourth on the 2015 world list.