The 49-year-old wing – who is still the record try scorer for Wales – didn’t think he’d achieve his ambitions in the sport when he was young, so turned to football and gymnastics, which he thinks ultimately helped with his rugby skills.
He told Rugby World magazine: “I was quite nippy and quick but I was so small in comprehensive school that they never used to pick me for the rugby team.
“And if I couldn’t get into the school team, how was I ever going to play for Wales?
“I fell in love with [gymnastics]. I trained every day – every lunchtime and sometimes after school as well.
“I look back and think how big a part the gymnastics played in my power-to-weight ratio.
“It enabled me to break tackles and compete with the big, strong wingers who I was giving away 20 kilos to.”
Although Shane made his Wales debut in the 2000 Six Nations, around a year after becoming a full-time professional, he was furious when new manager Steve Hansen dropped him because of his size.
He recalled: “He didn’t get me at the start. He dropped me from the team pretty early on when he was looking for 16st wingers.
“I was very angry at the time and I thought it was unjustified.”
However, Shane ultimately thinks being dropped was good for his game.
He said: “I was out of the team for 18 months but that 18 months was probably the period that made me as a professional rugby player.
“I worked on my weaknesses. I worked on my strengths. I became fitter, faster, stronger, and I came back a better player.”