They're two of the brightest stars in Irish and Leinster rugby, and they're brothers!
And now, Ross and Harry Byrne are going to race against each other, and it's all for a good cause.
The two are taking part in a special Run @ Home for the Simon Community. The lads will be racing the route of the Six Nations against each other, and they want you to join their team.
Speaking to Dermot and Dave, the lads spoke about sibling rivalry, playing to an empty stadium and mental health in sport.
You can catch the chat in full by clicking play above.