Humphrey is a Kenyan rugby union player who captained their famous Sevens side during a period of national success. He is also an organic chemist and an Atlas Rugby Champion helping as a role model with boys and girls across Kenya and Africa.

He has also played for the Kenya 15 a side team. He is the older brother of IRB Sevens World Series top try scorer Collins Injera and their younger brother Michael Agevi has also played rugby for the Kenya Sevens.

In 2010 Kayange was awarded the presidential Order of Golden Warriors (OGW) alongside Collins Injera for their performance in the 2008/2009 IRB world series.