Kenyan long distance runner Bedan Karoki says an Olympic medal in Rio this summer would lead to "a big, big change in my life", as he seeks glory in the 10,000 metres.

SOUNDBITE: (English) Bedan Karoki, 2016 world half marathon silver medallist:

"I started my athletic career when I was in primary school, I think that was the year 2002, up to now. I would say this is my job and actually I have seen it is a good job."

SOUNDBITE: (English) Bedan Karoki, 2016 world half marathon silver medallist:

"Being selected in the Kenya team for the second Olympics I am very happy and I'm working very hard to see whether I'll get a medal. Actually I have been getting some medals in cross country and half marathon, so I know if I get this medal in the Olympics it will be a big, big change in my life."

SOUNDBITE: (English) Bedan Karoki, fifth in 2012 Olympics 10,000m:

"Actually I am training very hard, polishing my speed work. So I am sure if I continue in that way I'm going to finish in the podium."

SOUNDBITE: (English) Bedan Karoki:

"What I can say is doping has been a big problem to our country. So what I can tell the young athletes is to train hard, because hard work pays. Also we are worried because we are being tested every time and now (time and again) removing blood, which is not good. Every time blood is being removed, and we are not happy for that. So what I can say, is to tell those guys who are doping to stop that habit."