Chris BROWN BAH
Finishing so fast, oh no, that wasn't planned! I just wanted to set myself in a good position for the next round. Hopefully I will be able to run it like I did this one. The conditions are good for running and this results means I'm in shape.

Jeremy WARINER USA
I feel good, I am fine - of course it is the World Championships. I shut it down at 250 metres. The weather conditions here are nothing to me, I train like this every day. The track is good, but I do not want to talk about the world record now.

Alleyne FRANCIQUE GRN
I just wanted to win to get a good lane for the semi-final. I had a slow start this season. This is the first year I didn't run indoors, so I took off late. But now, I'm back into my rhythm and ready to go.

LaShawn MERRITT USA
I ran faster than I was supposed to do, it should have been a 45, but now it is a 44.78 result. The main focus was on winning the race, not on qualifying with a second or third place. In the final, I am going to be in the battle for the gold medal - not only in the battle for the silver and bronze medal!

Johan WISSMAN SWE
It was a perfect race. My aim was to get out fast in the first 200m and control in the second half. I knew the race would be settled between LaShawn and myself and in the last 200m I actually felt pretty easy. That was a fast race but I'm pretty sure I have still more to give.

Gary KIKAYA COD
I've been cautious not to waste too much energy in this round. I've run a lot this season but after the Rome Golden League mid-July, I stopped competing to get back and train in the USA. That was part of the plan to get a better result than in Paris 2003 and Helsinki 2005. The world championships are my major focus this year and I want to finish in the top 3.

Tyler CHRISTOPHER CAN
You need to have good climate controlling, my team was trying to keep me cool. In the hot weather many things are different, the warm-up is shorter for example. But it felt good, the semifinals are always very tough. I spent about 85 percent today.

Nery BRENES CRC
True, I bettered my national record by one second. That is all due to hard training back at home in the Limon  City. I'm doing athletics for 8 years and specially the 400 m in last two years. Now the space opened for me to attack more here.