Michael Johnson
Venue: Hayward Field, Eugene, Oregon Dates: 15-24 July
Coverage: Watch live on BBC TV, BBC iPlayer, BBC Sport website and mobile app (UK only)

The time was slower, she finished lower on the podium, but for Dina Asher- Smith this 200m bronze medal probably brought as much satisfaction as her gold from Doha three years ago.

She was getting into a higher level of competition.

She had her best 200m time before she arrived in Eugene. She was the 18th fastest person on the planet.

She knew that Shericka Jackson was in the best shape of her life.

Her strength was getting stronger.

Some people had run faster than she had.

She was a big favorite going into the final.

Dina was able to raise her game and win a medal. Real character was shown by that.

After the race, she said that she had been struggling with the death of her grandmother.

It can be hard to perform at a high level. The public would not know about those things.

It may have been a fear that if you made those personal things public, you would be giving your rivals something to talk about.

Things haven't been the same in a long time. Social media has changed the way we share things.

You can learn more about the person behind the athlete. New challenges for athletes are posed by it. They have to learn how to balance their public image with their personal struggles in order to achieve their athletic goals.

I had personal and emotional issues when I was racing. I kept my grandparents' death a secret.

Things were simpler because it wasn't common to share it.

Noah is a member of the modern generation.

He seems to have found a way to be at his best. He successfully defended his 200m world title in a time of 19.31 seconds. He was the third fastest man in history after going 0.19 seconds faster than before.

The man is on the track. He interacted with the crowd before the race started but also in his celebrations.

It's possible that it affects his competitors. The teenager finished third in the final.

I do not believe they are mind games. Noah likes athletics because it makes him happy.

The same thing happened with Bolt. He once told me that I could never have approached a race like I did. If he had approached that, he would have gotten too nervous.

I think Noah can break Bolt's world record in the next few years. The way he attacked the opening 100 metres and ran the bend was unlike anything we've seen from him before.

My US record of 19.32 seconds was broken by him. I had a quick chat with him after, but I don't think it means much to him.

The focus in the United States is more on world records than on the American record.

The 200m world record was broken by Bolt, and the 400m world record was taken by Wayde van Nierk.

I always believed records to be a target to work towards and strive for, rather than something to hold on to.

Noah is going to look at Bolt's world record in that way.

Maybe it won't be next year. Having already won 200m world gold twice, he might try to double up and combine with the 100m in the future.

With that missing Olympic gold to go for, I would think he would focus on 200m.

That could be a big deal.

Michael Johnson was talking to a person.