It was in the future. There were not many people left but those who had survived had it pretty good. I was one of them and at some kind of Olympics. I was thrilled to see athletes have a go at a sport I can describe as a cross of skateboarding and snowboarding. Imagine snowboards with wheels. And no snow as no one alive at the time had ever seen any.
People were apparently competing in two different categories: yellow (easy) and blue (hard). There were poles put in the sand. At least I think it was sand. It was pure white and glistened. Nets were stretched from pole to pole and after every couple of nets there was a platform that could sometimes double as a trampoline but was sometimes just a flat, hard surface and sometimes really slippery.
Competitors had to jump, skip, slip, ride from one platform to the next as fast as possible. With points being added for style and tricks and points being distracted for touching the nets with their hands. Falling meant disqualification.
The lower poles - with the yellow nets - were for mostly teenage riders who couldn't fall more than two meters while the athletes - mostly adults - riding the higher and blue nets could get seriously hurt after a seven meter fall.
I didn't see any elderly people during my time in this future, by the way.
There was loud cheering from some speakers (people watching from home?) as the dozens upon dozens of riders started to go down the parcour simultanously. From right to left.