How did the swimmer in the video prepare for the energy demands he was about to place on his body? ?

There are a couple of things that the swimmer in the video did in order to prepare for the energy demands he was about to place on his body:
1. he gained 16 pounds of body fat in order to have his body ready for that ordeal
2. he prepared his mind mentally for what was about to happen
3. he went through a lot of physical training

You get 6 for mechanical