How do I prepare for a big race day?

If you have multiple races to time on a single day, one choice is to create a group for each race, and then just tap New watches for all at the bottom of the group when it’s time for their race. Watches will offer to either add this group to the Current Race or create a new Race for this group. Alternatively, you could create the actual watches, and then use the ability to reload a race: While viewing the race in History, tap on the title of the race and then hit Make Current Race. Note that you could even leave watches running on the existing race without affecting their timing. Later just Make Current Race again to see the current times. You can even just slide the title of the race left or right to easily switch between recent races.