
If you can take them try a recovery drink like Rego or Torq as they have protein as well as carbs. When I had gastric flu last November it was the first calories I could consume, I had a recovery drink a day for three days (after the first three days of being ill), not much but better than nothing. I also used Nuun electrolyte tabs in water to get salts in.
If you do race on Saturday be prepared to just feel knackered with legs like pieces of chewed string as your body has just taken a hammering, as long as you manage your expectations for the day and don't try to ride laps at warp speed it should help. Took me quite a few weeks to feel 100% after gastric flu and get a proper appetite back.