It is generally recommended to wait at least 120 minutes after a meal before running. Some people say they are fine with 90 minutes, others go as low as 60 minutes. Test it during your training sessions, none of us has the same stomach.

But when the race day comes, no risks and experiments. If you head out too soon, your meal may not be properly digested which increases the risks of bloating and abdominal cramps. Not nice!