Just a quick thought

A lot of the time when I see athletes do interval or repeat work, they usually don't run their best until their second or third rep, almost never on their first rep. If this is the case, it is time to revisit your warm up, just getting a sweat going or doing a slow jog may not be the right move. I know everyone is scared of fatiguing the body before the event but maybe a warmup with some higher intensity is needed.