They have utility in each, depending on context and application. As noted, it worked for Mills to help keep him in the race in Tokyo. For Mark Wetmore's CU harriers, given their typical racing strategy they need remember “patience” for the first couple of miles (especially at D1 CC Nationals) while so many others around them are blazing out of the gates over their heads. I know that when I race at 800m, I have had to key on “aggressive start” — which might not hurt for races of longer distances, either. Unless and until one has perfected one's training and racing strategies, using a mantra to key on the focus for the run or race can be helpful.