HRE wrote:
There was an Irishman called John Lenihan who won the World Mountain Racing Championship and was a very good road racer at distances below the marathon. He liked to do a session of 6 x 400 on the day before a race. He thought doing a little fast running the day before a race made him sharper for the race. I always felt sort of awkward early in a race if I took it too easy on the day before a race. You're not going to lose energy in something that short unless you're flogging yourself.
"John Lenihan, who was World Mountain Running champ and a 1:01 or 1:02 half marathoner, did exactly what your coach has his kids doing. He just felt like doing a little bit of faster running on the day before the race left him feeling sharper than not doing it."
You don't have to repeat the same thing every five years.