I teach students that they should have a very good idea on race day their planned paces and exertion levels. There should be no real surprises. Each athlete should race THEIR fitness and not try to reach some higher plane they haven't yet achieved in training. If the athlete had setbacks in training but had hoped to attain a certain time on the next race, racing harder than recent tests indicate will probably not get that personal record (pr). More often than not, the higher pacing will cause the athlete to ultimately underperform. Racing "within one's self" will bring the best results.
Athletes should have frequent markers and tests leading up to their big race. I like to do a 500 yard/meter swim time trial every week and a 1 or 2k swim tt about every 8 weeks. A 20:00 wattage test is great every 2-3 months or so but a 5 minute test also comes in handy. A 5k run test is adequate for shorter racing but a 10 miler or half marathon is more telling for longer triathlons. Three 1 mile threshold repeats on the track serve well to assess run fitness, making sure the mile repeats stay within a few seconds of each other. These smaller, more frequent tests should show the athlete's upward progress and allow the athlete to feel what it's like to race hard.
One should do portions of their target race as race "rehearsals". Be prepared for this in advance. Go to the pool, with your bike in the car, your running shoes, along with all the supplies you will need for the session. Swim some portion or all of your intended race, bike anywhere from 1.5-5 hours, then run 30-45 minutes. This obviously depends on race distance. You should hit your race pace or just a bit above for portions of the rehearsal. Wear your race day clothing to include a wetsuit. See how your nutrition works out. Do this about 6-8 weeks out from your "A" race as this will give you an idea of the stress that will be involved on race day. Try to use the race course for your simulation. This rehearsal shows the athlete realistic nutrition and pacing for the "A" race.
On race day, be prepared to hit those paces. The triathlete's biggest mental struggle is maintaining those predetermined race paces when the body starts to rebel late in the bike and run. Get used to the idea that the end of the run is just going to feel hard!
"Again, racing for me was about energy management." - Frank Shorter
"The five S's of sports training are: Stamina, Speed, Strength, Skill and Spirit;
but the greatest of these is Spirit." - Ken Doherty
"When you get to the end of your rope, tie a knot and hang on." -Theodore Roosevelt
"Many of life's failures are people who did not realize how close they were to success when they gave up.” - Pre