An early winner is a late loser.
Needless to say, it is extremely important to race within your fitness and ability. To do this, you need to be smart. Pick a pace you can realistically sustain over the distance you are racing or you'll be setting yourself up for an unpleasant day.
Despite having a plan and contrary to what you may think, many athletes go out way too hard on the bike (or run) and find themselves with little to no energy to finish the race the way they expected. You may laugh, but when your adrenaline is pumping and you're well tapered it's very easy to do. Don't be this person. Even if you think it's your day, save whatever extra energy you may have for the final 10K of the run.
It is always best to start your day going out easy. Then once you find you're easy, go easier. This strategy will pay dividends as the day progresses.
Not only is it best to go out easy and finish strong, but it is also smart to have a pacing strategy. This is especially important for iron-distance races, but also applies to shorter races. I know what you're thinking: what the heck is a pacing strategy? Well, a pacing strategy is NOT going out at your goal race pace hoping you're able to sustain or just hold on. Instead, if you're goal pace is to average 9 minutes per mile and finish the marathon with a sub 4 hour time, start by running your first few miles at around a 10 minute per mile pace.
I know this sounds crazy, but it works. This way, you'll allow your heart rate to slowly climb rather than spike. This way you can find your rhythm on your own terms. As you start to clip off the miles, slowly start to increase your pace until eventually you'll be finishing your race faster than your average goal pace, looking and feeling like a champ.
Remember, negative splits (where the second half is faster than the first half) are far cooler then blowing up and dragging yourself to the finish line. Running 12-minute miles (if you have to) is far better than walking 18-minute miles on the run. Do the math!
Process vs. Outcome Oriented
Everyone has different goals when it comes to triathlon. However, whether you're looking to set a new PR or just finish your first iron-distance triathlon in less than 17 hours, most athletes have some kind of finish time stuck in their head. This is very normal and it's ok to set goals for yourself, however that number should NOT be your focus on race day.
Finish times and various race splits are an outcome-oriented mindset. What happens if race day is crazy hot, rainy or there are brutal head winds? That time you have stuck in your head will likely not come to fruition. The point is, it is far better to take a process-oriented approach. Make a list and "check the boxes" as the day unfolds. A process-oriented approach means you are in control, no matter what. As a result, you will not lose focus when things you cannot control go wrong.
You can easily apply this approach on race day by making a reoccurring list for you to continually check the boxes while your swimming, biking and running. For example, coach Matt Dixon has his athletes while on the bike "check in" with their form. "How's my cadence? How are my shoulders? Am I relaxed?" Then fueling: "How am I feeling? What's my energy like? How's my stomach feeling? Do I need to stay off calories for a bit?" And finally, pacing: "How's my body feeling? Am I at the right power? Am I working hard enough (or too hard)?"
Once you create your own checklist you will want to "check in" with yourself every 10 to 15 minutes. This will help time pass, keep you focused and ultimately lead to the race performance you were hoping for...all while NOT thinking about your time or splits.