If the fastest swimming, cycling, and running you do is during a race, you're not training right. Every triathlete's training should include speed work, or efforts that exceed race intensity.
Speed work not only changes your perception of race intensity, making it feel more comfortable, but it also enhances fitness in ways that slower training does not.
There are right and wrong ways to incorporate speed work into the training process. Doing speed work the right way is not difficult. All you need to do is copy how professional triathletes go about it. That's not to say you should try to go as fast as they do.
It all comes down to obeying these three simple rules.
Rule No. 1: Speed Train Year Round
The term "periodization" refers to the practice of dividing the training process into phases and assigning a distinct fitness objective to each.
The first phase, known as the base phase, concentrates on building general aerobic fitness and endurance through large and increasing amounts of low-intensity training. Speed work is excluded from this phase because maximizing overall training volume is easier when intensity is kept low.
These days most elite triathletes include a small amount of high-intensity swimming, cycling, and running in the base phase, and you should too. The reason is that when speed work is eliminated from training, the athlete loses the dimension of fitness that comes from speed work, making it harder to get back later.
Just one small dose of high-intensity swimming, cycling, and running per week during the base phase will help you to avoid falling into this all-too-common hole. Try doing short efforts at or close to maximum intensity, such as 8 x 25-yard sprints in the pool and 8 x 20 seconds of uphill on the bike or the run.
Rule No. 2: Keep Your Speed Training Volume Low
After the base phase of training, the peak phase begins. During this period, which should start 6 to 12 weeks before race day, you'll want to increase your volume of speed work while keeping your overall training volume steady. At this phase of training, speed work should account for no more than 10 percent of your total training volume.
Again, let the pros be your guide. In 2012, I?igo Mujika of the University of Basque Country monitored the training of elite triathlete Ainhoa Murua as she prepared for the London Olympics, where she placed seventh. He found that she spent 10 percent of her total swim training time, 2 percent of her cycling time, and 7 percent of her running time at high intensity. These numbers are normal for elite triathletes and they should be the norm for you too.