PUBLISHED 04/23/2007
The Power of Three
Many runners' conversations begin with "How many runs did you do this week?" and "How many miles did you run?" These questions neglect the importance of intensity--the pace of each workout. The FIRST plan, however, favors intensity over frequency, quality over quantity, fast running over the accumulation of mileage. Why? Because the higher the intensity, the greater the return.
For PR-chasing runners, this translates into the training principle of specificity: If you want to run fast, you have to train fast. But if speed isn't your goal, hard workouts still matter because the benefits of moderate-intensity exercise are magnified with higher-intensity workouts. Your caloric expenditure is greater, which contributes to weight control, and your body's ability to utilize fat increases, which translates into greater endurance. Plus, the single best predictor of longevity is maximal aerobic capacity; and the single best way to improve your aerobic capacity is to train with intensity.
FIRST tailors its intensity to runners with three weekly runs--track repeats, tempo, and the long run. Together they improve the primary predictors of running performance: VO2 max, lactate metabolism, and running economy. That is, speed, the ability to sustain speed, and endurance.
All three workouts improve these variables, but each targets some better than others. Intervals improve speed by increasing VO2 max (the body's ability to produce energy using oxygen), and running economy (the amount of oxygen being consumed at a given speed). Tempo runs, also called lactate-threshold (LT) workouts, teach your body to run faster longer by training it to utilize lactate (a by-product of exercise), instead of letting it build up and shut down the muscles. Tempo runs also build endurance, as, of course, do long runs. The long-run pace in the FIRST program is faster than other programs', so instead of just increasing endurance, you're also improving your running economy.
The three workouts aren't unique to FIRST; what is unique is that these runs are the only ones you do. Because each run targets a specific performance objective, you don't need more miles to reach your peak. You do need time to recover. If you run the day after a track session, for example, you stress the same muscle fibers. Over time, the result is muscular fatigue, not muscular adaptation, and injury instead of training.
But using those same muscle fibers for different activities permits recovery while adding to your total training volume. Swimming hard for 1500 meters, biking a quality 20 miles, or doing 30 to 60 minutes of other strenuous aerobic activities allows your running muscles to recharge while you reap cardiorespiratory and muscular benefits. So you get the advantages associated with running more miles without the pounding and repeated stress that can lead to fatigue and injury.
Cross-training not only enhances fitness, but it also adds variety and flexibility to your week. If the roads are icy, you can swim; if the pool is closed, you can cycle. This helps avoid boredom and burnout, and the variety enhances your desire to train.
