Runners tend to be a motivated lot, always compelled to do more and do it faster. Yet this desire to push our limits can send us over the edge. When our efforts to run faster leave us sidelined with injury or as flat as Frank Shorter's race-day Coca-Cola, there's a good chance that we've gone too far. The trouble is, we sometimes don't know the difference between a great workout and an overdone disaster until a day or two later, and then it's too late. Sometimes we don't know until a month goes by and we have a horrible race! Further complicating things is that each athlete is different in how he or she responds to difficult workouts. Despite the complexity, however, here are some basic rules to ensure that you're working hard enough to get the desired training effect—without going over the cliff.
Rule 1: Train to Race
One evening during high-school cross-country practice, I was feeling feisty. Instead of running in the middle of the pack for the last interval, I launched into the lead and finished in an all-out sprint. But there was no pat on the back for winning the workout. Nope. Coach admonished me—"Hey, we train to race. We don't race to train!" That aphorism is the gauge that can successfully monitor intensity: If the end of a workout feels like the end of a race, you've pushed too hard.
Rule 2: Avoid the Time Slide
If your interval times are getting slower with the same or increased perceived effort, you're either starting too fast, not giving yourself enough recovery, or both. Run at a pace you can maintain for the duration. If you can run slightly faster on the final interval, you've likely worked within the proper training zone.
Rule 3: Know When to Say When
Sometimes it's good to quit while the quitting is good. I advise my runners to end the workout feeling like they could run one more interval at the given pace. This requires an honest evaluation by the athlete. Most runners want to continue hammering away until the time slide occurs, but by then, you've gone too far.
Rule 4: It's Better to Be Underdone Than Overcooked
You can flout these rules once or twice without penalty. But my experience has been that when athletes are constantly driven into a lactic acid–drenched, anaerobic funk at the end of the workout, they will peak quickly then flame out. At that point, only a complete break or an extended period of aerobic base training will bring them back.next race.