Throughout most of the training year the workload should be just great enough to produce stress marked by fatigue and adaptation, but not so high that overtraining results. The level at which overtraining occurs is the “overtraining threshold.” Realize, however, that the overtraining threshold is a moving target. What causes overtraining when fitness is low is easily tolerated when fitness is high. For experienced athletes there actually comes a time when the overtraining threshold is exceeded in order to produce the highest levels of fitness.
As physiological adaptation occurs with improving fitness, the overtraining threshold rises. So the workload must rise along with it if fitness improvement is to continue. Most athletes recognize this phenomenon and allow for it by increasing the number of intervals within a workout, or by extending the length of a workout, or by doing repeats at a greater speed. The problem is that most athletes try to rush the process. But it’s simply not possible to speed up the changes that happen at the cellular level ¾ short of using drugs. The human body adapts to changes in workload slowly and steadily. Each individual athlete has his or her own unique rate of adaptation. The trick is to discover what yours is and then to abide by it when determining training workloads.
How can the overtraining threshold be identified? It’s tough to nail down, in part, because it’s always changing, but also because there are no universal and absolute standards. For example, I can’t say what a certain resting heart rate means for your level of overtraining. That must be determined individually. I’ve found, however, that there are several categories of markers that may predict when you are exceeding your overtraining threshold. They are:
- Fatigue that doesn’t go away with 48 hours of active recovery. Your legs feel tired or there is general body weariness that lingers even after you’ve taken it very easy for two days.
- A loss of control over emotions — evidence of anger, feeling sorry for yourself, moodiness, depression, grumpiness. In short, you’re hard to live with. Your spouse or roommate may be the first to recognize this.
- Performance declines. For example, you’re slower at the same heart rate, or for any given speed, heart rate is high. (Note that a high or low exercise heart rate alone does not indicate overtraining.)
- Self-confidence declines. This may be the best marker, but it’s hard to assess. One way to do it may be found in trying to visualize accomplishing a specific race goal. If it seems out of reach and farfetched, self-confidence may be low.
When any of these markers show up and linger for more than two or three days, there’s a good chance that the overtraining threshold has been exceeded. At this point the workload must be reduced immediately until you are back to normal. Then take time to evaluate what level of workload produced the problem, and make adjustments as you start back.
By learning to recognize and stay below your overtraining threshold while designing your season around your limiters and strengths, you’ll improve race performances both in the short and long term. That’s smart training.