The Stress & Form Chart shows the relationship between your training stress and your rest. Every individual workout on your calendar is assigned a Stress Score(*) that represents the physiological cost of that workout, and thereby how fatigued it will make you. This chart uses those stress scores to paint a picture of your training over time, inclusive of both training stress and rest.
It’s important to recognize the thinking about fitness development that this chart represents. Namely that what you are after is not fitness alone, but the state of being simultaneously fit and rested. This combination is referred to as Form, and for many athletes having peak Form at specific points in their season is the overall goal of their training plan.
The Stress & Form Chart describes how the relationship between your training stress and your rest will produce Form. It uses three metrics:
This is a rolling, exponential, one-week average of the stress scores from your workouts. It’s highly analogous to how you experience the intensity and volume of your training day-to-day. The higher your Fatigue, the more work you’ve done in the last week, and in all likelihood, the more tired you are.
This is a rolling, exponential, six-week average of the stress scores from your workouts. It represents how fit you are and thereby your overall potential for having good Form. It is a longer-term look at your training process than Fatigue, and thereby has less to with with “today” and more to do with what the trends in your fitness over time.
The higher your Form the more likely it is that you will perform at a high level on that day. There is no one target value for everyone. Anything from positive single digits up to the mid-twenties could be sufficient, depending on your training.
So, what do these metrics show in practice?
As you develop cumulative training stress over time you are increasingly more fit (rising Fitness numbers), but if you do not rest you are also increasingly more fatigued (rising Fatigue numbers). In this situation you are fit, but too tired to perform well - thereby your Form will be low. Conversely, if you have built up a sufficient degree of fitness (rising Fitness numbers), as you rest (dropping Fatigue numbers) your Form will improve indicating the potential for improved performance.
And, how do I use it?
Watching your Stress & Form Chart over time allows you to apply workouts and insure that you are building fatigue as your Training Plan anticipates, and that you are resting at the correct times to elicit peak Form for target events.
(*) Provided that the workout has recorded data that includes heart rate, power or pace.