What is Acute Training Load?
Acute Training Load (ATL) is an exponentially weighted moving average of your daily Training Stress Score (TSS) over 7 days. It represents your short-term fatigue — how much training stress you have accumulated in the past week.
ATL responds quickly to changes in training load. A hard training block drives ATL up rapidly, while rest days bring it down. It is displayed as the "fatigue" line on a Performance Management Chart.
ATL on its own tells you how tired you are right now. Combined with CTL to form Training Stress Balance (TSB = CTL minus ATL), it reveals whether you are fresh enough to race or need more recovery. When ATL is much higher than CTL, you are in a state of significant fatigue.