What is Chronic Training Load?
Chronic Training Load (CTL) is an exponentially weighted moving average of your daily Training Stress Score (TSS) over 42 days. It represents your accumulated fitness — the training load your body has absorbed and adapted to over roughly the past six weeks.
A higher CTL means you have been consistently training at a higher volume and intensity. CTL rises slowly through consistent training and decays gradually during rest. It is often displayed as the "fitness" line on a Performance Management Chart.
CTL is most useful for planning: it tells you where your fitness stands, how much training load you can likely handle, and whether you are building toward a peak or losing fitness during a break. Safe CTL ramp rates are typically 3 to 7 TSS/day per week, depending on experience level.