What is Training Stress Balance?
Training Stress Balance (TSB) is the difference between your Chronic Training Load (CTL) and Acute Training Load (ATL): TSB = CTL minus ATL. It represents the balance between fitness and fatigue — your "form" on any given day.
A positive TSB means you are relatively fresh — your recent training load (ATL) is lower than your long-term fitness (CTL). A negative TSB means you are carrying fatigue. Deeply negative values (below -30) can indicate overreaching or overtraining risk.
For racing, the target TSB is typically between +15 and +25. This represents the sweet spot where you have shed enough fatigue through tapering while retaining the fitness you built. Getting TSB right on race day is the primary goal of a taper period.