Training Stress Balance (TSB) Calculator

How to calculate Training Stress Balance?

TSB measures the relationship between chronic fitness and acute fatigue to predict performance readiness.

Formula: TSB = Chronic Training Load (CTL) - Acute Training Load (ATL)

Using the TSB calculator: an athlete example

Consider a cyclist preparing for a weekend race.

Step-by-step calculation:

• Athlete has a steady CTL of 80 (strong fitness base).
• Their hard training week leads to an ATL of 110.
• TSB = 80 - 110 = -30 (Deep fatigue).
• Athlete rests for 3 days; ATL drops to 60.
• New TSB = 80 - 60 = +20 (Fresh and ready to race).

Frequently Asked Questions

What is a good TSB for race day?

Most athletes perform best with a TSB between +5 and +25, often called the Freshness window.

Why is my TSB deeply negative?

A score below -30 usually follows a heavy training block and suggests a high risk of injury if recovery is not prioritized.

Can I stay in the positive zone forever?

No. Sustained positive TSB often indicates detraining and a loss of fitness over time.