Glossary · Metrics
Training stress balance (TSB)
Training stress balance (TSB) is chronic training load minus acute training load — fitness minus fatigue. Often labelled 'form', it shows whether you are currently building fatigue (negative) or fresh (positive).
How to read TSB
During a build, TSB is normally negative: you are training more than you have recently absorbed. A deeply negative TSB for a long time can mean too much load. During a taper, fatigue drops faster than fitness, so TSB climbs.
Using it to time a race
Many athletes aim to arrive at an important race with TSB clearly positive, having let fatigue clear over a taper of one to three weeks. The right number is individual — compare with how you felt at past races rather than chasing a target figure.