Training Stress Score (TSS)

Training Stress Score (TSS) indicates the extent to which a workout stresses the body. It was developed by TrainingPeaks and considers both workout duration and intensity using either Functional Threshold Power (FTP) or heart rate threshold for the athlete. A score of 100 represents a good hour of exercise. The score enables athletes to determine the intensity of a workout and organize their workouts to balance effort and recovery to avoid overtraining. Trainers use TSS to establish training schedules, monitor improvement, and adjust workout intensity as necessary. A higher TSS generally represents more stress, but it also depends on context: a 200 TSS session of an easy ride differs from a 200 TSS session of a hard workout. Monitoring weekly TSS assists in tracking loads and performance trends.