This paper presents the validation of a stochastic model of muscle fatigue during static muscle contractions. Forty four laboratory experiments, covering eleven test conditions for two trained subjects, were run in order to estimate fatigue and recovery rates, based on EMG observations. The validation of the model was made by comparing the model predictions to the experimental fatigue time. The validation study supports that the stochastic model of muscle fatigue accurately represents the underlying fatigue process. The study also provides support that the fatigue model can be used as a monitor of individual muscle capabilities.