Question

fatigueness of striated muscles fibre ​

Answer 1

they get easily tired but not cardiac muscle

Answer 2

It was once believed that lactic acid build-up was the cause of muscle fatigue. ... Though the impact of lactic acid on performance is now uncertain, it may assist or hinder muscle fatigue. Produced as a by-product of fermentation, lactic acid can increase intracellular acidity of muscles.