english: Though muscle cells use up ATP as they  contract repeatedly, they are always making more, so most of the time even heavily fatigued muscles still  have not depleted this energy source.
non_english: Mada mišićne ćelije potroše ATP dok se iznova kontrahuju, uvek ga stvaraju još, pa u većini slučajeva čak i veoma umorni mišići i dalje ne iscrpe ovaj izvor energije.