Mamalos has participated in four consecutive Summer Paralympics. He was first in the Rio DeJaneiro 2016 Paralympics in Men's 107 kg, silver medalist in the 2008 Paralympics in Men's 82.5 kg and bronze medalist in the 2012 Summer Paralympics in Men's 90 kg. In his first Paralympic Games (Athens, 2004) he took the sixth place in Men's 90 kg.