56th National Inter-State Senior Athletics Championships, a qualifying event for the Rio Olympics, will begin in Hyderabad today. As many as 744 athletes, including 264 women from 26 states will take part in the five-day event. So far, 21 athletes have qualified for the Rio Olympic Games besides the women's 4x400m relay squad. A Sri Lankan relay team will also take part in the event in its bid to attain the Rio qualification standard. This is the fourth time that senior Nationals have returned to Hyderabad.