LIMA, Peru — Team USATF, led by Olympians John Nunn, Maria Michta-Coffey and Miranda Melville, will compete this weekend at the Pan American Race Walk Cup, held in Lima, Peru on Saturday and Sunday, May 13-14. The Pan American Race Walk Cup is the first international championship of the summer for Team USATF, who will complete 2017 global competition in London at the IAAF World Championships.