Saturday night in Chorzow, heat three of the women’s 4x100m, and four Ecuadorian sprinters are huddled together in the mixed zone, looking out at the blue track.

Competition records were set in 12 events – eight of which were sprint disciplines – at the South American U23 Championships in Cuenca, Ecuador, which concluded on Sunday (30) after two days of action.

It almost seemed a certainty that USA’s 4x100m team – which included three of the athletes who broke the world record to win Olympic gold in 2012 – would win at the IAAF/BTC World Relays, Bahamas 2015.

Kaylin Whitney became the third US female sprinter in the past decade to win the world junior 200m title and the 16-year-old Florida high school student did it in a commanding way with a wind-assisted 22.82 (2.4m/s).

Great Britain’s Dina Asher-Smith ran 11.23 to take the women’s 100m title in a dominating blocks-to-finish performance.

Rafith Rodriguez and Rosibel Garcia provided the highlights for a strong Colombian team that dominated the athletics events of the 17th Bolivarian Games (Juegos Bolivarianos) that took place in the Peruvian city of Trujillo, and ended after five days of competition on Saturday (30).

Ecuador’s Angela Tenorio highlighted the South American Junior Championships that took place at the ‘Estadio Jaime Zapata’ in Resistencia, Argentina, on 18-20 October.

Sweden’s Irene Ekelund stormed to a 22.92 lifetime best and championship record on the final day of this year’s IAAF World Youth Championships on Sunday (14) to more than make amends for finishing fifth in the 100m final on Thursday.

USA’s Ky Westbrook claimed a surprise 100m victory over the pre-final favourite and team mate Ariana Washington, clocking a fine 11.33 personal best ahead of her compatriot’s 11.40 that got her the silver medal.