2017 IAAF World Championships - Day Four - London Stadium [Getty Images]

Kenya's Faith Chepngetich Kipyegon celebrates winning the Women's 1500m Final ahead of USA's Jennifer Simpson, South Africa's Caster Semenya and Great Britain's Laura Muir during day four of the 2017 IAAF World Championships at the London Stadium. (Photo by John Walton/PA Images via Getty Images)

PA Images John Walton - PA Images