Representing more than 40 nations, nearly 2000 age group athletes pushed themselves to the limits in search of ITU Age Group Sprint World Championship titles on Thursday.

The 2015 ITU World Triathlon Series Grand Final Chicago officially kicked off Thursday morning with the under23 men’s World Champion being crowned.

The 2015 World Triathlon Series has been fast and historical, and as the Chicago Grand Final gets underway with the paratriathlon and elite races on Friday and Saturday, the Series finale will most likely be one that the triathlon world will never forget.

The ITU Aquathlon World Championships kicked off a week of action at the ITU World Triathlon Grand Final Chicago on Wednesday with elite, paratriathlon, junior, U23 and age groupers racing over a 750m swim and 5km run.

In this special edition we preview the 2015 ITU World Triathlon Grand Final Chicago, and also look back on some highlights of the season so far, brought to you by Columbia Threadneedle.

The race for the men's elite World Championship title is one of the closest to be contested since the start of the ITU World Triathlon Series, with only 530 points separating the top four men in the Columbia Threadneedle Rankings.

The women's ITU World Championship title will be decided in a heated battle on Friday at the ITU World Triathlon Grand Final Chicago with only 300 points separating the first two women - both Americans.

All eyes will be fixated on the world of triathlon this week as the 2015 ITU World Triathlon Grand Final Chicago swings into action.

The men’s and women’s Under23 start lists are overflowing with talent that have already been making headlines amongst the elites this year.

The world of paratriathlon has been more exciting than ever, with just under a year to go until the sport makes its debut in the 2016 Rio de Janeiro Paralympic Games.