Boston was selected on Thursday as the American candidate city that will bid to host the 2024 Olympics, taking the first strides in a gruelling marathon to bring the Summer Games back to the United States.

Days after the world of athletics was hit by serious doping allegations, the sport has been accused of covering up how it dealt with scores of suspicious blood samples.

The International Olympic Committee has unanimously passed 40 sweeping reforms proposed by president Thomas Bach that will allow the Olympics to be staged in two countries, add new sports and create a new Games television channel.

International Olympic Committee (IOC) boss Thomas Bach has insisted there must be no clash between the Winter Games and the Qatar 2022 World Cup.

France's Renaud Lavillenie and New Zealand's Valerie Adams were named the male and female World Athletes of the Year for 2014.