Dan Roan

Walk around London Stadium, as I did earlier this week, with final preparations being made for athletics' World Championships, and it is impossible not to be taken back to that heady summer five years ago, when track and field - the Olympic movement's flagship sport - provided the most iconic moments of an unforgettable Games.

When the action gets under way on Friday and the world's finest athletes go head to head, London 2017 will of course evoke memories of the London 2012 Olympics, which for many back then, seemed like the best of times for the sport.

Eleven sport governing bodies are demanding an overhaul of the way Britain invests in the pursuit of Olympic and Paralympic medals.

In an unprecedented challenge to elite performance funding agency UK Sport, the group have joined forces to call for an urgent review of what they call "a two-class system that runs counter to Olympic ideals".

England's Under-20 World Cup winners have been a revelation, sparking a fresh debate on youth development.

A 1-0 win over Venezuela in Sunday's final in South Korea gave England their biggest international title since 1966.

Back in September 2013 I interviewed an emotional Thomas Bach in Buenos Aires a few minutes after the German had become the most powerful man in sport.

The newly elected International Olympic Committee (IOC) president confidently told me that after a successful reign by his predecessor Jacques Rogge, the Olympic movement needed mere evolution.

The World Anti-Doping Agency (Wada) says it still has "full confidence" in a report into Russian doping despite "discrepancies" in the supporting evidence.

The report claimed more than 1,000 Russians benefitted from a state-sponsored doping programme.

It may have started out as a dispute between a track cyclist and her former coach.

But 10 months after Jess Varnish first made allegations of sexism, discrimination and bullying against Shane Sutton - and British Cycling - it is not just the reputation of the country's most successful and best-funded Olympic sport that is on the line.

After an unforgettable and relentless year for sports news, what does 2017 hold in store? Plenty, as sports editor Dan Roan explains:

There's no football World Cup, and it may not be an Olympic year, but expect 2017 to revive fond memories of the London Games, with a host of major sports events on the horizon.

Buoyed by Britain's remarkable success in Rio last year, track and field will take centre stage, first at the World ParaAthletics Championships, and then the IAAF World Championships, both held at London's former Olympic Stadium. It is the first time the two events have been held in the same city, and the same summer.

It was the year when sport simply never paused for breath.

For those of us covering this area of news, 2016 has been just as relentless, momentous, frantic and exhausting as it was for our colleagues in Westminster and Washington, trying to make sense of a defining year in politics.

The president of the International Olympic Committee (IOC) Thomas Bach says he has "no regrets" about letting Russia compete at the Rio Games this summer, despite a state-sponsored cheating programme.

In an exclusive interview with the BBC, Bach stands by his handling of the crisis, but admits there are "deficiencies" in the current anti-doping system.

For British cycling, there is a lot more than titles at stake at the Road World Championships in Doha this week.

On Wednesday, the event's organisers - international federation the UCI - will announce if Yorkshire has won the right to host the 2019 edition of the sport's flagship event.