There are two ways of looking at it. One viewpoint, held by those we can call the optimists, argues that catching dopers shows athletics is slowly winning the battle to weed out cheating.
The other group, let us call these people the realists, suggests that the steady flow of high-profile drugs busts only proves the endless hold that illegal substances have over the sport.
As part of the Abbott World Marathon Majors – a collective of the world’s six leading marathon races – the London Marathon can legitimately claim to do more to combat doping than almost any other event.
Thanks to their efforts, more than 150 elite marathon runners are now obliged to submit to extra out-of-competition testing a minimum of six times a year and it was at one of these tests that Jemima Sumgong, the reigning London and Olympic marathon champion, flagged as positive for the banned substance EPO earlier this month.
The plan had been for Sumgong to defend her title in London today, but her absence – in addition to causing some hasty amendments to promotional material for the race – has instead cast yet another cloud over a major event.
“We are at the forefront of ensuring integrity in our sport,” insisted Hugh Brasher, London Marathon race director, this week.
“If there is a positive out of the disappointment it is that the testing was paid for by an organisation that we are part of.
“We are determined to stamp out any cheating. We will test people again and again.”
It is amid a backdrop of more than 40 Kenyans caught committing doping violations over the past six years that several leading runners from the east-African powerhouse are ready to step into Sumgong’s shoes this Sunday.
Meanwhile, athletics fans are left trying to convince themselves to believe what they see.
There has been no shortage of scathing criticism from Sumgong’s compatriots in the pre-race build-up this week, with Florence Kiplagat close to tears as she admitted she was “really ashamed” of her team-mate’s cheating and Vivian Cheruiyot calling the drugs bust “embarrassing”.
Fellow Kenyan Mary Keitany was similarly harsh in her assessment and in Sumgong’s absence now looks the most likely candidate to win what would be her third title on the streets of London.
Behind those at the head of the field, the evergreen Jo Pavey leads a ‘race within a race’ with half a dozen British women maintaining hopes of finishing among the top two home nation runners in order to guarantee a place for the London World Championships this summer.
Pavey, 43, is the fastest of the British contingent, but faces stiff competition from Alyson Dixon, Charlotte Purdue and Susan Partridge.
The men’s race is also shorn of last year’s winner, with Eliud Kipchoge, the world’s undisputed best marathon runner, opting against defending his crown and instead bidding to become the first man in history to break the two-hour barrier in a Nike-sponsored publicity stunt next month.
Already considered by many as the greatest distance runner of all time, three-time Olympic and five-time world track champion Kenenisa Bekele narrowly missed out on adding the marathon world record to his 5,000m and 10,000m records with a phenomenal 2hr 3.03min victory in Berlin last year and is odds-on to triumph on Sunday. His Ethiopian team-mates Tesfaye Abera and Feyisa Lilesa look most likely to challenge for victory.
Already pre-selected for Britain’s World Championship team, Callum Hawkins has skipped the race in London, leaving a top trio of home challengers to battle it out for the two remaining spots.
Scott Overall and his training partner Chris Thompson have plenty of experience over the distance, but Tsegai Tewelde beat them both last year with the most eye-catching, unexpected performance. The Eritrean asylum seeker led for much of the race and eventually finished second of the British contingent to qualify for the Rio Olympics.
A regular feature in his home city, David Weir will bid for a seventh London Marathon win on his 18th consecutive appearance in the men’s wheelchair race.