Sebastian Coe admits that athletics' world governing body was "crumbling" when he took over four years ago, but insists progress has been made on Russian doping and levelling the female playing field by forcing athletes such as Caster Semenya to regulate their testosterone levels.
"We've covered a lot of ground, there's no question about that," IAAF President Coe told AFP in an interview in Zurich, host of the opening Diamond League final.
"Some of it because I wanted to make changes... and some of it, I openly admit, was forced upon us.
"We've made a mountain of changes such as a proper constitution to meet modern demands. The centrepiece of that was the Athletics Integrity Unit (AIU), really the first of its kind in international sport, and that's working very well."
Coe, who won 1500m Olympic golds for Britain in 1980 and 1984, beat legendary former Ukrainian pole vaulter Sergey Bubka to take over as head of the International Association of Athletics Federations from the now-disgraced Senegalese Lamine Diack in 2015.
It was far from plain sailing for Coe after Diack's 16-year reign ended in chaos amid accusations he and his son obstructed sanctions against Russia for doping in return for payments.
The IAAF suspended Russia in November 2015 after the allegations of state involvement in doping emerged and Russian track and field athletes were banned from competing under their own flag at the 2016 Rio Olympics.
The country was re-admitted to the Olympic fold last year, but the IAAF continues to ban Russian athletes from competing in their national colours.
"I see the first four years as being a process of change, time for change, and we needed to do that," said Coe.
"On Russia, we made a judgement early on that this was an issue that could not be ignored. It was not simply because of its high-profile nature, but it also summed up some of the other challenges we had around the way we needed to revisit our whole anti-doping approach.
"The creation of the taskforce (on Russian doping) has served us well, it's removed subjectivity," he said, adding that the process had at times been "heart-pounding".
Russia, Coe said, is "moving in the right direction, but the criteria still need to be met".
There were still concerns about coaches in the system, while the AIU is in the process of analysing materials handed over from Russian anti-doping laboratories.
"Yes, we've been tough, but we've been tough because we felt that it was in the interests, ultimately, of Russian sports as well as our interests in our own ability to have a level playing field within international sport."
Coe is guaranteed a second four-year mandate as IAAF president as he is the only candidate in September's elections.
"The next four years, I hope, will clearly be focused on the fun elements, (and we will) turn our attention to what will help our sport grow," he said.
"We couldn't do that until we had really secured the house and the house was crumbling."
Coe admitted to regretting not being able to tackle the issue of creating a more attractive global calendar, with a focus on innovation around one-day meetings, sooner in his mandate.
"We were doing everything we possibly could do to concentrate on all elements, but it's very difficult to do when you're in the trenches -- and we were."
Turning to South Africa's double Olympic 800m champion Semenya, who is unable to defend her world title in Doha next month because of the IAAF ruling that insists she and other female athletes lower their testosterone levels, Coe was steadfast.
"I'm neither happy nor unhappy," the Briton said of the ruling that tries to curb masculine attributes in females stemming from differences of sexual development (DSD) that the IAAF argues create an unfair advantage over other women in events between the 400m and mile.
"I tend not to over-personalise these things. I had a responsibility as president of the sport... sometimes you need to grasp difficult issues, not kick the can down the road for some other Council or president to deal with.
"It's not a personal, individual issue. It's not about one athlete, one country or one continent. These are regulations that have been tabled and the Court of Arbitration for Sport (CAS) found them necessary and proportionate."