The website also claims to have recorded its highest-ever number of unique users with 811,000 – 21% higher than in 2011. During the month, page views reached more than 6 million, up 7% on last year.
The increase in traffic was driven by a concerted social media and online campaign to support the Virgin London Marathon 2012.
Additionally, runnersworld.co.uk capitalised on the heightened profile of running in the weeks leading up to the marathon by encouraging beginners to take up the sport.
Runnersworld.co.uk showcased expert marathon advice on its homepage, Twitter and Facebook accounts. All marathon enquires were responded to while directing readers to useful articles on the website.
A partnership with Saucony at the London Marathon expo invited runners to look for a secret code, published only on Twitter (@runnersworlduk), for a chance to win a pair of running shoes.
It also tweeted throughout the marathon, encouraging readers to cheer on community members.
Alun Williams, UK group publishing director, said: "Runnersworld.co.uk is one of the most profitable and innovative magazine websites in the UK, and the record-breaking performance in April is a testament to the ingenuity and drive of the editorial team, coupled with some great advertising partnerships. I'm confident that this month is a stepping stone to even better figures in the future."
In 2011, the magazine launched its first-ever eBook for sale on Amazon’s Kindle and Apple devices, Runner's World Coach, as part of an ongoing expansion of the Runner’s World brand across multiple platforms.