David Weir has opened the London Marathon Running Show prior to competing in the race for the 20th time.
The wheelchair racer has triumphed on a record eight occasions at the annual race.
Weir launched the exhibition at ExCeL Centre, which is expected to be visited by runners and visitors over the coming days.
London Marathon organisers state more than 40,000 runners registered to take part when attending the exhibition last year.
Around 76,000 visitors were recorded in 2018 in the four days building up to the event.
The exhibition is viewed as an opportunity for major athletics brands to showcase their latest products to runners.
Organisers state one of the biggest stands is devoted to their London Marathon Superstore with this year’s range of New Balance souvenir and technical clothing.
Every runner participating must visit the exhibition to receive their race pack.
It is claimed this will enable them to visit the stands and listen to guest speakers.
Visitors can also take part in activations, such as the Tumbleator – a moving platform – which enables them to test their speed against the pace set by the world’s best marathon runners.
Weir is set to compete in the men’s T54 race on Sunday.
The Paralympic events will form part of the World Para Athletics Marathon Championships.
It will mark the second time London has hosted the Championships after the first edition in 2015.
At this year's race on April 28, three different medal events will be held, matching the events set to take place at next year's Paralympic Games in Tokyo.
They will be the men’s and women’s T12, including T11 classed athletes, the men’s T46, including T45, and the men’s and women’s T54 also featuring the T52 and T53 categories.
With the Paralympics edging nearer, the top-four ranked athletes in each medal event will gain one slot for their nation in Tokyo.
Each country will be able to enter six athletes into each event in London, while the athletes in question must have either gained the qualification standard or been invited by organisers.