The four men died during the race in September 2005

In delivering his verdict, the coroner said he hoped organisers would look at ways of improving emergency access to the final stage of the half-marathon.

The inquest had heard that in one case an emergency vehicle had taken 45 minutes to reach a casualty.

The four men, whose ages ranged from 28 to 52, were from County Durham, Leeds, York and Kent.

They collapsed within an hour of each other and all less than three miles from the finishing line.

Organisers, Nova International, have promised to look into some of the issues raised, including better access for emergency services at some points in the course and the procedures for informing relatives in the event of a death.

'Physically fit'

The four who died were deputy head teacher Phil Lewis, 52, from Chester-le-Street, County Durham; 43-year-old civil engineer David Mahaffey, from York; company director Reuben Wilson, 28, from Leeds; and businessman Kieran Patching, 34, from Walderslade, near Chatham in Kent.

Terrence Carney, the Gateshead and South Tyneside Coroner, said they had all been physically fit and well-prepared for the event.

He said: "I am satisfied essentially that in each case the mechanism of death has been a sudden interruption in the rhythm of the heart, a so-called arrhythmia, the nature of which is not readily identified on post mortem but which suddenly induced this sudden cardiac event in each case.

"I am further satisfied that this phenomenon was a direct result of the stress on the heart caused by the prolonged exercise of their participation in this event."

Nova International chairman Brendan Foster said: "The 25th Great North Run in 2005 will always be remembered with great sorrow as the race when four runners died.

"Our thoughts, prayers and sympathies remain with the families."