The organisers Run 4 Wales have promised a full review will take place but they were “100% satisfied” with the medical plan in place at last weekend’s Cardiff Half Marathon (7 October 2018).  Ben McDonald, 25, from Glamorgan and Dean Fletcher, 32, from Exeter, went into cardiac arrest after crossing the finishing line. Both later died at the city’s University Hospital of Wales.

The runners head off along Chichester Street in the Belfast City Marathon – Do they know the risks?

It has been a bad year for deaths at running events. No less than four runners died at the Great North Run last month. The eldest of these, deputy headmaster Phil Lewis, 52, was running his 24th GNR, having only missed the first edition.

Earlier this year Stephen Heaney, 50, from Limavady died during the Belfast Marathon and Masterchef Matt Campbell was a fatality when close to the finish of the London Marathon in April.

It should be remembered that the man who inspired the modern event, Pheidippides, collapsed and died after running from Marathon to Athens to deliver news of the victory of the Greeks over the Persians. “Joy to you, we’ve won” he said before gasping his last breath.

A hemerodrome (professional running courier) by profession, Pheidippides was sent to Sparta to request help when the Persians landed at Marathon. He covered about 240 km (150 mi) in two days before running 40 km (25 miles) from the battlefield near Marathon to Athens to announce the Greek victory.

This is a common theme in that most of the deaths occur after the participant has finished or almost completed the race. Experts point out that even after crossing the finish line a lot of circulating adrenaline is still coursing through the body while blood starts to pool in the legs. Because the muscles are no longer contracting to push the blood back, this places an enormous strain on the heart.

The greater majority of deaths among younger runners is on account of cardiac arrest while in older runners it is due to heart disease or arteriosclerosis, a deterioration of the valves around the heart. Unfortunately, many heart problems especially in the right ventricle cannot be detected when the runner is at rest.

Anyone taking on a marathon should realise the physical demands of running 42.2 kilometres (26.2 miles).  At rest, the heart pumps approximately five litres of blood around the body every minute but this increases to 35 litres when running. The body can cope quite easily with this extra strain for short periods of time but when you get into two, three, four hours or more, the strain on the heart increases exponentially.

All too often when someone completes a six week couch to 5K programme, the first question is “when can I run a marathon?” To prepare adequately for a marathon should take at least a year of consistent training and racing shorter distances. Most people do not conform to this advice before making their debut at the marathon.

A Canadian study shows that running a marathon, even for professionals, causes damage to the heart although this self-heals with time. For this reason downtime of several weeks, if not months, is needed to allow the body to complete the repair process and let the immune system get back to normal. Turning out in a race the week following a marathon does not make you a hero –  probably a fool risking their health and possibly more!