One of my favourite moments as an amateur runner is standing at the start of a race.

This moment not only marks the culmination of weeks' of training, but the camaraderie you experience while waiting for the minutes to tick down is some of the best I've ever known.

It doesn't matter whether you plan to run a marathon in three hours or seven, everyone is wishing each other good luck knowing the hard work that has gone into reaching this point.

The fact that so many people use these events not just as personal challenges but also to raise valuable funds for charities, often close to their hearts, only adds to the emotion and sense of solidarity.

But in all the years I've been running, I've never felt this more keenly than during a race that took place this month.

On November 12, my husband and I had the privilege and thrill of taking part in the Las Vegas Marathon and Half Marathon.

We were already booked to be on holiday in the US city at that time, so when we found out our break coincided with these races, we - of course - had to enter!

It was a spectacular event involving 30,000 people running up and down 'The Strip' at night with its famous lights flashing - and we proudly ran the whole way wearing our Diss and District Athletics Club vests.

But the day held a special poignancy, coming barely a month after the terrible shooting at the Route 91 Harvest festival where 59 people senselessly lost their lives and hundreds were injured.

The organisers had quickly altered the race routes to ensure due respect was paid to the site where the tragedy had occurred, and many runners - us included – turned to family and friends for sponsorship to raise money for local aid organisations and a victims' support fund.

It was a real lump in the throat moment when the race announcer revealed that in just a handful of weeks all of us standing at that starting line had collectively managed to raise millions of dollars.

This wasn't just an example of the accord that exists between runners, but the wonderful unifying force of sport, and to have been part of this mutual act of support, defiance and hope is something we'll never forget.

Steph Callen is a member of Diss and District Athletics Club