When life changes you, you find new reasons to make a difference.

I’ve always believed in helping others. In 2001, I began running marathons for charity, but my relationship with fundraising became deeply personal in 2010, when our son Jack became seriously ill.

On Sunday, 5 December 2010, our 10-year-old son suddenly became critically unwell at home. He was rushed to Chelsea & Westminster Hospital, where he received life-saving treatment before being transferred to Great Ormond Street Hospital for specialist care.

Jack was diagnosed with a rare pancreatic tumour and faced an incredibly difficult journey.

The doctors, surgeons, nurses and wider team at Great Ormond Street Hospital gave Jack the specialist care he needed and, most importantly, helped save his life.

That experience changed me profoundly.

In the years that followed, I became a Great Ormond Street Hospital Charity Ambassador and began taking on challenge after challenge to raise money and awareness — from 5Ks, 10Ks and half-marathons to full marathons, ultra-marathons, Race for the Kids and other fundraising events.

For me, running became about much more than running.

It became a way of giving back.

Every mile, every event and every pound raised has been my way of saying thank you to the people who helped our family when we needed them most.

I will always be grateful to Great Ormond Street Hospital and the extraordinary people who cared for Jack.

And I will continue to support the hospital whenever I can.

Because sometimes the greatest strength we can build is the strength we use to help someone else.