Many of them entered the event to raise money for good causes and have very personal attachments to the charities that they have picked.
Here are some of the inspirational stories our reporters heard when down at the Great South Run this year.
Sharon Wood, 50, was running for the Huntington’s Disease Association and in memory of three family members who have died from the condition.
Sharon said: ‘My mother, Sylvia Ryan, 36, died from Huntington’s when I just five and my brother was one. We were separated and went into care. It is a degenerative disease which affects your cognitive and physical ability.’
The disease is hereditary and also killed her uncle and grandmother.
Sharon, who raised £1,000, said: ‘There is a 50 per cent chance I could have inherited the gene. There is a test you can do but I decided not to get it done as I just want to live my life.’
Many runners have been personally affected by the diseases they were raising money to combat – non more so than motor neurone disease.
Vanessa Maple, 43, lost her father to the illness six years ago.
‘It is such a debilitating illness. My dad went from being fit and healthy to needing to be fed and washed in just three years,’ she said.
Running with Vanessa to raise money the Motor Neurone Disease Association (MNDA), was Gary Skerrat, 55, who lost his friend, Keith Miller, to the deadly illness.
Gary, who has taken part in many fundraising events, said: ‘There will be no finishing line until we find a cure. This is such a terrible disease. Your mind remains perfectly healthy while the rest of your body breaks down. Keith was a proud man and by the end he wouldn’t let us come and see him.’
Tom Brown, 26, has also seen his family afflicted by the disease.
Tom said: ‘My grandfather, Joe Frazer, died from motor neurone disease 10 years ago followed by my uncle, Murray Frazer, seven years later. As a family we can’t believe it has happened to us twice. It’s an awful disease which gets progressively worse.’
Tom, who was joined by 50 other MNDA runners, has raised £361 for the charity.
Tom said: ‘The MNDA were so helpful to our family that I wanted to give something back. They provided emotional support as well as practical care such as nursing help at home and wheelchairs.’
However for Vanessa, Gary and Tom, taking part in the run was just as much about raising awareness of the disease as well as raising money.
Another charity which was well represented at the run was Alzheimer's Research UK.
Charles Peach, 55, lost is mother to the disease in 2016.
Charles said: ‘It’s the worst illness possible. Seeing the person who loved you and looked after you deteriorate to the point where they don’t even know who you are is just shocking.’
Gladis died from the disease the day before her 90th birthday.
Charles added: ‘I’m running today for my mother who is always close to my heart. The charity do such a fantastic job in providing families with support as well as specialist nurses and care.’
Lee Robins, 60, has seen three family members and a friend affected by Alzheimer's.
Lee, who raised £400, said: ‘My Aunt Dorothy is still alive but needs specialist care. The society provides a residential nurse which supports her in her home.’
Co-owner of NA Curtain Walling in Horndean, Robbie Welch, 53, was running to raise money for The Roberts Centre Portsmouth after former colleague Louise Bradley died of cancer last year.
Dressed as a parrot for the run, Robbie said: ‘Louise died last year so we always do things to raise money for cancer support. We’ve had a team of 12 who took part and children took part in the junior race.’
Speaking of wearing the parrot outfit, he added: ‘Sweat was pouring off me – it was tough. But it’s good to support good causes and run in the memory of Louise.’
Paul Fuller, 52, of Warwickshire, raised £400 for the Juvenile Diabetic Research Foundation after his 12-year-old niece became ill with type one diabetes.
He said: ‘It’s a brilliant race, I loved taking part. I ran to raise money for the charity, with the condition a growing problem it is important to do all you can to help.’