It has a reputation for being flat, fast and very popular and so it proved again as personal bests tumbled.

In total there were slightly more than 13,000 finishers with 52 from North Herts Road Runners among the field.

And two of the 20 PBs recorded have also entered the club's record books.

Astrid McKeown’s time of one hour 31 minutes 24 seconds took almost seven minutes off the previous best for a veteran female over 50 while Andrew Leach’s 1:13:51 beat the MV60 record by more than 18 minutes.

The first female squirrel over the line was Katie Harbon, eighth in 1:17:31, while first male for the club was Mike Roberts.

He came 50th in another PB, this one timed at 1:10:49.

The biggest improvement came from Nicola Withington who lopped a massive 27 minutes off her previous best time, finishing in 1:56:58.

One Squirrel also sacrificed her own race to help perform CPR on a runner who had collapsed close to the finish.

A club spokeswoman said: "Helen Nuttall was a true hero on the day as she provided essential CPR along with two other doctors to a fellow runner who had collapsed at the 12.6 mile mark.

"Thankfully they revived the young man and he was taken off in an ambulance and reports received state he made a good recovery."

Fairlands Valley Spartans were also inundated with new fastest times.

Linda George was very pleased to beat the two hour barrier when she finished 1:59:34

Craig Bacon shaved 12 seconds off his previous, coming home in 1:39:11, while Vicky Archer took four minutes off her PB with 1:51:58 and Stuart Archer improved to 1:23:18.

Nick Gill and Mike Jeffs were in hot pursuit of the latter Archer and while they never caught him, both managed PBs.

Gill went four minutes quicker than last year to finish alongside Jeffs in 1:23:21.

Andrew Patterson stormed round to finish in 1:11:03, nearly 90 seconds faster than before.

He said: "Conditions were ideal for me out there, no wind or rain and a flat, fast course.

"It was my first time doing Cambridge and I loved it.

"Well done to all the Spartans, some great times clocked."

A team of eight Stevenage Phoenix were also in attendance and they too were quick.

Jay Papa was in first, not only setting a PB but also a club record of 1:28:14.

Paul Smith is coming back to his pre-injury form, running a strong 1:40:35 and setting a new age category record.

PBs also belonged to Conor O’Neill (1:49:59) and Charlie Day (2:48:08) and there was a great first time run from Mel Tanti (2:13:43).

There were two other half marathons which attracted some.

The Berkhamsted Half is the opposite of Cambridge, with barely a flat part and just over 900 runners.

Wendy Tharani of FVS finished in 2:12:47.

Middlesbrough was the other destination, Ashley Bates of Phoenix setting a PB of 1:52:04.

North Herts Road Runners had a couple running at the Golden Fleece Circuit at South Cave, East Yorkshire.

Anna Gibson and Jill Tooley-Boys completed the 27-mile event with canine pals Flora and Lulu.

They completed the challenge in six hours 24 minutes.