Sports lecturer’s lesson in how to shed nine stone

However, she previously weighed in at a hefty 20 stones – and was hardly a model of healthy living.

But now the 36-year-old lecturer at Sheffield Hallam University has shed a staggering nine stones in just 14 months, and was yesterday rewarded for her success with the Online Slimmer of the Year prize at Rosemary Conley’s 2012 Diet and Fitness Magazine awards.

Mrs Purvis-Gisborne was one of eight super slimmers from across the country to receive their prizes – along with £1,000 cash – from Rosemary Conley at a ceremony held at the London Marriott County Hall Hotel yesterday.

It took a health scare for Mrs Purvis-Gisborne, from Dronfield in Derbyshire, to change her lifestyle.

“I went to my doctor’s surgery for a regular check-up and had my blood pressure taken”, she said.

“It was high and I realised that medication was the next step. That was what scared me into taking action.

“I knew about Rosemary Conley’s plan and knew it was about healthy eating and exercise.

“As there wasn’t a class close enough to me that I could get to and that would fit in with work, I decided to do it online.”

Previously, Mrs Purvis-Gisborne – who now weighs 10 stones 12 pounds and wears size 12 clothes – had a weak spot for ice cream, pizza and biscuits.

But, in sticking to Rosemary Conley’s low-fat eating plan, she lost seven-and-a-half pounds in the first week of her diet, and five pounds in the second.

“I ate a lot of biscuits, they were my real weakness”, she said.

“There was a biscuit tin in the office and I’d find it pretty easy to have three biscuits with a cup of tea.

“By the end of the day I’d have eaten almost a full packet.”

Within the first month of joining Rosemary Conley’s internet slimming club, Mrs Purvis-Gisborne succeeded in shedding an impressive 1st 4lb.

She and her husband cooked healthy, low-fat vegetarian meals together and, the more weight she lost, the more she started to increase her exercise regime.

After starting to run for just 10 minutes at a time, she built up her running to half-hour intervals and then signed up for the London Marathon.

She now trains five times a week and is hoping to complete the 26-mile race this spring in a very respectable four-and-a-half hours.

Before that, however, she has the small matter of a 10-mile race in February and a half marathon in March to train for.

Mrs Purvis-Gisborne said: “My blood pressure is now at a healthy level, but the biggest reward is knowing I now practice what I preach to my students, who now tell me how fantastic I look.

“Weighing 20st and lecturing others on how the human body responds to exercise made me feel embarrassed.

“I’m so much fitter now, and it’s given me so much confidence.

“I remember the first time I tried a size 12 on in a changing room.

“I spent a few minutes just looking, from every angle, as I couldn’t believe it fit.”

As for her advice to others out there wanting to lose weight?

“Just do it”, she said. “If I look back to what I was like before, I wasn’t being honest with myself. I was eating what I wanted, when I wanted, not caring about the consequences.

“Before, if I went into a shop and they didn’t go up to my size, I’d tell myself that they weren’t making clothes for ‘real’ women.

“I was making excuses, but I knew deep down that, if I was that size, I was overweight.

“I was in a lot of denial. But now I realise that if you want to lose weight you have to make some changes – big changes – for life.”

She added: “Losing weight is absolutely worth it. I can’t describe in words just how wonderful it feels to be a size 12 and have all this energy.”