Mum-of-two Sam Boyd decided to lose weight and get fit after her father-in-law died from cancer.
After years of making half-hearted trips to the gym to try to lose some weight, Sam was shocked into action.
Losing her father-in-law not long after a close friend also died from cancer made her aware of her own mortality. She decided to do something to improve her fitness.
For Sam, losing weight meant that she felt and looked healthier, happier, and more self-confident. She could also take part in more family activities.
At 5ft (152cm) tall and weighing 10.2 stone (65kg), Sam was overweight and at greater risk of developing chronic diseases, such as type 2 diabetes.
She began a healthy weight-loss diet and regular exercise. The diet was designed to help Sam lose weight gradually by eating smaller portions at meal times and choosing foods that kept her feeling fuller for longer.
"I had become used to eating large portions," says Sam, a business development manager from Hemel Hempstead. "The diet plan got me used to eating smaller portions."
After five months, Sam was transformed. She had lost 2.5 stone (15kg) and 10 inches (25cm) from her waist.
Sam took up running to avoid putting on weight again. "My husband and daughter are keen runners, so that gave me some motivation to take up running and train for a half marathon," she says.
She started out slowly, alternating running and walking over a 5km route. "At first, I'd do a minute of running and then walk for a minute," she says. "Gradually, I was walking less and running more, until I could run the whole distance."
Within four months of starting, Sam was running three to four times a week. She entered several short distance runs – 5k and 10k – before attempting a half marathon, which is 21km (13 miles).
"I feel so much better now and I've got loads more energy," she says. Before she lost weight, she would have struggled to make it to the end of the road without running out of breath.
Sam says losing weight has really boosted her self-esteem. "I've dropped from a size 12/14 to a 6/8," she says. "It's a great feeling to be able to go into a clothes shop and pick up a size 8, knowing it will fit."
'Here to stay'
The new Sam is here to stay. She took the decision to get healthy and, with a bit of self-discipline, she's succeeded. "It's about re-educating yourself," she says. "The diet taught me about portion control and healthy eating. It has given me good habits, which are now part of my lifestyle."
To stay motivated to exercise, Sam regularly takes part in running events with her husband and daughter, from 5k charity runs like Cancer Research UK's Race for Life to half marathons.
"I used to get out of breath walking up the stairs," she says. "I never imagined myself doing a half marathon."
Sam remembers the effort she put into getting back into shape. This memory is enough to prevent her falling back into old habits. "I kept a diary during my weight loss programme and I've got lots of photos of me before I lost the weight," she says.
"They remind me of how I felt before and my initial motivation to turn things around. I think about how I looked and how unhealthy I felt, and I don't want to go back to that."