A Swansea man is taking on an extreme challenge to run his second marathon, 36 years after his first.
In 1982, Chris Larkin ran his first marathon but issues with his weight have stopped him being able to run another since.
Chris says that a number of factors, including poor diet and sustaining a severe leg injury, led him to reaching a weight of over 36 stone in 2016.
At this point Chris said he realised his weight was putting his life in danger.
Chris, who now weighs 27 stone, is trying to combine fundraising with extreme-weight loss by attempting to swim 130k by the end of August to raise money for Alzheimer's UK.
He has taken up the Running Down Dementia campaign, which encourages people to run 100km during the summer, in honour of his parents who both died with vascular dementia.
A knee injury means Chris, a grandfather of three, cannot run, so he has been clocking up the kilometres in the Village Hotel pool.
The lighting engineer began the challenge at the end of May and originally targeted 100km, but he has now upped his target by 30km.
He says his aim is to reach the weight of 15 stone, a loss of more than 21 stone.
Chris says that it was his parents' battle with dementia that has inspired him to take up the challenge.
For the final 2km he hopes to swim in the sea from Boscombe Pier to Bournemouth Pier on Friday, August 31.
Chris had initial success in his weight-loss mission by changing his diet to avoid processed food, but says he took it to the next level when he joined a gym and got help from a personal trainer.
Chris is among nearly 5,000 people taking part in Running Down Dementia this summer. They have so far run more than 385,000km and raised over £290,000.