Hundreds of hardy souls pushed themselves to the limit while raising funds for Cancer Research UK over the weekend.
An estimated 310 people took part in a 10k race through Roundhay Park that was staged by the charity on Saturday.
Participants ignored the wet weather to tackle terrain including muddy trails and freezing cold streams, with one of the main challenges they faced being the struggle to stay on their feet.
It is hoped the Tough 10 event will end up raising tens of thousands of pounds for Cancer Research UK.
Charity spokeswoman Nicki Embleton said: “It was an amazing atmosphere. We had some people running on their own while others came together in teams.
“It was also nice to see plenty of couples taking part and crossing the finish line hand in hand – there were lots of smiling faces.”