Border Collie Meg gave an exhausted Simon Coxell a great big lick after he finished his final 500 bupees.
Simon set himself the challenge to do 500 burpees a day throughout May in aid of the Firefighters Charity and Skegness Natureland.
Already more than £1,400 has been raised on Simon's JustGiving page.
Simon, who has served as a firefighter in Skegness for 32 years, is no stranger to massive charity challenges. Two years ago he did a similar challenge with 2oo burpees a day for the Firefighters Charity and the Bone Cancer Research Trust.
"I'm retiring later this year and just wanted to get a good one in before then," he explained.
His final day, wearing his back pack weighing around 20kg and his breathing apparatus, was on May 31.
"Within minutes of finishing I was out on a call - but that's the way it goes," he said. "I'm feeling it now but am booked in for some physio - Olivia Brown has been brilliant keeping my body going throughout the challenge."
Simon chose Skegness Natureland as a local charity but also the Firefighters Charity for helping him when he needed it.
"I ruptured two disks in my spine and the Firefighters Charity supported me through rehab. I wanted to give something back," he said.
As well as support from Meg, who tried to take his mind off it by bringing him a ball, Simon also got some encouragement from work colleagues.
"Some of them joined in for around 200 burpees," Simon added. "We all do fitness at work but 500 burpees is a bit extreme."
There are no plans to take things easier in the future. Simon is a member of Phoenix Fitness and plans to become a Personal Trainer there when he retires.
"I'll probably rest a bit for a while," he said. "But give me a few weeks and I may well fit another challenge in before I retire."
There is still time to support Simon on his JustGiving page here.