More than £1,200 was raised during a 12-hour day of workouts at a Northampton gym.
Daniel Hill, Sam Davies, Alex Coe and Alex Barrick, who are all members of Project Fitness in Northampton, will be taking part in Battle Cancer later this year.
Battle Cancer, which is held in London on October 20, is the UK's leading fitness charity competition which will see hundreds of athletes taking part all raising money for charity.
The team officially kicked off the fundraising last Saturday (July 14) with a 12-hour event at the gym in Moulton Park which consisted of a crossfit style workout every hour from 7am to 7pm.
The exhausting workouts included running, pull ups, press ups, squats, lifting and burpees.
Daniel said: "So far we have raised over £1200 from the Saturday event for our chosen cancer charity, Macmillan Cancer Support.
"We are very pleased. We had people dropping in throughout the whole day joining in and hanging out. We raised an additional £120 on the day selling cakes and refreshments."
The group will continue to fundraise in the lead up to Battle Cancer.
To make a donation to support the team, click on the Just Giving page here