A city gym is hoping to get the community's muscles flexing as it holds a fun weekend in aid of two good causes.

Fitness First, at Riverside in Norwich, will be raising money for the Ella-Grace Fund and Macmillan Cancer Support as it throws open its doors for group exercise classes as well as running a bank holiday event at the piazza outside the Odeon cinema.

Junior Johnson, the health and fitness manager at the centre, said by holding the fun day and raising cash for charities, the gym is hoping to play a key role in the community.

He said: 'We have been given the title of community gym, and we don't want it to just be a title. We have a responsibility and service to provide for the community, while promoting health and fitness.'

The weekend events will be split between the gym itself, and the central piazza area.

X-leisure, the company which looks after Riverside, has helped organise the free family entertainment on Sunday and bank holiday Monday, which will include a giant dartboard, giant basketball game, face painters, craft workshops and balloon modellers.

As well as this, the strongman competition, based on the World's Strongest Man, will include 12 events, with heats taking place on Sunday, and the finals on Monday, with an entry fee of �10.

Mr Johnson added: 'There are still places available for the competition, so if anyone wants to take part then get it touch. All the money will go directly to our charities.'

Within the gym, fundraising activities include Mr Johnson's seven-hour sponsored spinathon class on Saturday – which is cycling on a stationary bike.

There will be a �2 charge for the spinathon class and other classes on Saturday between 9am and 5pm, from body pump, body attack and body combat, as well as Zumba and yoga.

Half of the money will go to the Ella-Grace Honeyman Fund, which was formed by friends of the family anxious to offer help and support after Ella-Grace, a one-year-old from Hevingham, was diagnosed with the life-threatening brain condition Vein of Galen Malformation (VGAM) in June 2008.

The other half will go to Macmillan Cancer Support which helps those living with cancer.

For more information and to book call 01603 723470.