Youngsters can work out for free at a Hounslow gym as part of a drive to tackle childhood obesity.
Children aged between three and five can attend up to four free keep fit classes a week with their parents at Xercise4Less gyms, including the branch at the former bingo hall in Staines Road, Hounslow.
The fitness chain launched its new initiative Xercise4Kids on March 8, in response to recent figures showing a third of children are overweight or obese when they leave primary school.
The 45-minute classes were developed by Xercise4Kids coordinator Sarah Philp to get parents exercising together with their children.
They are designed to provide a challenging but fun workout, with different themes including an underwater kingdom and jungle exploration.
At the end of each eight-week programme, children are presented with a certificate to document their progress.
'We will tackle childhood obesity head on by educating families'
Ms Philp said: "Xercise4Kids was inspired by the lack of inter-generational activity available in the UK for both parent and child.
"It eliminates the childcare barrier and also encourages interaction between parent and child as opposed to the current child movement classes offered."
In Hounslow, 37% of 10 and 11-year-olds are overweight or obese, according to figures highlighted recently by the British Heart Foundation , which has called for a ban on junk food TV adverts.
Kiefer Stewart, general manager of Exercise4Less in Hounslow, said: "In the UK we currently have children that have a shorter life expectancy than their parents, mainly because of a basic lack of activity.
"By providing free exercise classes to every child aged three to five we will tackle childhood obesity head on by educating families to the benefits of a healthier, happier lifestyle."
Parents wishing to attend the classes with their children can register online at the Xercise4Less website or call the Hounslow branch on 020 3817 4080.
