However, it concedes that many savvy Brits are now finding free ways of keeping fit.
Katie Roswell, the marketing director of PruHealth, said the study shows people's buying habits are changing as food costs rise and inflation increases.
"The worry is that the progression from credit to health crunch may worsen as people reduce outgoings by buying less fruit and vegetables, and continue to believe that all exercise is expensive," she added.
PruHealth is part of the Prudential group and claims to offer a "piece of mind" through its private health insurance.
It offers consumers home, car, pet and health insurance.
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