The city’s effort to net more revenue on the backs of tennis players and fitness buffs has backfired, chasing thousands of park users away with sky-high fees, a report has found.

After the city doubled the cost of seasonal tennis permits to $200 and recreation-center memberships to as much as $150, participation rates fell by roughly half over two years, according to the Independent Budget Office report.

The number of adult tennis permits sold dropped from nearly 13,000 to just over 7,000 between 2010 and 2012, while rec-center memberships dropped from roughly 96,000 to 46,000 in one year.

Parks Department spokesman Phil Abramson countered with figures that showed recreation use up in 2013 but that included children and others who pay no fees or discounted fees.