New year resolutions to hit the gym will be harder to keep because membership costs at local authority-owned leisure centres are rocketing, Labour has claimed.
Individual fitness sessions are also becoming more costly and the rising prices risk putting people off attending, the party warned.
Annual membership bills have increased by up to £100 at two-thirds of public gyms since the Coalition took power, according to research carried out by the Opposition.
The survey of 95 English councils found a yearly pass now costs £368 on average, an increase of £15 since 2010 - but 48 councils introduced above- average hikes.
Single classes after work on weekday evenings have risen in price at almost every local authority centre and now average £5.95 per visit, Labour found.
Shadow public health minister Luciana Berger said: "Millions of people across the country will want to kick-start 2014 by getting fitter and more active.
"There is a real risk, however, that many people will be put off from keeping to their new year's resolutions by soaring gym charges and David Cameron's failure to tackle the cost-of-living crisis.
"With worrying obesity levels and stagnating physical activity levels, we desperately need ministers to make gym and leisure facilities accessible and affordable for all."
The highest increase in annual membership costs - £98 - was introduced by Southampton City Council, followed by a £91.50 hike by Wealden District Council and £80.50 by Hastings Borough Council.