The report cited studies that show girls enjoy sports and physical education less than boys.
Dr Louise Hardy, senior research fellow at the University of Sydney's centre for physical activity, told the Daily Telegraph activities like Zumba or pilates could lift young girls' interest in fitness.
But Grant Schofield, the director of AUT's Centre for Physical Activity and Nutrition, said such recommendations completely missed the point. Overseas research showed children now spent about four times more time with their parents as in the mid-1970s.
"Almost all of that time sitting in cars. Getting taken to and from organised activities, where in the past kids have just run around neighbourhoods - free-range kids.
"And that's really what's going to keep obesity away for boys and girls - movement that's part of everyday life all the time."
Dr Katie Fitzpatrick, research fellow at Auckland University and former head of health at Tangaroa College, said her research into Year 12 and 13 girls in South Auckland showed they were active in a wide range of exercise.
"And it's a totally normalised cultural activity for boys to dance - but there's still a presumption in some parts of society that it's not tough. I think we can get stuck with splitting it up around gender. When if you did a social class-split, or an ethnicity-split, or a tall person/short person-split, then you'd get a different picture."
Gordon Paterson, chief executive of Physical Education New Zealand, said it was important for phys ed classes to include a wide range of actions and motions so children could choose what appealed to them "and run with it".