Dunedin adolescents are carrying an average of 5.6kg to and from school each day in their school bags.
And for many teenagers and their parents, the weight of the schoolbag is perceived as a barrier to walking or cycling to school.
These are the latest research findings of the University of Otago's Beats Study (Built Environment and Active Transport to School) team, led by Associate Professor Sandy Mandic.
The data was collected from 2014 to 2017 from pupils at Dunedin's 12 high school, and showed excessive bag weight could be more a matter of perception than reality, Prof Mandic said.
"However, schoolbags are heavy, there is no question about that.''
Two-thirds of parents and more than half of pupils felt their schoolbags were too heavy to walk or cycle to school.
Prof Mandic said much research in the area of bag weights had focused on shoulder and back pain in adolescents, which was prevalent.
"However, this study of our data looked at bag weights as a perceived barrier to active transport to school,'' she said.
"Those who used motorised transport were much more likely to perceive that they carried heavier bags.
"But in fact their bags weighed the same as adolescents who used active transport - and that is fascinating.''
Dunedin teenagers Catherine Davidson (18), a year 13 pupil at St Hilda's Collegiate, and her brother, Marcus Davidson (14), a year 10 pupil at Logan Park High School, both carry sizeable backpacks to and from school each day.
Their transport to and from school is a mixture of being driven and walking - depending on activities after school.
The contents of their backpack-style schoolbags are typical of high school pupils, and include laptops, folders, textbooks, reading books,pencil cases, diaries, calculators, lunch boxes, drink bottles and umbrellas.
They also regularly carry musical instruments, and Marcus has sports gear.
"It can get pretty heavy, especially as I have moved through the years and have more study to take home,'' Catherine said.
Both felt their bags were "pretty much average'' for their peers, and neither felt they were too heavy to carry when walking.
The teenagers' mother, Dunedin School of Medicine senior research fellow Dr Kirsten Coppell - who has a background in public health and nutrition - has taken a close interest in the Beats Study since it began in 2014.
The issue of bag weights was one of many factors which could influence choice around transport to school among young people and their parents, she said.
"It is a subject that has definitely arisen as deserving more investigation,'' Dr Coppell said.
Because the Beats Study was not originally set out to look specifically at the question of bag weights, the research team had now designed new questions to be included in the rural phase of the research.
Prof Mandic said activity among adolescents was a public health issue, and there were many perceived barriers to them using active transport to school.
"So is bag weight one of the modifiable barriers?
"We need a better understanding of the reasons for heavy schoolbags and effective interventions for reducing their weight.''
The latest crop of research findings will be discussed at the Beats Study Symposium 2018 on November 16 from 9am to 3pm at the University School of Physical Education, Sport and Exercise Sciences.
• Register online, or email beats@otago.ac.nz
BRENDA.HARWOOD @thestar.co.nz
Bag weights
• Overall, 68.3% of parents felt their adolescents’ schoolbags were too heavy to carry to school.
• More than half of adolescents felt their schoolbags were too heavy to carry to walk (57.8%) or cycle (65.8%) to school.
• On average, schoolbags weighed 5.6kg (+/- 2.1kg), or about 9.3% of adolescents’ bodyweight.
• Small or underweight adolescents carried bags that were, on average, 15% of their body weight.
• Active transport users were less likely to report heavy schoolbags.
• Actual bag weights did not differ between adolescents who were driven to school and those who walked or cycled.