WH&Y authors: Professor Leon Straker

WEBINAR: The Importance of Physical Activity During Adolescence
PRESENTER: Professor Leon Straker
DATE: 27 July 2021




Kate Steinbeck: [00:00:03] Hello, welcome everyone to July's webinar series. We're on a slightly different platform and we’ll change some of the housekeeping rules. But first of all, welcome. And I acknowledge all our institutions and our funders for the WH&Y CRE in Adolescent Health, which supports this programme. I also want to acknowledge the traditional owners of the country throughout Australia and recognise their continuing connection to land waters and culture, and we pay our respects to elders past, present and emerging on whichever lands we are on. 

Kate Steinbeck: [00:00:52] All of you who have taken part in any of our webinars are part of our Community of Practice. This will be an exciting development over the next 12 months where we will become a much more interactive practice. And I encourage you to look at our website up there, to have a look at some of our resources, but certainly coming soon will be some news about how we can be a much more interactive community of research practice in the important area of adolescent health. 

Kate Steinbeck: [00:01:26] Now, during the webinar, everyone's microphone is muted, video is switched off, and slightly different to previously, we just have the chat function, which is up on the top right hand corner, to the left, and I'll ask you to put comments or questions in there, and those questions will be put up at the end of the seminar. So, a slightly different format to last time. But importantly, it's my pleasure to introduce Professor Leon Straker. Leon is a distinguished professor at the John Curtin School of Physiotherapy and Exercise Science. Many of you will be aware of his name as a former scientific director of that very well known Raine Study*, and he's been involved in the longitudinal analysis of behaviour and health data across the teenage decade, particularly in relation to obesity, active and sedentary behaviours, musculoskeletal health and mental health. And so Leon is going to be talking to us today about physical activity, and he's the best person to be doing that. Welcome, Leon. 

Leon Straker: [00:02:46] Thanks very much, Kate. Hello everybody and I'd like to start by acknowledging that Curtin University Perth campus is on the traditional lands of Whadjuk people of the Nyungar Nation and pay respect to their elders past, present and future. I'd also like to say that the presentation today is targeted at the adolescents in the audience and for those adults who are researchers or practitioners or policy makers. I'm hoping there'll be some interesting information for you in your care, research and service for young people from today's seminar. I’d also like to thank the colleagues that have worked with me on the Raine Study project that I'll be presenting later, and then also on a project in a particular school in Perth as well as the researchers on the Active, Healthy Kids Australia, which is a national advocacy group promoting physical activity for young people.

Leon Straker: [00:03:45] The health benefits of physical activity are known to be important for people at all ages, including adolescents, and the benefits include things for improved physical health, better socio emotional wellbeing, better cognitive function and enhanced academic achievement. When we're talking about physical activity, I want to give a few definitions so we're all understanding it to be the same thing. Physical activity is often defined by the type of movement activity that it is, but also by the intensity of that movement. And so that's presented as related to the amount of energy that people expend doing activity, Because different sized bodies use different amounts of energy to perform the same tasks, we tend to make this relative to each individual. So the amount of energy that you expend while you're lying down resting is called one MET (metabolic equivalent of task). And so we define sedentary physical activity as being less than one and a half times the amount of energy you spend while you are lying down resting, so that would include things like sitting and reading. Then, there is light activity, which is less than three METS, which are things like walking and doing easy house chores. Moderate activity, which is less than six times the amount of energy you spend when you are resting, things like brisk walking or mowing the lawn. And vigorous physical activity, which is more than six METS, are things like running and shoveling. And because you don't have a MET meter on you when you're moving, then to make that sort of easy to work out, when you're doing light activity, you can continue the conversation quite easily, but when you're doing vigorous activity, you can't make a whole long sentence. 

Leon Straker: [00:05:30] In addition to the intensity level, physical activity is often defined by the purpose or the domain of that activity. And so the first one people think of when they think about physical activity is organised activity like sport. But actually a really important type of physical activity for young people in particular is freeplay. Another important type of physical activity is transport, and that will be commuting to school or to the shops and things like that. Physical activity in daily life can also be important, and that's doing chores. Then there's occupational physical activity and the occupation for most adolescents is a student, and so studying is part of that sedentary activity often when you're sitting down. But they may also be performing part-time jobs and that may be more physically demanding. Looking at the contribution of the different kinds of physical activity for young people in Australia using national data, you can see in this pie-chart that leisure time physical activity from both sport and freeplay are really important, transport, walking or using a bike are smaller components and chores are an even smaller component.

Leon Straker: [00:06:36] There are guidelines in most countries now for the amount of physical activity that should be aimed for by young people, and Australia has these guidelines as well. And so the headline guideline is that young people should accumulate at least 60 minutes of moderate to vigorous intensity physical activity every day. An expansion of this is added - that for additional health benefits, young people should engage in more physical activity, up to several hours per day for additional health benefits. So that's about the amount and intensity. Another guideline is talking about variety and suggesting that a variety of aerobic activity should be undertaken, including some physical activities that are vigorous in intensity. And the final one here, that different types of activity should be undertaken, so physical activities that strengthen muscles and bones should be included at least three times a week. So this is more resistance type exercise where you're lifting a body weight or pushing against something hard to build muscles and bones. What's missing from the physical activity guidelines for young people in Australia is something that the guidelines for older people have, and that's that we should be doing some activity that enhances balance and coordination. 

Leon Straker: [00:07:50] There are also guidelines in Australia and internationally about the sedentary end of activities, so sedentary behaviour guidelines, and these guidelines say to minimise time spent sedentary every day and to break up long periods of sitting as much as possible. And a lot of the prior research is focused on screen time with young people in particular. And so there's a guideline to suggest limiting screen time for entertainment purposes to no more than two hours per day. So these are the guidelines that Australia and many countries have to suggest what is the appropriate amount and type of physical activity young people should be engaged in. 

Leon Straker: [00:08:26] Let's just have a look at that as a whole of the population of Australia and young people, how are we doing? The Australian Active Healthy Kids Australia does a report card every few years that collates all the available data on young people in Australia and gives the nation a report card, much like a child gets a report card at school. And you can see for the two indicators of overall physical activity levels and for screen time, Australia has consistently been scoring a D minus, which suggests that less than a third of young people in Australia are actually meeting these guidelines. And that's despite us doing quite well in the proportion of young people doing organised sport and physical activity, we get a B minus as a nation for that. 

Leon Straker: [00:09:12] So let's just have a look at what happens with meeting guidelines over time. So this graph on the horizontal axis shows young people from young children two to four years of age through to adolescence, 17 years of age. And on the horizontal axis is the proportion of that age group that are meeting the physical activity, moderate, vigorous activity guidelines. And you can see that the proportion of the population meeting those guidelines decreases over time. And adolescence is clearly a problematic time for people to be making the guidelines.

Leon Straker: [00:09:47] In terms of sports participation, adolescence is also an issue. So this graph shows age groups again, but this time from four right through to older than 85, and the proportion of people that are regularly engaged in sports activity and you can see that during younger childhood periods there is quite a high proportion of Australian children that are engaged in sports. But during the adolescent period highlighted here, it's dropped dramatically and falls as people go into young adulthood. And it's very low all the way through adulthood until kicking up until we're 75, so this is a chance for us in the future. 

Leon Straker: [00:10:27] This is a similar graph on the proportion of the Australian children and young people meeting screen time guidelines, and over this adolescent period, again, you can see that there's been a lower level of the Australian population meeting those guidelines. So all of the data we've looked at so far is treating all Australian young people as belonging to the same group. But actually we have some knowledge that not every young person in Australia follows the same pathway in terms of participation in physical activity over their childhood, adolescence and into adulthood. But to actually understand how those pathways go, we need to have data from the same people over a long period of time. So we need a very special type of study to do that. We're very fortunate in Australia to have access to a study called the Raine Study, which has followed several thousand families from when the young people were 18 week old fetuses in their mother's womb, up until now where they are 30 years of age. And using data that's being collected at regular time points from these families, we've been able to look at their participation in physical activity, sports and sedentary behaviour and how that relates to their health outcomes as either late adolescents or as young adults. 

Leon Straker: [00:11:43] So I'm going to show you three different trajectory analyses that were done and these are going to be about physical activity, sports participation and TV viewing. So this graph on the horizontal axis is the age of the young people from eight years of age through to 17 years of age and on the vertical axis is how relatively active they were compared to their peers. So parents were asked to report whether their child or adolescents were less active than their peers, about the same or more active than their peers. And some of those people that I mentioned in the acknowledgments early on are very competent in doing advanced statistical analysis that I can't do and can create groups of individuals that follow the same sort of pathway in terms of their physical activity across childhood and adolescence. When it comes to this very crude measure about relative physical activity to their peers, you can see there's three groups here, there's this blue group, which is repeatedly less active than their peers, the green group that's about equally active as their peers, and the red group that's relatively more active than their peers. But there isn't a change between the groups over time, people seem to stay in the same relative position to their peers, acknowledging that overall all of the age group, all the adolescents, are doing less activity as a whole. 

Leon Straker: [00:13:07] If we look at sports participation, though, the trajectory, or the pathways that people follow over childhood and adolescence are actually a lot more interesting. So this graph on the horizontal axis, you can see it goes from five years through to 17 years of age, and on the vertical axis is the proportion of young people participating regularly in sports. This is just looking at females to start with. The red line shows those that are regularly, consistently participating in sports. The blue line shows those that are not participating in sports. And then you've got this green line where they had a high percentage participating in sports early on and then dropped out of sports in adolescence. So that's clearly a group that we are concerned about, that they were physically active through sports participation as a child but coming into adulthood, they have dropped out of that participation. There are some quite interesting similarities, but also differences when we look at what's happened to the males over this age, same age group, five to 17, and we have the red group again, which are consistently participating in sports, but we don't have the blue group as not participating at any time. But we have a blue group who weren't participating at the beginning, but have joined in the sports later across childhood and adolescence. And then we also have this green group who were participating in sports in childhood, but in adolescence dropped out. 

Leon Straker: [00:14:41] Lastly, we're looking at the trajectories this time of the age groups going from five all the way through to 20 years of age and how much TV they were watching over that time. And we have this red group that was consistently watching lower levels of TV, the blue group that was consistently watching high levels of TV. And then you've got this green group that had an increasing amount of TV viewing through adolescence compared to watching a low level of TV during childhood. So that's really interesting, but one of the things to watch out for in this place is that this data was collected in the first decade of this century. And we know that there's been substantial changes, particularly in screen technology in the first and second decades of this century. So adolescence actually may not be watching TV anymore, but they may be using mobile touchscreen devices like phones, tablets and laptop computers. 

Leon Straker: [00:15:36] So I'd just like to show you some trajectories of screen use that was taken a decade after this. In a school with a bring-your-own-device policy. This graph goes through from year five to year 12, so that's about 10 year olds on the left through to 17 year olds on the right. And the vertical axis is the amount of time spent using different types of screens, so the dark line is the combination of all the different types of screens. And if you look over at adolescence, there are some really interesting things happening with different types of screens. And so you can see this green dotted line here was quite high during primary school and the first part of high school but in the transition from year nine through to the senior years, you can see that the use of tablet computers declines and it's replaced by this purple line, which is laptop computers. And if we just look at that yellow line there, that's mobile phone use and you can see that that's pretty much increased over age groups all the way through to the end with a slight drop off in year 12. But actually, it's even more interesting than that, because if you break that down by males and females, females actually reduce the amount of time they spend on mobile phones substantially in year 12 compared to year 11, whereas in males there isn't a great reduction in that. This was a survey and we did some qualitative work following this up to try to work out why this was happening, and what the girls were telling us is that they reduced using social media during year 12 to focus on academic studies, and what the boys told us was that they increased their social media use during year 12, but actually their social media use was targeted towards their schoolwork, asking what assignment was I supposed to be doing? Where do I find that resource that they talked about? So it was quite interesting to see they were not just time differences, but also gender differences in how screens are being used. 

Leon Straker: [00:17:38] But going back to the Raine Study now and looking through those different trajectories which follow the pathways that different groups of young people in the Raine Study followed over childhood into adolescence. So this was the first set of trajectories that we looked at a few minutes ago talking about relative physical activity. We're able to look at those three groups and look at different measures of physical and mental health and cognitive function as young adults. And so the adolescents and young people in that red group who are consistently more active had lower body fat, the males had lower systolic blood pressure, both males and females had less other health disorders, they had better mental health self ratings, in males they had lower depression symptoms, and both males and females had better cognitive function as measured by reaction tasks. So you can see across this whole pathway from childhood to adolescence, consistently being physically active in the Raine Study was related to better physical and mental health and cognitive function like it has been in other less longitudinal studies. 

Leon Straker: [00:18:48] Looking at those trajectories for sports participation, those red groups of more consistent participation and the purple group in the boys where they joined sports participation as adolescents, those groups had more lean body mass and had better physical health self ratings, and that group in green who dropped out from sports from childhood through into adolescence, had higher levels of depression symptoms. So sports participation was related to beneficial outcomes in terms of health for males and females across that time period. 

Leon Straker: [00:19:25] Lastly, looking at TV viewing trajectories, those young people in the groups that had lower levels of TV had lower body fat, but it wasn't related to differences in depression or anxiety or stress symptoms, but it was related to having better bones, stronger bones.

Leon Straker: [00:19:49] So we've seen this graph before, that moderate and vigorous physical activity over adolescence declined, and what we’d really like to do at a population level is to reverse that decline, to have the whole population sort of more physically active. So more young people are getting the benefits of being regularly physically active. But what you've just seen from those trajectory studies is that we can't look at young people as all following the same pathway through childhood and adolescence and that we need to look at the different pathways that they're following and try to provide support and information for the different sorts of issues that those different groups of people are having. 

Leon Straker: [00:20:30] One of the things that we need to consider at a community level is risk. This is data that's drawn from the UK but reimagined in a small river town on the Murray River in South Australia. And a great-grandfather who would be eight years old in 1919 was able to walk within a 10 kilometer radius of their house, back then, a grandfather aged 10 in about 1950, was allowed to explore up to five kilometers away from home along the Murray River. The son who was aged eight in 1970, was allowed to walk to the local creek two and a half kilometers away. And yet his son, who is now aged eight, is only allowed to walk on his own to the end of his own street, which is less than a kilometer away. So we have this reducing roam area where as a community and as parents, we are comfortable to let young people wander unattended on their own. And that's restricting the amount of movement and physical activity that they might be getting. And we can see a similar sort of related aspect to that in the proportion of children who are transported to school in an active way. So that's either by bike or walking or scootering. And this is data highlighted from Australia and a few other countries from back in 1970 right through to the last decade. And you can see the steady decline in the proportion of young people getting to school in an active manner. So in 1970 it was about two thirds of Australian children, and now it's down to about a third of Australian children. When we talk to families about why that's the case, the dangers of traffic and the risks associated with traffic are often the reasons cited, and yet, if you cycle, drive or walk past a school during school holidays, there's hardly any traffic. So we have a sort of vicious circle happening where people are worried about traffic so they drive to school and that creates the traffic that makes them worried about the traffic. But this is an issue of risk and acceptance of risk and what's the risk benefit for letting children to be more active and independent in moving around in the neighborhood to school?

Leon Straker: [00:22:54] Second area I'd like to talk about with this is movement skills and a potential risk that this creates for young people. So as babies, we all start with reflex movements and through infancy and childhood we develop some rudimentary movements, reaching, grasping, crawling, standing, walking, and then across childhood and into adolescence, we develop fundamental movement skills about being able to run, kick, stand, ride a bike, swim, those sorts of things. And we may develop some specialised movement skills as well, for example, how to play tennis or how to do backstroke or how you lift weights in a squat movement. And as we acquire those skills, we're giving ourselves different choice abilities of what we're going to do across our whole lifespan, and childhood and adolescence is a really key time in developing these skills so that as adults, you've got options about what you can do in terms of being physically active. 

Leon Straker: [00:23:51] And there's a risk here for adolescents, so if we have a look at this graph here, this is the proportion of Australian children in grade six, so that's about 11-year- old preteens, with girls in dark blue and boys in light blue, and different sorts of skills along the bottom there. And you can see that overall, less than half of Australian children coming into adolescence have actually got some fairly basic skills that will enable them to do a variety of physical activities as an adolescent and through their whole life. So the ability to sprint, to jump vertically, to side gallop, to leap, to kick, to throw, and to catch varies with the skill. But on the whole, less than half of Australian teenagers come into adolescence with this skill level and therefore the ability to be able to participate in various types of activity. 

Leon Straker: [00:24:53] While, I was preparing this talk a couple of weeks ago, I was watching the Tour de France and the cycling and a West Australian won one of the stages, Ben O'Connor, and what was interesting about the commentary on that day and several other days is that the commentators were saying that it was obvious to them that some of the riders, and these are elite professional cyclists obviously in the Tour de France, some of them hadn't been cyclists as young people, that they had come to the sport late, and the commentators were saying that they could pick the people who had come late to the sport and hadn't been cyclists as children and adolescents because they didn't have the same level of skill. So they were really highlighting that adolescence is this key period for young people to develop a whole range of skills to enable them to be active throughout life. Now, I'm not particularly interested in elite sport, I'm a bit ambivalent about the effect that it has at a population level, what I am really interested in, though, is at a population level whether everybody is comfortable, has some basic skills to be able to do physical activity in their normal life. And so this picture about people just commuting to work and being comfortable and confident in cycling to work, if they hadn't been riding a bike and had that experience as a young person, they may not have the confidence as an adult, and so that option for them as a way of being physically active throughout their whole life may not be available to them if they weren't able to develop those skills as a young person. 

Leon Straker: [00:26:30] So, I have a few tips for adolescents on how to be physically active, and the first three are fairly traditional and things that you might have seen elsewhere, but I think are really important for encouraging sustainable physical activity by young people. The first one is to do activities that you enjoy, and it speaks for itself. The second thing is to make activities social, so link up with friends or with family to do your physical activity. The third thing is a bit harder, and that's choosing an active way if it's an option, so look for active opportunities. So rather than just standing still on the travelator after the supermarket, then actually walk up while the travelator is going. But this is difficult because it's against our genes, we're programmed to conserve energy and not use energy, and so creating opportunities for physical activity is something that actually needs to be going against what your evolutionary development has done for you.

Leon Straker: [00:27:32] There are two other ideas that I've got that will seem a bit strange, perhaps at first. There's a lot of talk about young people should use less screen technology but actually I'm encouraging young people to use screen technology, but use it to promote their physical activity. So use it to organise their social aspect of their activity, so messaging their friends to get together to be physically active, for example. Using it to increase their enjoyment in the same way, so having music going while you're being physically active or if you're into numbers, then tracking the kilometers that you've run, the weights that you've lifted, the time of the laps you've done in swimming, this can increase enjoyment for you. And then lastly, using technology to get ideas about how you can be physically active. And that's been evident across the world over this last 18 months with COVID where people have had more restrictions on where they could be physically active and how, and a lot of people have really benefited from going online and getting some good ideas about how they could be physically active. 

Leon Straker: [00:28:38] And the idea I would like to finish with is the idea of risk. Young people are often told to not take risks, and I'd like to counter this and suggest that young people should be taking the appropriate types of risks. So I'd encourage young people to try new things and to fail. I don't mind if young people lose a bit of skin and get a few bruises when they're trying things and fall off or fall over or get skinned. Teenage bodies repair very quickly luckily, and this is a great time to be trying things and failing and challenging your body and brain so that your body and brain actually builds to be stronger and better. So during adolescence, we all know that's a time when your body is growing rapidly and your brain as well. If you challenge it in terms of the physical stresses and the complexity of the movement and the coordination required then both your body's capability in terms of musculoskeletal sense, the muscle bones, but also in a brain to body connection sense the neuromuscular component of your coordination will improve as well. And adolescence is a really good time to work out what you like and don't like in terms of physical activity, and perhaps one of the key aspects during adolescence in a time when young people are wanting to take more control over their lives and what they're doing, what they do in terms of physical activity can be something that they can take control over and take on that leadership for themselves on.

Leon Straker: [00:30:08] In conclusion, physical activity is critical for healthy development over adolescence. It's something that adolescents can control for themselves and it can help with many of the issues that arise for young people during this period of change. So adolescence is the time to build good bodies and good brains and to learn lifelong skills to enable lifelong activity and participation. For those that are interested, the references that are cited during the slides are in the list there. And I'd like to finish by thanking you very much. Thanks.

Kate Steinbeck: [00:30:42] Thank you, Leon, for a fantastic presentation. There are lots of questions, but I think you've really given us a really clear explanation for the fact that we're probably not thinking about physical activity in a nuanced and complex form and that probably makes the guidelines seem rather naive at the best of times, because just telling someone to do moderate activity always seems to me a little bit of a problem, because often the young people I speak to have no idea what I might mean by that. So I'm actually going to ask the first question, because I'd like to just chat about the guidelines briefly. How do you think our guidelines for physical activity could be improved for adolescence, and do they really have any empirical basis? 

Leon Straker: [00:31:51] OK, short answer, yes they could be improved and there is some empirical basis. The long answer is I think what would be really useful in terms of the development of guidelines is greater involvement of young people in doing that. So guidelines are generally done by people like myself who can vaguely remember adolescence in a previous century in a very different world. And so I think involving young people in how that messaging is given and what sort of advice is important for people, I think would be really important. And we've had an example of that with the screen time guidelines that have been revised over the last couple of years in Australia. Lots of the evidence base for that was from TV use in the previous century, rather than being about mobile touchscreen device use as what screen use is now for teenagers. TV forms a very limited part of screen use for most teenagers in Australia now, and it's their phones and mainly tablets or laptops that they're probably using at school as the secondary use. And so actually having better information about that across the broad spectrum of health issues, there's been quite a focus on screen use on mental health, which is appropriate. But all the sedentary things also related to physical health, and whether you're reading a book on a screen or reading a book from paper probably doesn't have any physical difference on your effect and yet we demonise reading on a screen and glorify reading from paper, yet its cognitive benefit and its physical harm are probably equal. And so having better contemporary evidence about what contemporary practices are by young people, both in terms of screen use, but also in terms of what sort of physical activities they do. In Australia, we are fairly hung up on sports and that's particularly evident in this current couple of weeks at the moment with the Olympics going on. And you saw from that national report card earlier that actually Australia does pretty well in terms of having kids involved in sport. But then you saw that graph that showed what happened after childhood and through life, that we have this huge drop off in sports participation. And so getting that transition for young people to be able to go from things they enjoyed as a child to things that they're going to enjoy as a young adult that they can keep on going through with life, I don't think we do very well with yet. And so potentially finding better examples of practical things that young people can do to be physically active that are a bit different to what we've regularly told them to do, I think is going to be very important. 

Kate Steinbeck: [00:34:47] Thank you. And, Leon, I'm going to continue that. We've got a question from Paris: “How frequently do they review the guidelines, given these differences that you've talked about?”

Leon Straker: [00:35:04] The guidelines in Australia are put out by the federal health department and from memory the ones for young people and children lasted for about 10 years before they were revised. And it's usually something like a two-year process for the revision of them. And then the evidence base they're looking at for that is probably a year or two old by the time it is revised. And so it's probably sort of as soon as the guidelines come out, they're probably looking at four or five year old data as their basis, as the most recent evidence, and so particularly in this last decade, that's been really important with the change in technology for screen stuff, in particular, the sort of physical activity lifestyle of Australian children probably haven't changed so dramatically, but the screen stuff has really changed dramatically since iPhones came out in 2007 and iPads in 2010, and widespread broadband access to be connected anywhere, any time is really different now. 

Kate Steinbeck: [00:36:11] Thank you. The next question is: "Do you have any recommendations for resources for adolescents?"

Leon Straker: [00:36:24] I haven't, but actually I've been working with the Raising Children Network, which has very good resources for parenting, and the project we've been doing with them is at the other end of childhood for very young children. They've got some excellent resources for children before school and during primary school age. I haven't actually had a look at whether they've got resources for teenagers, but that would be the first place I would look at as a place that has very good practical, evidence-based information that's appropriate for an Australian setting. 

Kate Steinbeck: [00:37:00] Actually, just following on from that, it's more a comment than a question from Kay, who says: "Who did the guidelines target? For young people I know they wouldn't know about them unless it was part of a school assignment." 

Leon Straker: [00:37:16] Yes, and I think that comes back to the messaging and what message and how we distribute that. I can totally understand because what ordinary person is going to be going to a health department website and looking up guidelines for that. And so there are a number of mechanisms and where we traditionally try to get information through to young people and schools are an important component in that. But there are probably a lot of other ways we could be getting messaging to young people rather than making it part of a school curriculum assignment, to actually make it meaningful in their day-to-day lives. 

Kate Steinbeck: [00:37:57] Next question from Rachel: "I missed whether there were differences between genders and it would be good to go over that because I think there were some very key points there. Do social expectations and pressures have an impact on the differences between male and female adolescents in skills for physical activity throughout life?" 

Leon Straker: [00:38:28] I presume, Rachel, that you're talking about the graph that was talking about the proportion of preteens that could do various types of skills. And there are very large differences in males and females for some types of skills, and they are particularly around what's called object oriented. So catching, kicking and throwing, there are quite differences in those. There is a higher proportion of boys having that skill than girls compared to the sort of sideways skipping type movements where more girls can do that than boys. And if you look at playgrounds of 15 years ago, then that makes sense. I think one of the positive things that's happened in Australia in the last decade has been the rise of both boys and girls playing a lot of organised sports, things like cricket and Australian Rules Football. Coming from Western Australia they're the sort of two main football codes, summer and winter sports. And so, although I’m a bit ambivalent about elite sport, the encouragement of females to do those sorts of sports, I would expect that there's going to be a better uptake in those sports through childhood. And so the next time we look at some of those movement skills in sort of five years time, I would expect those gender differences to be lessened because more girls are going into cricket and football codes, and so having the kicking and catching and throwing object skills. I haven't seen too many more boys doing skipping type things, but maybe with breakdancing or some sort of dance type activities being acceptable for boys now where it wasn't sort of 50 years ago so much that might help with that as well. 

Kate Steinbeck: [00:40:18] Do you think, Leon, there are social pressures or do you think it's the effect of puberty on body shape and size? Do you think that has an impact on girls dropping out of sport? 

Leon Straker: [00:40:35] I think there’s likely to be a range of issues. This is not something that we've researched specifically, but I think it would be really valuable to look at that. There are social expectations, body image issues. In the past, there's been the issue about what range of sports are acceptable and offered to girls versus boys. And so what I was just saying there is that the range is expanding I think for girls but there's still quite a large focus on team organised sports rather than other sorts of things that could go through life, both for boys and girls. And that drop off that you saw from adolescence to adulthood with sports participation is something that some sporting bodies in Australia are quite cognizant about and they're really trying to expand the common perception of sport being something not just about a team sport, but things like bushwalking, for example, which we don't traditionally think of as sport, but Sport Australia is sort of looking at that as something that they're wanting to try to promote because they can see that it is something that people continue throughout life. Australian Rules Football is not something that I can do easily at my age now, even though I enjoyed it as a young person. And so trying to find activities that aren't necessarily the ones that were traditionally done with young people but are more lifelong capacity, skill development, the things people can continue to do throughout their life, I think will be really useful for both males and females. 

Kate Steinbeck: [00:42:04] Thank you. Now, the next question is quite topical from Sharon and Sharon asks: "Are there any tips for vigorous lockdown activities in a small yard or inside?" which I think is really important as we see the mood and well-being of young people really dramatically decreasing over the last year.

Leon Straker: [00:42:31] Being restrained within a room or a house or a small radius around a building is what we do when people have done something bad in society and we restrict their movement. And so that's happening to large groups of populations in Australia and internationally for prolonged periods of time with pretty clear impacts on their physical and mental health directly. And that's for all age groups and particularly across adolescence. And so one of the things I think is being talked about has been quite successful for young people is to actually use screen technology to not only maintain their social relationships, because that's a really important period for them when they're transitioning away from family support to peer support. And even if you can't go and visit your friends, you can still have that social contact with them. It's clearly important for their educational outcomes to be doing school virtually by screens, but also to be looking for ideas about what you can do within a two by one metre block, if that's the space that you've got in your bedroom or front yard or something. And there's some really great videos and streams of output by people with aerobic and resistance-type exercises, flexibility type exercises that people can do running off their screen to give them an idea and something to stimulate them to do. So if it's going to be going for several weeks like it has been in several states of Australia, and looks like it's going to continue to be for at least one state in Australia for a while, then actually having something that has a progression over a few weeks and that you set some goals and try to achieve those goals over a few weeks, that's another way that young people can look for some great ideas and take control themselves in a situation where lots of people think that they have lost control because they're being restricted in their movement, but actually take control about what you do, how you use your time and feel and see the benefits in what you do in terms of how you feel physically and mentally. 

Kate Steinbeck: [00:44:32] Thank you, those are really useful tips and comes back to knowing where to find those things, too. I think for young people it would be good if they could perhaps better understand where they could go and look, although they should be pretty good at searching YouTube, because that's what I guess all of us do to answer our questions. Now, I've got another question from Carla: “Has research identified young carers and the impact of their commitments on physical activity and health?" 

Leon Straker: [00:45:21] It's a great question Carla, I don't know, is the short answer. There's a lot of interest in what happens in the transition from being a child to being an adult and taking on adult responsibilities and that might well be parenting as well. From anecdotal information and observation, you can see that it really does change the capacity and the ability of young people to be able to do physical activity. And so that may well be a particular subgroup that would benefit from having some really good understanding about what is happening for them, what are their challenges and what sort of supports and resources could actually help them to try to maintain physical activity when they're entering into parenthood a bit younger than their peers, perhaps, and without the normal sort of social supports around them in that period of time. 

Kate Steinbeck: [00:46:12] The questions keep coming. This one's from Annabel, who thanks you for the presentation and wondering if you had any thoughts on the balance between physical activity and risk of harm for adolescents. She's particularly named rugby and risk of head injury: ”Should we be encouraging all forms of sport with some of the current concerns emerging on long-term impact of head injury?

Leon Straker: [00:46:43] Yep, I think that's a great question. And I'm speaking to people in New South Wales and some rugby dominated states, so I need to be careful what I say. But I'll be blunt about it. I don't really mind if kids get scratches, bruises, even broken bones. Young people heal really well. And as long as the fracture doesn't go through a joint that's not compound, then it's all going to be good. And it gives them a nice story to talk about as they are growing up. What I am really concerned about is head injury. So I would have real concerns as a parent and as a physical activity advocate for sports that have head-injury risk. And so that's the combat sports, but also some of the codes like rugby. And try to imagine yourself if you hadn't watched those sorts of games growing up through your life and you're an alien coming in and you turn on the TV and saw a rugby game and saw these very substantial people developing high accelerations, high movement velocity and large mass colliding with each other, it would be tough to think that that was actually a sensible thing to be encouraging people to do. I think. 

Kate Steinbeck: [00:48:06] Very challenging answer to our rugby fanatics. They're still coming in. The next question again relates to team sport, and it's from Catherine who says: "I find there is very little opportunity for teens to enter a sports club, it seems they have opportunity to learn skills for sport in primary school but some clubs aren't interested in teenage beginners."

Leon Straker: [00:48:34] So I think this is a great observation and it's a fundamental problem with a lot of our team sports, as Catherine said. And I think it really inhibits a whole lot of really interesting exploration for teenagers to be able to take up a new sport. And so I was encouraging adolescents to take up new sports, but actually they may well find barriers to that with particular clubs not being interested in taking on somebody who hasn't had that expertise before. Because like I was saying with cycling, if you're coming into a team sport as a 15 year old and you haven't been doing it for 10 years, their understanding about the strategic gameplay is not going to be at the same level for somebody who's been doing it for 10 years. You may well have the fitness, you might be able to develop the strength and the speed, even to some extent these object handling skills or the particular movement skills that you need but it may well be the cognitive understanding about just how game strategy and things work that is more difficult to pick up. So I think it's something the sporting organisations can really look at and that they can think about having a feeder pathway for people who are interested in trying a sport, even though they've got no background in it, because they may well pick up some really good things. And this is a sort of flippant example, if you like. The Tour de France stuff, some of the people who won stages in the Tour de France had been runners up until a few years ago and had some issues with running and switched over to cycling. And so people can perform at elite level if they are coming in late, even though they don't have all of those things. So that would be a great thing for sporting organisations to look into. 

Kate Steinbeck: [00:50:19] That's a fascinating observation, but it still says something, there's something about the teenage brain that we should protect in sport but also make good use of it, continuing to learn skills that were probably not at their maximum at primary school. Now, the next question, I've got so many questions coming through Leon, I am keeping an eye on the time. This question comes from Michael. And again, thanking you for a really informative talk, which it certainly was. And he's talking about risk, two things. I think it's more a comment on risk that we're becoming more fearful of any risk. And I think that probably is a true observation. But he also asked: "Are there any insights into the correlation of how good urban planning contributes to rates of physical activity?" 

Leon Straker: [00:51:29] Sure, one of the nice things about adolescence is that it's this huge period of opportunity, partly because their body and brain is rebuilding itself so rapidly and so quickly that it can respond to challenges in a way that an older body can't. And so you really get a benefit for trying something new as a young person where it's really hard work once you're over 20, I'm afraid. In terms of urban planning, look we all think that that's really important, and Australia does very well in most areas for the amount of green space and the facilities for physical activity. But we tend to take those green spaces for granted and not actually use them and activate them, and so I really support the use of good urban planning to encourage physical activity in green spaces. One of the areas that Australia lags behind in is active transport to and from work. And the photo I showed earlier about people cycling to work was from Copenhagen, you can probably pick that by that building in the background, but the facilities there compared to the facilities in capital cities in Australia in particular. To make safe cycling to and from work, we're not talking about elite athletes, we're not talking about Lycra, we're talking about just getting to and from work in a efficient way that helps your body and brain, helps the planet at the same time, has all these great benefits and all you really need is a dedicated lane and a bit of a barrier between you and two tons of metal coming past 60 kilometers an hour. And so I think that's the area where there can be great advances in Australia, in terms of enabling young people of every age to be out moving around more as our population increases, as people living in cities increases. Getting around by cars just isn't sensible anymore, you get gridlock, but actually getting around by bike, by walking, by scootering is a sensible way. So I think we can do quite a lot with that. In terms of green spaces, I think we probably need to talk to young people about why they don't bother going there. And in what I've seen in terms of information coming through from young people is that potentially we can use technology to activate those green spaces to be something that's more than is there and make it something that is enjoyable and interesting and desirable for them rather than as a community, us thinking, well they’ve got a square kilometer of green lawn there why don't they go and be active? And I think they probably need a bit more encouragement of that. 

Kate Steinbeck: [00:54:20] This next question follows on a little bit from that, because the significant barriers that exist for young people to access organised sport include cost and also ability and parent engagement or commitment. Are there any resources to promote the importance of involvement to parents and also funding opportunities for the individual? 

Leon Straker: [00:54:49] This is a really good comment. And as with all things in life, the resources that your parents provide for you both in their time, their finances and their engagement and commitment are really essential, really beneficial for young people, but unfortunately are not universally available to young people. And so there are good parenting sites like the Raising Children Network I mentioned before, which does give good information to parents that encourages them to be actively engaged with their children, to model physical activity, to engage and encourage physical activity. That's great. A lot of the sports codes have done quite a lot over the last couple of decades in terms of training for parents in what's an appropriate way to behave when your child is participating in a sport in front of you. And you may well have all seen some good examples of that inappropriate behaviour by parents on this on the sidelines. But a lot of the codes have done quite a good job over the last couple of decades to improve that. In terms of funding opportunities, there are different schemes available to try to support covering the cost of participating in the sport, for example, and local councils, local sporting organisations, some government grants are also available but they come and go, and they vary from place to place. But there are some opportunities there. But again, you know, it takes some effort to try to track down what those opportunities are. So how do we make it apparent to adolescents what the opportunities are if their parents haven't got the time or they're both working, haven't got the capacity to actually assist them, haven't got the finances? How can a young person find out where those resources are to enable them to take control and do the sport that they'd like to do even if the sign up fee is $200 or whatever? 

Kate Steinbeck: [00:56:45] I think we're almost out of time, questions keep coming in, but I'm going to make this the last one, and this is from Michelle: "Do you think uniform plays a role in the gender differences with often teen girls uniforms not ideal for lunchtime physical activities, just only scheduled sport in their special sports uniform?”

Leon Straker: [00:57:11] Yeah, and this is a great comment. And there's been a bit of discussion in the news media this week by elite female athletes being chastised by judges within a sporting event in the UK for not wearing appropriate clothing. And other elite athletes complaining about the sports organisation rules about the clothing they should wear. And I echo the words of the elite athlete who was saying that female athletes should be able to wear clothes that they feel comfortable being active in, and whether that's elite or anybody or at school, the clothes need to be appropriate. If you look historically, we've made women wear long dresses and bustles and corsets and expect them to play tennis and stuff like that. And that just looks laughable now. But to some extent, some of those restrictions still apply in terms of the rules around clothing for males and females in sports, they just don't seem to be fair, but they should be about enabling the participant to feel comfortable and to be able to do the sport. 

Kate Steinbeck: [00:58:19] Well, I think it's time to wrap up Question Time, Leon, thank you for your expertise and obviously a fascinating talk, which was so interesting to the whole audience. I thank everyone who attended today and remind you that this session has been recorded as well. Leon, our thanks again. 

Leon Straker: [00:58:41] Thanks, everyone. Bye bye. 

* The Raine Study is named after Mrs Mary Raine, who was a self-made hospitality and real estate mogul in Perth. She established the Raine Medical Research Foundation, which funded and continues to fund the Raine Study.

About The Authors


Leon Straker is a John Curtin Distinguished Professor of Physiotherapy, focussed on adolescent behav...