Thursday, 9 October 2014

Physical activity and fitness levels and autism

Although at present having to be slightly more cautious following some recent surgery (general anaesthetic is awesome by the way!), I normally consider myself to be quite an active person. Through previous discussions on this blog covering topics on the positive effects of walking (see here) and the physical+ benefits of the martial arts (see here) I'd like to think that there are quite a few ways and means that the population at large can easily increase their daily physical activity levels. That physical activity might have quite a few knock-on effects for mental health and wellbeing is another angle to which I subscribe.
"'A storm is coming,' Frank says"

With my autism research blogging hat on, I've talked about how quite a bit of the peer-reviewed literature looking at autism and physical activity levels seems to imply 'more to do' when it comes to decreasing sedentary behaviours and getting people up and active (see here). A recent paper from Kiley Tyler and colleagues [1] (open-access) confirms this assertion.

The Tyler paper in open-access but a few pointers might be useful...

  • Small groups of children and young adults with autism (n=17) and asymptomatic controls (n=12) were included for study and following an assessment looking at diagnostic and developmental factors were investigated using "a series of physical fitness assessments in aerobic fitness, muscular strength, flexibility, and anthropometric measures (height and weight)". We are also told that: "Physical activity was measured through accelerometry".
  • If, like me, measures like aerobic fitness mean very little to you, this particular assessment involved something called the 20-metre multistage shuttle run [2] used to "determine the estimated maximal aerobic power (VO2max) for that individual". Basically, run back and forth across 20m to an ever frequent pinging sound until you can do no more and measure your maximum rate of oxygen consumption. 
  • Muscular strength was measured "using a handgrip strength assessment". Reading about this assessment brought to mind some other autism research in this area which I read about recently from Janet Kern and colleagues [3].
  • Physical activity levels were assessed using an accelerometer worn over 7 days. 
  • Results: well, most of the physical fitness parameters did not significantly differ between the autism and not-autism groups. Strength did come out as reduced in the autism group as per the findings from Kern et al but that's about it. 
  • But... physical activity levels were different between the groups across the various gradings describing sedentary, light and moderate activity levels. "Children with ASD spent less time in light, moderate, and moderate-to-vigorous physical activity and spent more time in sedentary behavior when compared to typically developing peers".
  • The authors conclude that: "more research is needed on the physical activity determinants specific to children with ASD [autism spectrum disorder]". But also that their results were "encouraging as they indicate that children and youth with an ASD show capacity to meet daily guidelines for physical fitness and activity".

So basically, this particular cohort of children and young adults with autism do not lack the capacity to engage in physical activity but for whatever reason, physical activity levels are down compared to those not in receipt of a diagnosis of autism. I should also say that I summarise this without pointing any fingers of blame.

A quick trawl of some of the related research literature in this area provides one or two clues as to what might be influencing those activity levels. Schenkelberg and colleagues [4] talked about features of the social environment potentially influencing physical activity levels of children with autism. It is perhaps an under-appreciated aspect of the social side of autism that solitary play for example, is probably not going to include any great degree of physical activity as compared to what you might see in shared play with peers for example. Schenkelberg et al kinda hint at this with their observation of no significant differences in physical activity levels between their small group with autism vs. asymptomatic controls when engaged in "organized activity".

I mentioned previously that capacity to engage in physical activity did not seem to be affected in the participants of the Tyler study but one should also not assume this is pertinent to all on the autism spectrum. Motor issues have been talked about previously on this blog (see here) and, as per the findings from Christensen and colleagues [5] there is a growing appreciation that an autism diagnosis might increase the risk for conditions potentially affecting motor function: "The higher frequency of ASD in non-spastic than in spastic subtypes of CP [cerebral palsycalls for closer examination". Again, something discussed on this blog before (see here). Rather more speculatively, I'm also minded to point you to a gap in the research base looking at something like comorbidity of Chronic Fatigue Syndrome / Myalgic Encephalomyelitis (CFS / ME) with autism (see here) as another area to potentially investigate.

Physical inactivity is pretty endemic these days across all walks of life. Autism is not unique in its general relationship to relative inactivity although does seem to rank up there when it comes to the available data [6]. Allied to the data on levels of obesity in cases (see here) and the corresponding issues circling things like eating habits for example (see here), there are some important factors to tackle here to ensure that such physical inactivity does not further 'disable' or disadvantage many people who are perhaps already subject to significant health inequality...

Oh, and just in case you were wondering, it's as easy as 10,000 steps [7].

Music then. Fill My Little World by The Feeling.

----------

[1] Tyler K. et al. Physical Activity and Physical Fitness of School-Aged Children and Youth with Autism Spectrum Disorders. Autism Research and Treatment. 2014; Article ID 312163.

[2] Léger LA. et al. The multistage 20 metre shuttle run test for aerobic fitness. J Sports Sci. 1988 Summer;6(2):93-101.

[3] Kern JK. et al. Handgrip strength in autism spectrum disorder compared with controls. J Strength Cond Res. 2013 Aug;27(8):2277-81.

[4] Schenkelberg MA. et al. Social Environmental Influences on Physical Activity of Children With Autism Spectrum Disorders. J Phys Act Health. 2014 Aug 7. [Epub ahead of print]

[5] Christensen D. et al. Prevalence of cerebral palsy, co-occurring autism spectrum disorders, and motor functioning - Autism and Developmental Disabilities Monitoring Network, USA, 2008. Dev Med Child Neurol. 2014 Jan;56(1):59-65.

[6] Mangerud WL. et al. Physical activity in adolescents with psychiatric disorders and in the general population. Child Adolesc Psychiatry Ment Health. 2014 Jan 22;8(1):2.

[7] LaLonde KB. et al. Increasing physical activity in young adults with autism spectrum disorders. Research in Autism Spectrum Disorders. 2014; 8: 1679-1684.

----------

ResearchBlogging.org Tyler, K., MacDonald, M., & Menear, K. (2014). Physical Activity and Physical Fitness of School-Aged Children and Youth with Autism Spectrum Disorders Autism Research and Treatment, 2014, 1-6 DOI: 10.1155/2014/312163