Exercise as it relates to Disease/Does the context of physical activity have an effect on mental health in early adulthood?
The following is a critique of the research paper The longitudinal association between the context of physical activity and mental health in early adulthood by Doré et al. (2018)
What is the background to this research?
Physical activity (PA) has been shown to be effective at promoting positive mental health and reducing depression and anxiety in young adults.    Studies have also shown that higher intensity and PA frequency are associated with increased mental health benefits.   Leisure time PA has also been shown to be more strongly associated with mental health outcomes.   This study aimed to build on this knowledge and the authors hypothesised that either social connectedness or PA volume were mediators of these mental health benefits. The authors examined this relationship in the hopes of better informing future public health programs and policy as currently the Canadian PA guidelines only state the amount of PA one should complete and do not suggest a context in which PA should be completed which could possibly help optimize mental health outcomes. 
This study is important as in Canada the country this study was completed in it is estimated that 10-20% of Canadian youth are affected by a mental illness or disorder and surpassed only by injuries, mental disorders in youth are ranked as the second highest hospital care expenditure in Canada. 
Where is the research from?
This study was conducted in Quebec, Canada at the College of General and Professional Education de l’Outaouais. The main author of the study Isabelle Doré is an Assistant professor at the School of Kinesiology and Physical Activity Sciences, Université de Montréal. She has been an author on multiple journal articles relating to the relationship between mental health and exercise in both youth and adults.
This study was funded by doctoral awards from the 4P Strategic Training Program. It is unlikely there is any bias arising from this funding as the groups that provided funding do not stand to make any profit from services related to mental health or exercise.
What kind of research was this?
This was a longitudinal study which is a type of observational study which means the researchers collect information about the subjects without interfering with them. Compared to a cross-sectional study which only collects data at one time point a longitudinal study collects data over multiple time points and is able to measure change in variables over this time period.
What did the research involve?
This study involved baseline data being collected in compulsory physical education classes at the College of General and Professional Education de l’Outaouais in October 2013. 1527 students completed questionnaires during class time and provided contact details for follow up. Of the 1527 students only 460 completed the questionnaires online for follow up 6 months after initial data collection. This follow up response was quite small and the authors acknowledge that it is most likely due to the students originally completing the questionnaires in a compulsory class and the follow up being contact by email and non-compulsory to complete.
There were multiple measures used for this study, firstly PA context was distinguished between (i) team sports (ii) informal group PA and (iii) individual PA. Positive mental health was measured using the Mental Health Continuum-Short Form (MHC-SF) questionnaire which comprises 14 items that measure psychological emotional and social well-being. Anxiety symptoms and depressive symptoms were measured using the Hospital Anxiety and Depressive Scale (HADS). Social connectedness in PA was measured using The Relatedness to Others in Physical Activity Scale (ROPAS) which assesses perceived relatedness to others in leisure-time PA, regardless of PA context. PA Volume was estimated in metabolic equivalents (METs) for all participants using the Godin-Shephard Leisure-Time Physical Activity Questionnaire (GSLTPAQ).
All data collected during this study relied on self-report measures which can be inaccurate especially for physical activity as it has been shown that participants are likely to both over and underestimate their actual physical activity levels. All subjects in this study were college students and it has been suggested that due to college students being a very specific population it is sometimes hard to generalize findings from studies containing just college students to the general public but the researchers do acknowledge both of these limitations.
What were the basic results?
- PA in informal group and team sports was found to be associated with higher positive mental health scores, fewer depressive symptoms and higher moderate to vigorous physical activity (MVPA) scores compared to individual PA but there was no association between PA contexts and anxiety symptoms.
- A statistically significant mean difference was observed for social connectedness and MVPA across PA contexts with team sports having the highest scores followed by informal PA and lastly individual PA having the lowest scores.
- While the study found that PA context significantly affected scores for both social connectedness and PA volume it found that these variables did not mediate the relationship between PA context and the mental health outcomes studied and the authors do acknowledge that they did not prove their hypothesis.
- While the results are promising, the researchers only collected data at two points it would have been beneficial to have followed the cohort for a longer period collecting data over more time points to increase the reliability and validity of their results.
What conclusions can we take from this research?
- While the authors did not prove their hypothesis that social connectedness or PA volume mediates the positive mental health benefits from participating in team sports and informal group PA compared to individual PA it has backed up similar findings from previous studies that there are increased positive mental health benefits of participating in team sports and informal PA compared to individual PA.  Their findings in regards to depressive symptoms has also been reproduced in another study of young adults since this study was published. 
- Future studies should look to examine what other mechanisms may be involved in the benefits team sports and informal PA has on mental health and depressive symptoms.
- This study was completed in Canada which is a very similar country to Australia and makes the findings very relevant to the Australian population.
- While competing in team sports and informal PA may provide increased positive mental health benefits, participating in individual PA still provides a vast range of not just positive mental health benefits but also physical health benefits. The best advice is if you can find a team to play in or an informal PA setting that’s right for you go for it but if not just get out there and get exercising and you will still see benefits.
- If you're looking to join a sports team in Australia this website is a useful tool https://justplay.com.au
- If you're looking to participate in informal group PA some options include gym classes e.g. circuit classes and Yoga, boot camps or joining local exercise groups e.g. a running or swimming group.
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