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Critique of ‘The physical activity myth’ paper: discussion of flawed logic and inappropriate use of evidence
  1. Paul Kelly1,
  2. Graham Baker1,
  3. Chloe McAdam1,
  4. Karen Milton2,
  5. Justin Richards3,
  6. Charlie Foster2,
  7. Marie Murphy4,
  8. Nanette Mutrie1
  1. 1Physical Activity for Health Research Centre (PAHRC), Institute for Sport, Physical Education and Health Sciences, University of Edinburgh, Edinburgh, UK
  2. 2Nuffield Department of Population Health, University of Oxford, Oxford, UK
  3. 3School of Public Health, University of Sydney, Sydney, Australia
  4. 4School of Health Science, University of Ulster, Newtownabbey, UK
  1. Correspondence to Dr Paul Kelly, Physical Activity for Health Research Centre (PAHRC), Institute for Sport, Physical Education and Health Sciences, University of Edinburgh, Edinburgh EH8 8AQ, UK; p.kelly{at}

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We read the recent Editorial “It is time to bust the myth of physical inactivity and obesity: you cannot outrun a bad diet”1 with interest. While discussion about prevention and treatment of obesity is vital, we feel this piece did not make a positive contribution to ongoing scientific debate.

We understand that the Editorial was written to be provocative, but are concerned about the potential damage of misleading and extreme opinions on issues of public health. We believe that there are serious flaws in the interpretation, understanding and reasoning that should not go unchecked.

We highlight four points to demonstrate these flaws, rebut the assertions of the authors, and show why the debate on physical activity (PA) and obesity should disregard the Editorial.

Major flaws in “The Physical Activity Myth” paper

1. Title: “The myth of physical inactivity and obesity”

What myth are the authors referring to? This should be outlined, explaining whether this is authors’ opinion, or can be evidenced in some way. Further, much of the content is unrelated to this title. It is imperative that a title reflects the content of a piece of scientific work whether it is opinion …

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  • Twitter Follow Paul Kelly at @narrowboat_paul, Justin Richards at @JRLovesCycling and Nanette Mutrie at @nanettemutrie

  • Authors' note This Editorial is based on “An open letter: 12 reasons why “The physical activity myth” paper should not have been published” that can be read in full here

  • Contributors PK, CM, GB and NM conceived the letter. MM, CF, KM and JR provided critical feedback. All authors helped write the final version.

  • Competing interests We declare that we have an interest in physical activity research, public health and the maintenance of the highest academic standards. We receive funding from a number of national and international research councils, and companies that manufacture physical activity measurement devices.

  • Provenance and peer review Not commissioned; externally peer reviewed.