Sports Medicine

, Volume 49, Issue 1, pp 159–161 | Cite as

Comment on: “Cardiorespiratory Fitness in Childhood and Adolescence Affects Future Cardiovascular Risk Factors: A Systematic Review of Longitudinal Studies”

  • Jakob TarpEmail author
  • Knut Eirik Dalene
  • Jostein Steene-Johannessen
  • Ulf Ekelund
Letter to the Editor

Dear Editor,

We would like to congratulate Mintjens et al. on their systematic review ‘Cardiorespiratory Fitness in Childhood and Adolescence Affects Future Cardiovascular Risk Factors: A Systematic Review of Longitudinal Studies’, published recently in Sports Medicine [1]. The article provided valuable recommendations for future work, including recommendations to reduce heterogeneity between studies, and an insightful reflection on the intricate relationship between physical activity, cardiorespiratory fitness and adiposity. However, we wish to highlight certain nuances that we feel are of importance when interpreting the results of this review, as well as observational cohort studies in general.

The utility of quality-scores/checklists for evaluating potential threats (biases) to scientific conclusions from systematic reviews is debatable [2]. Mintjens et al. [1] included two different systems for rating articles in their review. The STROBE quality assessment was used to rate...


Compliance with ethical standards


No sources of funding were used to assist in the preparation of this letter.

Conflict of interest

Jakob Tarp, Knut Eirik Dalene, Jostein Steene-Johannessen and Ulf Ekelund declare that they have no conflicts of interest relevant to the content of this letter.


  1. 1.
    Mintjens S, Menting MD, Daams JG, van Poppel MNM, Roseboom TJ, Gemke RJBJ. Cardiorespiratory fitness in childhood and adolescence affects future cardiovascular risk factors: a systematic review of longitudinal studies. Sports Med. 2018;48(11):2577–605. Scholar
  2. 2.
    Mueller M, D’Addario M, Egger M, Cevallos M, Dekkers O, Mugglin C, et al. Methods to systematically review and meta-analyse observational studies: a systematic scoping review of recommendations. BMC Med Res Methodol. 2018;18(1):44.CrossRefGoogle Scholar
  3. 3.
    Castro-Pinero J, Artero EG, Espana-Romero V, Ortega FB, Sjostrom M, Suni J, et al. Criterion-related validity of field-based fitness tests in youth: a systematic review. Br J Sports Med. 2010;44(13):934–43.CrossRefGoogle Scholar
  4. 4.
    Batista MB, Romanzini CLP, Castro-Pinero J, Ronque ERV. Validity of field tests to estimate cardiorespiratory fitness in children and adolescents: a systematic review. Rev Paul Pediatr. 2017;35(2):222–33.CrossRefGoogle Scholar
  5. 5.
    Artero EG, Espana-Romero V, Castro-Pinero J, Ortega FB, Suni J, Castillo-Garzon MJ, et al. Reliability of field-based fitness tests in youth. Int J Sports Med. 2011;32(3):159–69.CrossRefGoogle Scholar
  6. 6.
    Savonen K, Krachler B, Hassinen M, Komulainen P, Kiviniemi V, Lakka TA, et al. The current standard measure of cardiorespiratory fitness introduces confounding by body mass: the DR’s EXTRA study. Int J Obes (Lond). 2012;36(8):1135–40.CrossRefGoogle Scholar
  7. 7.
    Hill AB. The environment and disease: association or causation? J R Soc Med. 1965;58:295–300.Google Scholar
  8. 8.
    Grontved A, Ried-Larsen M, Ekelund U, Froberg K, Brage S, Andersen LB. Independent and combined association of muscle strength and cardiorespiratory fitness in youth with insulin resistance and beta-cell function in young adulthood: the European Youth Heart Study. Diabetes Care. 2013;36(9):2575–81.CrossRefGoogle Scholar
  9. 9.
    Crump C, Sundquist J, Winkleby MA, Sieh W, Sundquist K. Physical fitness among Swedish military conscripts and long-term risk for type 2 diabetes mellitus: a cohort study. Ann Intern Med. 2016;164(9):577–84.CrossRefGoogle Scholar
  10. 10.
    Crump C, Sundquist J, Winkleby MA, Sundquist K. Interactive effects of obesity and physical fitness on risk of ischemic heart disease. Int J Obes (Lond). 2017;41(2):255–61.CrossRefGoogle Scholar
  11. 11.
    Crump C, Sundquist J, Winkleby MA, Sundquist K. Interactive effects of physical fitness and body mass index on risk of stroke: a national cohort study. Int J Stroke. 2016;11(6):683–94.CrossRefGoogle Scholar
  12. 12.
    Aadland E, Andersen LB, Lerum O, Resaland GK. The Andersen aerobic fitness test: new peak oxygen consumption prediction equations in 10 and 16-year olds. Scand J Med Sci Sports. 2018;28(3):862–72.CrossRefGoogle Scholar
  13. 13.
    Hutcheon JA, Chiolero A, Hanley JA. Random measurement error and regression dilution bias. BMJ. 2010;23(340):c2289.CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2018

Authors and Affiliations

  1. 1.Department of Sports MedicineNorwegian School of Sport SciencesOsloNorway

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