Maintenance Notice

Due to necessary scheduled maintenance, the JMIR Publications website will be unavailable from Wednesday, July 01, 2020 at 8:00 PM to 10:00 PM EST. We apologize in advance for any inconvenience this may cause you.

Who will be affected?


Citing this Article

Right click to copy or hit: ctrl+c (cmd+c on mac)

Published on 27.07.16 in Vol 4, No 3 (2016): Jul-Sept

This paper is in the following e-collection/theme issue:

    Letter to the Editor

    The Era of Smartphones: Back to Our Biological Makeup?

    1European University Miguel de Cervantes, GIDFYS, Department of Health Sciences., Valladolid, Spain

    2Research Institute of Hospital 12 de Octubre (“i+12”), Madrid, Spain

    3Faculty of Health and Sport Sciences, University of Zaragoza, Huesca, Spain, Spain

    4European University, Madrid, Spain

    Corresponding Author:

    Alejandro Santos-Lozano

    European University Miguel de Cervantes

    GIDFYS, Department of Health Sciences.

    Padre Julio Chevalier, 2

    Valladolid, 47012


    Phone: 34 983001000 ext 1015

    Fax:34 983001000


    JMIR Mhealth Uhealth 2016;4(3):e63


    Physical inactivity is a major modifiable cardiovascular risk factor that has become a growing health problem in the 21st century: 83% of adolescents aged 13-15 years and approximately 1/3 of adults worldwide are inactive, that is, not meeting the minimum international physical activity (PA) recommendations (≥150 minutes/week of moderate to vigorous PA) [1,2]. Thus, the PA levels of the general population, especially of individuals at cardiovascular risk, should be routinely assessed by health care professionals, as it has been recently recommended by the American Heart Association [3]. To this end, accelerometers (usually attached to an elastic belt around the waist) allow objective quantification of PA by providing continuous recordings. At least 3 to 5 days of accelerometer monitoring (including weekend days) are required to determine habitual PA, and it is generally accepted that the device should be worn for ≥10 hours/day [4]. For this reason, the simple and inexpensive method of PA questionnaires is more widely used and generally better accepted. Unfortunately, the validity of self-reported PA is questionable.

    As recently discussed by Direito and collaborators [1], a reliable and simple strategy for assessing individual PA levels, without interfering with people’s daily life, is the use of smartphone apps. Smartphones are used by millions of people and many versions include a triaxial accelerometer and a positioning system among other types of sensors, thereby allowing the development of new apps with biomedical applicability. Other devices like the “Nike+ Move” app, which converts the smartphone into an “intelligent band,” or the Apple Watch and the HealthKit, might represent the beginning of the wearable’s revolution in health sciences, providing a great chance to monitor PA in an effective and inexpensive manner.

    We have evolved to perform high levels of PA (>2-3 hours) on a daily basis as persistent hunter-gatherers. However, technological improvements over few generations (industrial and, most recently, digital revolution) have led to dramatic reductions in our PA levels leading to chronic maladaptation and disease, with prolonged television viewing exemplifying a behavior that is at odds with our biological makeup and is associated with an increased risk of mortality [5]. Let us hope that the technological improvements that have made us become so inactive might pay off one day by helping increase our PA levels, that is, through the use of smartphones and wearable devices.

    Conflicts of Interest

    None declared.


    1. Direito A, Jiang Y, Whittaker R, Maddison R. Apps for IMproving FITness and Increasing Physical Activity Among Young People: The AIMFIT Pragmatic Randomized Controlled Trial. J Med Internet Res 2015;17(8):e210 [FREE Full text] [CrossRef] [Medline]
    2. Hallal PC, Andersen LB, Bull FC, Guthold R, Haskell W, Ekelund U, Lancet Physical Activity Series Working Group. Global physical activity levels: surveillance progress, pitfalls, and prospects. Lancet 2012 Jul 21;380(9838):247-257. [CrossRef] [Medline]
    3. Strath SJ, Kaminsky LA, Ainsworth BE, Ekelund U, Freedson PS, Gary RA, American Heart Association Physical Activity Committee of the Council on LifestyleCardiometabolic HealthCardiovascular‚ Exercise‚ Cardiac RehabilitationPrevention Committee of the Council on Clinical Cardiology‚Council. Guide to the assessment of physical activity: Clinical and research applications: a scientific statement from the American Heart Association. Circulation 2013 Nov 12;128(20):2259-2279 [FREE Full text] [CrossRef] [Medline]
    4. Pedišić Z, Bauman A. Accelerometer-based measures in physical activity surveillance: current practices and issues. Br J Sports Med 2015 Feb;49(4):219-223. [CrossRef] [Medline]
    5. Grøntved A, Hu FB. Television viewing and risk of type 2 diabetes, cardiovascular disease, and all-cause mortality: a meta-analysis. JAMA 2011 Jun 15;305(23):2448-2455 [FREE Full text] [CrossRef] [Medline]


    PA: physical activity

    Edited by P Morita; submitted 01.10.15; peer-reviewed by A Gonzalez de Agüero; accepted 28.10.15; published 27.07.16

    ©Alejandro Santos-Lozano, Nuria Garatachea, Helios Pareja-Galeano, Carmen Fiuza-Luces, Fabian Sanchis-Gomar, Alejandro Lucia. Originally published in JMIR Mhealth and Uhealth (, 27.07.2016.

    This is an open-access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in JMIR mhealth and uhealth, is properly cited. The complete bibliographic information, a link to the original publication on, as well as this copyright and license information must be included.