Threats to internal validity in exercise science : A review of overlooked confounding variables

Journal article

Halperin, Israel, Pyne, David B. and Martin, David T.. (2015). Threats to internal validity in exercise science : A review of overlooked confounding variables. International Journal of Sports Physiology and Performance. 10(7), pp. 823-829. https://doi.org/10.1123/IJSPP.2014-0566
AuthorsHalperin, Israel, Pyne, David B. and Martin, David T.
Abstract

Internal validity refers to the degree of control exerted over potential confounding variables to reduce alternative explanations for the effects of various treatments. In exercise and sports-science research and routine testing, internal validity is commonly achieved by controlling variables such as exercise and warm-up protocols, prior training, nutritional intake before testing, ambient temperature, time of testing, hours of sleep, age, and gender. However, a number of other potential confounding variables often do not receive adequate attention in sports physiology and performance research. These confounding variables include instructions on how to perform the test, volume and frequency of verbal encouragement, knowledge of exercise endpoint, number and gender of observers in the room, influence of music played before and during testing, and the effects of mental fatigue on performance. In this review the authors discuss these variables in relation to common testing environments in exercise and sports science and present some recommendations with the goal of reducing possible threats to internal validity.

Keywordsexperimental design; reliability; scientific process
Year2015
JournalInternational Journal of Sports Physiology and Performance
Journal citation10 (7), pp. 823-829
PublisherHuman Kinetics Publishers Inc.
ISSN1555-0265
Digital Object Identifier (DOI)https://doi.org/10.1123/IJSPP.2014-0566
PubMed ID25756869
Scopus EID2-s2.0-84943265790
Page range823-829
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All rights reserved
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Controlled
Output statusPublished
Publication dates
Online2015
Publication process dates
Deposited30 Jun 2025
Additional information

© 2015 Human Kinetics, Inc.

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