Validity of the iLOAD ® app for resistance training monitoring

• Published in: PeerJ (San Francisco, CA) Vol. 7; p. e7372
• Main Authors: de Sá, Evandro Claudino, Ricarte Medeiros, André, Santana Ferreira, André, García Ramos, Amador, Janicijevic, Danica, Boullosa, Daniel
• Format: Journal Article
• Language: English
• Published: United States PeerJ. Ltd 07.08.2019; PeerJ, Inc; PeerJ Inc
• Subjects: Anatomy and Physiology; Data Science; Exercise; Fitness equipment; Kinesiology; Knee; Laboratories; Physical fitness; Physical training; Public Health; Running; Smartphone application; Smartphones; Squat; Strength training; Total work; Validity; Velocity; Velocity-based training; Warm up (exercise); Weight training; Women; Brazil; Smartphone application; Velocity-based training; Squat; Total work
• ISSN: 2167-8359; 2167-8359
• DOI: 10.7717/peerj.7372

This study aimed (I) to assess the inter-rater agreement for measuring the mean velocity (MV) of the barbell with the ® app, and (II) to compare the magnitude of the MV and total work of a training session between the ® app and a linear encoder (reference method). Sixteen young healthy individuals (four women and 12 men) were tested in two sessions separated by 48 h. The 10 repetition maximum (RM) load was determined in the first testing session in the half squat exercise. The second testing session consisted of 3 sets of 10 repetitions during the half squat exercise performed against the 10RM load. Both the ® app and a linear encoder were used to calculate the MV and total work of each training set. MV was recorded with the ® app by two independent researchers to evaluate the inter-rater agreement. Trivial differences and nearly perfect correlations were observed between raters for the MV values collected under individual sets (effect size [ES] ≤ 0.02,  ≥ 0.987), as well as for the whole training session (  = 0.01,  = 0.997). Trivial-small differences and nearly perfect correlations were observed between the iLOAD® app and the linear encoder ( , Barcelona, Spain) for MV (  ≤ 0.25,  ≥ 0.903) and total work (  ≤ 0.05,  ≥ 0.973). Bland-Altman plots did not reveal heteroscedasticity of the errors between the ® app and the linear encoder for MV (  = 0.010) and total work (  < 0.001). ® is a valid smartphone app which can provide real-time feedback of the MV and total work completed in a set of multiple repetitions in the half squat exercise.