Reliability/Validity of the Fortius Trainer

Abstract

This study examined the reliability/validity of power output measured using the Fortius Virtual Reality cycle trainer. 10 cyclists (age: 28±6 years; V˙O₂max: 60.9±7.2 ml · kg⁻¹ · min⁻¹; peak power: 393±82 W) completed three 20 km time trials on a Fortius cycle trainer. During each time trial, power output was measured at 1 Hz using the Fortius internal software and a PowerTap power monitor. Validity calculated for the Fortius trainer; Pearson correlation coefficient (r=0.99; 95% CI: 0.98–0.99; p<0.01) and typical error of estimate (3.5%; 95% CI: 3.2–3.9%), was similar to other established laboratory ergometers. No differences (F_2,16=0.32; p=0.73) in mean 20 km power were observed between trial 1 (253±46 W), 2 (258±49 W), or 3 (255±50 W). Test-retest reliability (intraclass correlation coefficient (ICC) and coefficient of variation (CV)) was better between trial 2 and 3 (ICC=1.00 (CI: 0.98–1.00); CV: 1.6% (CI: 1.1–3.3%)) compared with trial 1 and 2 (ICC=0.98 (CI: 0.91–1.00); CV: 3.3% (CI: 2.2–6.4%)). The Fortius cycle trainer is a valid and reliable device for the measurement of power output in cyclists, thus providing an alternative to larger more expensive laboratory ergometers.

performance - ergometer - testing - measurement

References

• 1 Abbiss CR, Levin G, McGuigan MR, Laursen PB. Reliability of power output during dynamic cycling.  Int J Sports Med. 2008;  29 574-578
• 2 Abbiss CR, Quod MJ, Levin G, Martin DT, Laursen PB. Accuracy of the Velotron ergometer and SRM power meter.  Int J Sports Med. 2009;  30 107-112
• 3 Atkinson G, Nevill AM. Selected issues in the design and analysis of sport performance research.  J Sports Sci. 2001;  19 811-827
• 4 Bertucci W, Duc S, Villerius V, Pernin JN, Grappe F. Validity and reliability of the PowerTap mobile cycling powermeter when compared with the SRM Device.  Int J Sports Med. 2005;  26 868-873
• 5 Esposito F, Mathieu-Costello O, Shabetai R, Wagner PD, Richardson RS. Limited maximal exercise capacity in patients with chronic heart failure: partitioning the contributors.  J Am Coll Cardiol. 2010;  55 1945-1954
• 6 Guiraud T, Leger L, Long A, Thebault N, Tremblay J, Passelergue P. Vo2 requirement at different displayed power outputs on five cycle ergometer models: a preliminary study.  Br J Sports Med. 2010;  44 449-454
• 7 Harriss DJ, Atkinson G. International Journal of Sports Medicine – Ethical Standards in Sport and Exercise Science Research.  Int J Sports Med. 2009;  30 701-702
• 8 Hawley JA, Noakes TD. Peak power output predicts maximal oxygen uptake and performance time in trained cyclists.  Eur J Appl Physiol. 1992;  65 79-83
• 9 Hopkins WG. Analysis of reliability with a spreedsheet (beta version). In: A New View of Statistics: Internet Society of Sports Science 2009
• 10 Hopkins WG. Analysis of validity by linear regression (Excel Spreedsheet). In: A New View of Statistics: Internet Society for Sports Science 2000
• 11 Hopkins WG. Measures of reliability in sports medicine and science.  Sports Med. 2000;  30 1-15
• 12 Hopkins WG, Hawley JA, Burke LM. Design and analysis of research on sport performance enhancement.  Med Sci Sports Exerc. 1999;  31 472-485
• 13 Hopkins WG, Schabort EJ, Hawley JA. Reliability of power in physical performance tests.  Sports Med. 2001;  31 211-234
• 14 Jeukendrup AE, Craig NP, Hawley JA. The bioenergetics of World Class Cycling.  J Sci Med Sport. 2000;  3 414-433
• 15 Kirkland A, Coleman D, Wiles JD, Hopker J. Validity and reliability of the Ergomopro powermeter.  Int J Sports Med. 2008;  29 913-916
• 16 Lamberts RP, Rietjens GJ, Tijdink HH, Noakes TD, Lambert MI. Measuring submaximal performance parameters to monitor fatigue and predict cycling performance: a case study of a world-class cyclo-cross cyclist.  Eur J Appl Physiol. 2010;  108 183-190
• 17 Laviolette L, O’Donnell DE, Webb KA, Hamilton AL, Kesten S, Maltais F. Performance during constant workrate cycling exercise in women with COPD and hyperinflation.  COPD. 2009;  6 340-351
• 18 Paton CD, Hopkins WG. Tests of cycling performance.  Sports Med. 2001;  31 489-496
• 19 Smith MF, Davison RC, Balmer J, Bird SR. Reliability of mean power recorded during indoor and outdoor self-paced 40 km cycling time-trials.  Int J Sports Med. 2001;  22 270-274
• 20 Sporer BC, McKenzie DC. Reproducibility of a laboratory based 20-km time trial evaluation in competitive cyclists using the Velotron Pro ergometer.  Int J Sports Med. 2007;  28 940-944
• 21 Zavorsky GS, Murias JM, Gow J, Kim DJ, Poulin-Harnois C, Kubow S, Lands LC. Laboratory 20-km cycle time trial reproducibility.  Int J Sports Med. 2007;  28 743-748

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