JOURNAL OF SPORTS SCIENCE & MEDICINE |
Research article |
RELIABILITY AND VALIDITY OF PHYSIOLOGICAL DATA OBTAINED WITHIN A CYCLE-RUN TRANSITION TEST IN AGE-GROUP TRIATHLETES | |||||||||
Veronica Vleck1, Gregoire P. Millet2, Francisco Bessone Alves1 and David J. Bentley3 | |||||||||
1CIPER, Faculty of Human Kinetics, Technical University of Lisbon, Estrada da Costa, Cruz Quebrada-Dafundo, Portugal; 2University of Lausanne, ISSUL Institute of Sport Sciences, Department of Physiology, Faculty of Biology and Medicine, Batiment Vidy, Lausanne, Switzerland; 3The School of Medical Science, the University of Adelaide, Adelaide, Australia | |||||||||
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© Journal of Sports Science and Medicine (2012) 11, 736 - 744 | |||||||||
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ABSTRACT | |||||||||||||
This study examined the validity and reliability of a sequential "Run-Bike-Run" test (RBR) in age-group triathletes. Eight Olympic distance (OD) specialists (age 30.0 ± 2.0 years, mass 75.6 ± 1.6 kg, run VO2max 63.8 ± 1.9 ml·kg-1·min-1, cycle VO2peak 56.7 ± 5.1 ml·kg-1·min-1) performed four trials over 10 days. Trial 1 (TRVO2max) was an incremental treadmill running test. Trials 2 and 3 (RBR1 and RBR2) involved: 1) a 7-min run at 15 km·h-1 (R1) plus a 1-min transition to 2) cycling to fatigue (2 W·kg-1 body mass then 30 W each 3 min); 3) 10-min cycling at 3 W·kg-1 (Bsubmax); another 1-min transition and 4) a second 7-min run at 15 km·h-1 (R2). Trial 4 (TT) was a 30-min cycle - 20-min run time trial. No significant differences in absolute oxygen uptake (VO2), heart rate (HR), or blood lactate concentration ([BLA]) were evidenced between RBR1 and RBR2. For all measured physiological variables, the limits of agreement were similar, and the mean differences were physiologically unimportant, between trials. Low levels of test-retest error (i.e. ICC <0.8, CV<10%) were observed for most (logged) measurements. However [BLA] post R1 (ICC 0.87, CV 25.1%), [BLA] post Bsubmax (ICC 0.99, CV 16.31) and [BLA] post R2 (ICC 0.51, CV 22.9%) were least reliable. These error ranges may help coaches detect real changes in training status over time. Moreover, RBR test variables can be used to predict discipline specific and overall TT performance. Cycle VO2peak, cycle peak power output, and the change between R1 and R2 (deltaR1R2) in [BLA] were most highly related to overall TT distance (r = 0.89, p < 0. 01; r = 0.94, p < 0.02; r = 0.86, p < 0.05, respectively). The percentage of TR VO2max at 15 km·h-1, and deltaR1R2 HR, were also related to run TT distance (r = -0.83 and 0.86, both p < 0.05). Key words: Multi-discipline, reproducibility, time-trial, test, adaptation. |
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INTRODUCTION | |||||||||||||
Coaches require a reasonable degree of confidence that the changes in test measures that are obtained by their athlete(s) are due to training adaptations rather than due to measurement error (Atkinson and Nevill, 1998). The scores that are obtained on a laboratory test must also adequately reflect the needs of the sport. Therefore, the physiological measures that are obtained within any "sport specific test" should be shown to be reliable, and to be relevant to performance in that sport. |
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METHODS | |||||||||||||
The experiment involved four trials over 10-days, each separated by at least 48 h. The testing comprised: (1) an incremental treadmill running test to exhaustion (TRVO2max); (2) and (3) the "Run-Bike-Run" trial (termed RBR1 on its first occasion and, when repeated, RBR2); and 4) a laboratory based 30-minute cycle-20-min run distance trial (TT). TRVO2max was completed first and the remaining tests were performed in randomised counterbalanced order. Subjects During Bsubmax, cycle economy (B_EC) was measured as the ratio of the power output (W) to VO2 (l·min-1) consumed (Millet et al., 2004). In the last 60 s of R1 and R2, VO2 (ml·kg-1·min-1) was averaged and economy (ECRun) calculated (VO2 / km·h-1) (Di Prampero, 1986). Cycle-run time trial (TT) Statistical analyses |
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RESULTS | |||||||||||||
The subjects' mean personal best OD times were 2:09:28 ± 0:04:51 hh:mm:ss (involving 40 km cycle times of 1:09:10 ± 0:04:13 hh:mm:ss and 10 km run times of 0:41:22 ± 0:02:53 hh:mm:ss). Their mean age, mass, and peak running speeds (Vmax) were 30.0 ± 2.0 years, 75.6 ± 1.6 kg, and 19.7 ± 0.3 km·h-1. Their run ventilatory threshold (TRVT) of 3.5 ± 0.1 l·min-1, occurred at 74.2 ± 3.4% TRVO2max. Details of their physiological responses to RBR1 and RBR2 are presented in Table 1. The athletes obtained significantly lower absolute cycle peak VO2 values than TRVO2max values (4.8 ± 0.2 vs. 4.2 ± 0.4 l·min-1, p < 0.05). |
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DISCUSSION | |||||||||||||
Both the subject characteristics and their physiological responses (Tables 1 and 2), confirmed them as well-trained age-group but not elite triathletes. In common with the athletes of Millet et al., 2003, Millet and Bentley, 2004, and Schabort et al., 2000, the subjects displayed significantly greater VO2max values for running than for cycling (p < 0.05). As the VO2 values of the athletes were reproducible this is unlikely to have been due to fatigue from R1 in Bmax. However, the athletes in this study were older and possessed lower TR VO2max, B VO2peak, and Wpeak (W), than the Senior male Elites of previous work (Millet et al., 2003; Millet and Bentley, 2004; Schabort et al., 2000). The mean Wpeak attained by the triathletes during Bmax was 332 ± 9 W, as compared to 385 ± 50 W in Millet et al., 2003 and to 385 ± 14 W in Schabort et al., 2000, respectively. |
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AUTHORS BIOGRAPHY | |
Veronica VLECK Employment: Chair of the Medical and Research Committee of the European Triathlon Union and a full-time FCT Research Fellow at the Technical University of Lisbon, POR. Degree: PhD Research interests: Mechanisms of fatigue, the extent and risk factors for injury and illness, prediction of maladaptation in multi- as opposed to single discipline- E-mail: vvleck@fmh.utl.pt | |
Gregoire MILLET Employment: Prof. of exercise physiology at the Univ. of Lausanne, the Olympic capital, and Director of the Institute of Sport Sciences (ISSUL). Degree: PhD Research interests: Innovative E-mail: gregoire.millet@unil.ch | |
Francisco ALVES Employment: Full prof. of the Faculty of Human Kinetics, director of the Lab. of Exercise Physiology. Degree: PhD Research interests: Bioenergetic and biomechanical efficiency in endurance sports performance, with special interest in swimming and E-mail: falves@fmh.utl.pt | |
David BENTLEY Employment: Academic staff member and exercise physiologist at the School of Medical Science, Adelaide University. Degree: PhD Research interests: Applied and clinical exercise and sport science. E-mail: david.bentley@adelaide.edu.au | |