Enhancing specificity in proxy-design for the assessment of bioenergetics

Faculty of Applied Health Sciences, Brock University, St Catharines, Canada.
Journal of Science and Medicine in Sport (Impact Factor: 3.19). 07/2004; 7(2):197-204. DOI: 10.1016/S1440-2440(04)80009-4
Source: PubMed


The purpose of this study was to examine the hypothesis that improved prediction of bioenergetics may be achieved when proxies are designed to simulate closely gold standard laboratory protocols. To accomplish this, a modified 'square' variation (SST) of the classical 20m Multistage Shuttle Run Test (MST) was designed aiming to reduce the stopping, turning and side-stepping manoeuvres. Within two weeks, 50 male volunteers (age 21.5+/-1.6, BMI 24.4+/-2.2) randomly underwent three maximal oxygen uptake (VO2max) assessments using a treadmill test (TT), the SST and MST. To assess SST reproducibility, 10 randomly-selected subjects performed the test twice. Validity results showed that mean predicted VO2max from SST was not significantly different compared to TT VO2max (p>0.05). In contrast, the equivalent value from MST was significantly higher (p<0.001) than TT. Furthermore, TT VO2max correlated with SST and MST at r=0.88 (p<0.001) and r=0.61 (p<0.05), respectively. The '95% limits of agreement' analysis (LIM(AG)) for SST and MST indicated a range of error equal to -0.5+/-5.4 and 8.1+/-8.0 ( with a coefficient of variation of +/-6 and +/-8.2%, respectively. Test-retest results for SST revealed no mean difference in VO2max (p>0.05) and a correlation coefficient of r=0.98 (p<0.001), while LIM(AG) demonstrated a range of error equal to -0.2+/-2.6 ( with a coefficient of variation of +/-5.6%. It is concluded that, compared to MST, the SST had a higher agreement with TT. The latter may well be explained by the closer simulation in bioenergetics between the two protocols (ie, the continuous nature of SST provides a closer proxy of TT).

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    • "Despite the fact that the time of motor activity is relatively long in its training sessions (classes), curiously the SD competitive presentations are performed with intense physical pace and last only three to seven minutes. This usual practice could be considered as a physiological failure, because it probably infringes the specificity of training principle (Flouris et al., 2004). Actually, other dance styles, like classic and contemporary ballet (Schantz and Astrand, 1984; Redding et al., 2009) have been studied in relation to the effect of physical training workouts isolated (not the classes about techniques), but little is known about the best ways to improve sport-specific performance in SD.Although, nowadays SD has been used as a form of physical exercise, including its practice in dance studios, for artistic expression, and in competitions, there are some studies about its social effects (Saito et al., 2006; Swami and Tovee, 2009) but there is no study regarding its physiological demands. "

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    ABSTRACT: Human bioenergetics has been extensively assessed by means of field proxies (ie, cardiorespiratory fitness field tests) during the last two decades. A systematic review of the germane literature, however, suggests considerable controversy as to whether the present tests lead to valid measurements of energy expenditure/utilisation. The present paper suggests that current modalities of field testing being used as predictive models for bioenergetics may suffer from methodological limitations, stemming primarily from inappropriate design. A major weakness in the theoretical basis of proxies is that, although based on field measurements, it seeks to predict laboratory bioenergetics which, in turn, are used to provide information on field performance. Hence, it seems reasonable that the number of transformations increases the potential for error and may have significant impact on the prediction of bioenergetics. Recent studies asserted the importance of achieving 'energy equilibrium' between the reference standard and each proxy. The suggested approach involves designing proxies that closely simulate each laboratory protocol used as reference standard. The theoretical bases of previous and contemporary approaches are discussed in an attempt to increase the validity of current proxy assessments.
    Full-text · Article · Jul 2005 · Journal of Science and Medicine in Sport
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