ECSS Paris 2023: CP-AP16
INTRODUCTION: A persistent issue in critical power (CP) and W´ research is the variability in methodologies across studies. Some research groups employ the traditional approach, which involves multiple exhaustive trials of differing durations to determine CP and W´. Others question the validity of this method and advocate the 3-min all-out test (3AOT) as a potentially more accurate alternative. The traditional approach relies on the relationship of power vs. duration and mathematical modelling to determine CP and W´. In contrast, the 3AOT is designed to deplete W´ within the first 2.5 minutes, thereby establishing a plateau that represents CP within the last 30 s of the test. At present, there is equivocal evidence regarding whether these two approaches can be used interchangeably. Therefore, the aim of this meta-analysis was to examine potential differences between the traditional method and the 3AOT. METHODS: A systematic search of the PubMed database using the terms “all-out AND ‘critical power’” identified 147 studies. Inclusion criteria were: (1) participants were healthy, over 18 years of age, and included both trained and untrained individuals; (2) studies employed the traditional determination of CP and W´ using time-to-exhaustion (TTE) or time-trial (TT) protocols and a 3AOT approach (isokinetic, linear, or relative to body mass); and (3) CP was reported in watts (W) and W´ in joules (J). Studies were excluded if they involved interventions such as supplementations, hypoxia/hyperoxia, or heat exposure. Statistical analyses were conducted using Review Manager (RevMan 5.4.2.). Results are presented as standardised mean differences (SMD) with 95% confidence intervals (CI). SMDs were considered statistically significant if the 95% CI did not include 0 (P < 0.05). Heterogeneity was assessed using the I-squared statistic, and effect sizes were interpreted analogously to Cohen’s d. RESULTS: The analysis included 16 study results, encompassing a total of 169 participants, for both CP and W´ outcomes. Fixed-effect model pooled analysis indicated that the traditional method produced significantly lower CP values compared to the 3AOT (SMD -0.26; 95% CI: -0.47 to -0.04; P = 0.02), with no observed heterogeneity (I-squared = 0%) and a small effect size. Conversely, random-effects model pooled analysis revealed significantly higher W´ values for the traditional approach (SMD 0.74; 95% CI: 0.38 to 1.10; P < 0.01), with moderate heterogeneity observed (I-squared = 59%) and a moderate effect size. CONCLUSION: The traditional approach yields significantly lower CP values and significantly higher W´ values compared to the 3AOT, indicating that these methods cannot be used interchangeably in science and praxis. However, these findings do not resolve the critical question of which approach most accurately reflects the maximal metabolic steady state, and therefore, which best defines the boundary between the heavy and severe exercise intensity domains.
Read CV Christoph TriskaECSS Paris 2023: CP-AP16
INTRODUCTION: Aerobic fitness in athletes is mainly determined by their aerobic and anaerobic thresholds. One of the most used methods for determining Aerobic fitness requires the measurement of physiological parameters, such as ventilation or blood lactate during maximum exercise, which can become a limitation in the application for all populations. A protocol with non-exhaustive double efforts (NEDE) could be a low-cost and short-duration option for all populations. The study aimed to verify the associations of NEDE with the ventilatory thresholds and investigate the reliability of NEDE for cycling. METHODS: Nine healthy male amateur cyclists (age: 44 ± 9 yrs, height: 178.4 ± 8.3 cm, weight: 75.6 ± 9.1 kg, VO2max: 47.25 ± 5.05 ml.kg-1.min-1) performed a protocol divided into 3 stages: (1) a incremental test for ventilatory threshold 1 (VT1) and ventilatory threshold 2 (VT2) determinations from ventilatory parameters; (2) the NEDE (NEDE 1) test measured by blood lactate concentration and (3) a retest of NEDE (NEDE 2) for reliability analysis. The NEDE test consisted of 4 sessions at different cycling intensities. Each session featured a double-effort design, consisting of two 180-second cycling at identical velocity (E1 and E2), interspersed with a 90-second passive recovery interval. The delta lactate (LAC) values recorded following both E1 and E2 efforts (delta = E2 - E1) across all four sessions were used to estimate, via linear regression, the exercise intensity corresponding to a "null delta”, which theoretically represents the intensity equivalent to maximal aerobic capacity. ANOVA variance analysis for repeated measures and Pearson test were applied, respectively, to compare and to correlate NEDE 1, NEDE 2, VT1, and VT2. Intraclass correlation verified reliability between NEDE 1 and NEDE 2. In addition, the coefficient of variation and standard error were calculated. RESULTS: NEDE 1 (159.9 ± 32.8 W) and 2 (162.5 ± 39.9 W) presented no differences with the VT1 (136.1± 37.8 W, p =0.142 and 0.086, respectively). Significant correlations (r = 0.724 and 0.773; p = 0.027 and 0.015, respectively), moderate coefficient of variance (11.4 % and 2.9 %) and moderate typical error (18.8 W and 18.7 W) were observed between NEDE 1 and 2 with VT1, respectively. In addition, NEDE 1 and 2 showed a significant correlation (r = 0.847 and 0.846; p = 0.004 and 0.004, respectively) with VT2 (233.3 ± 30.6 W). The intraclass correlation coefficient indicated significant reliability for NEDE 1 versus NEDE 2 (0.961, p<0.000) with a small coefficient of variance and typical error (2.9% and 7.3W). CONCLUSION: The non-exhaustive double effort test for cycling is valid for estimating the first ventilatory threshold and demonstrates high reliability, which could be a low-cost and short-duration protocol option for all populations.
Read CV Bahareh VeghariaslECSS Paris 2023: CP-AP16