Critical power: How different protocols and models affect its determination

In cycling, critical power (CP) and work above CP (W’) can be estimated through linear and nonlinearmodels. Despite the concept of CP representing the upper boundary of sustainable exercise, overestimations may be made as the models possess inherent limitations and the protocol design is not always appropriate. Objectives: to measure and compare CP and W’ through the exponential (CPexp), 3- parameter hyperbolic (CP3-hyp), 2-parameter hyperbolic (CP2-hyp), linear (CPlinear), and linear 1/time (CP1/time) models, using different combinations of TTE trials of different durations (approximately 1 to 20 min). Design: repeated measures. Methods: Thirteen healthy young cyclists (26±3yrs; 69.0±9.2kg; 174±10cm; 60.4±5.9mL·kg-1·min-1) performed five TTE trials on separate days. CP and W’ were modeled using two, three, four, and/or five trials. All models were compared against a criterion method (CP3-hyp with five trials; confirmed using the leaving-one-out cross-validation analysis) using smallest worthwhile change (SWC) and concordance correlation coefficient (CCC) analyses. Results: CP was considerably overestimated when only trials lasting less than 10 min were included, independent of the mathematical model used. Following CCC analysis, a number of alternative methods were able to predict our criterion method with almost a perfect agreement. However, the application of other common approaches resulted in an overestimation of CP and underestimation of W’, typically these methods only included TTE trials lasting less than 12 min. Conclusions: Estimations from CP3-hyp were found to be the most accurate, independently of TTE range. Models that include two trials between 12 and 20 min provide good agreement with the criterion method (for both CP and W’)

Determining the Maximal Physiological Steady State in Cycling with Precision: Critical Power Estimations or Self-selected Exercise Intensity?

Giving the inherent limitations of critical power (CP) testing and the demanding maximal lactate steady state (MLSS) protocol, this thesis aimed: i) to compare the power outputs (POs) derived from two methods of estimating CP (i.e., the power-time relationship (CPHYP) and the 3-minute all-out test (CP3MIN)) and the determined MLSS; and ii) to test cyclists’ ability to predict their highest sustainable PO (CPSELF). Thirteen healthy young participants (26±3 yr; 69.0±9.2 kg; 174±10 cm; 60.4±5.9 mL·kg-1·min-1) were tested. PO at MLSS was lower than CPHYP and CP3MIN (p0.05) to MLSS. The mean difference between the measures of MLSS and CPSELF was zero, and both methods presented similar (p>0.05) metabolic responses. The disagreement between CPHYP and CP3MIN with the PO at MLSS questions the ability of CP to estimate the maximal steady state, while CPSELF may offer an alternative approach to predict it with more precision

Sex differences in a chronometric mental rotation test with cube figures

In chronometric mental rotation tasks, sex differences are widely discussed. Most studies find men to be more skilled in mental rotation than women, which can be explained by the holistic strategy that they use to rotate stimuli. Women are believed to apply a piecemeal strategy. So far, there have been no studies investigating this phenomenon using eye-tacking methods in combination with electroencephalography (EEG) analysis: the present study compared behavioral responses, EEG activity, and eye movements of 15 men and 15 women while solving a three-dimensional chronometric mental rotation test. The behavioral analysis showed neither differences in reaction time nor in the accuracy rate between men and women. The EEG data showed a higher right activation on parietal electrodes for women and the eye-tracking results indicated a longer fixation in a higher number of areas of interest at 0 degrees for women. Men and women are likely to possess different perceptual (visual search) and decision-making mechanisms, but similar mental rotation processes. Furthermore, men presented a longer visual search processing, characterized by the greater saccade latency of 0 degrees-135 degrees. Generally, this study could be considered a pilot study to investigate sex differences in mental rotation tasks while combining eye-tracking and EEG methods

When is it appropriate to compare critical power to maximal lactate steady-state?

N/AThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author