Author(s): KETELHUT, S., HUG, D., BENZING, V., EKLEMOVIC, G., FENZL, T., BRAND, R., Institution: UNIVERSITY OF BERN, Country: SWITZERLAND, Abstract-ID: 2541

INTRODUCTION:
Cardiopulmonary exercise testing (CPET) is considered the gold standard for assessing cardiorespiratory fitness. A critical requirement for a valid CPET is that participants achieve true maximal exertion. When individuals terminate the test prematurely, the accuracy of the outcomes is compromised, leading to underestimation of cardiorespiratory fitness, diagnostic errors, and inappropriate exercise or treatment prescriptions. Although verbal encouragement is commonly used to promote maximal effort, its effectiveness is questionable, and its delivery lacks standardization. Complex auditory stimuli may provide a more standardized and engaging approach to encouragement. Therefore, this study compared the effects of verbal encouragement and complex auditory stimuli on physiological and psychological outcomes during CPET.
METHODS:
In a randomized, within-subject crossover trial, 29 individuals (27.9 ± 4.3 years; 11 females) who were not regularly engaged in structured physical exercise and had no prior experience with CPET completed three CPETs (ramp protocol: 15 W·min⁻¹) under different encouragement conditions: no encouragement (CC), standardized verbal encouragement (VC), and complex, non-musical auditory stimuli (AC). Outcomes included peak oxygen uptake (VO₂peak), maximal power output (Wmax), time to exhaustion, ratings of perceived exertion, affective valence, enjoyment, and attentional focus.
RESULTS:
A significant effect of condition was found for VO₂peak (p < .001, η²ₚ = .35), with higher values in AC compared to VC (p = .001, η²ₚ = .32) and CC (p < .001, η²ₚ = .44), while VC and CC did not differ. Wmax also differed significantly between conditions (p < .001, η²ₚ = .26), with higher values in AC compared to VC (p < .001, η²ₚ = .38) and CC (p = .006, η²ₚ = .27), and no difference between VC and CC. Time to exhaustion showed a significant main effect (p = .021, η²ₚ = .13), although post-hoc comparisons were not significant. No significant effects were observed for rating of perceived exertion (p = .123, η²ₚ = .08), affective valence (p = .080, η²ₚ = .09), or exercise enjoyment (p = .084, η²ₚ = .09). In contrast, attentional focus demonstrated a large effect of condition (p < .001, η²ₚ = .54), with AC eliciting greater dissociative focus than VC (p = .034, η²ₚ = .11) and CC (p < .001, η²ₚ = .63), and VC higher than CC (p = .001, η²ₚ = .34).
CONCLUSION:
This is the first study to demonstrate that complex, non-musical auditory stimuli enhance performance and promote a stronger dissociative attentional focus during CPET compared with traditional verbal encouragement, without increasing perceived exertion or negatively affecting affective responses. Thus, complex auditory stimuli may represent a more effective and standardized approach to encouragement than traditional verbal encouragement, potentially improving the validity and reliability of CPET.