The objective of this preliminary study was to determine the reproducibility of lower limbs skin temperature after cold stress test using the Game Ready system. Skin temperature of fourteen participants was measured before and after cold stress test using the Game Ready system and it was repeated the protocol in four times: at 9:00, at 11:00, at 19:00, and at 9:00 h of the posterior day. To assess skin temperature recovery after cold stress test, a logarithmic equation for each region was calculated, and constant (β₀) and slope (β₁) coefficients were obtained. Intraclass correlation coefficient (ICC), standard error (SE), and within-subject coefficient of variation (CV) were determined. No differences were observed between measurement times in any of the regions for the logarithmic coefficients (p > 0.38). Anterior thigh (β₀ ICC 0.33–0.47; β₁ ICC 0.31–0.43) and posterior knee (β₀ ICC 0.42–0.58; β₁ ICC 0.28–0.57) were the regions with the lower ICCs, and the other regions presented values with a fair and good reproducibility (ICC > 0.41). Posterior leg was the region with the better reproducibility (β₀ ICC 0.68–0.78; β₁ ICC 0.59–0.74; SE 3–4%; within-subject CV 7–12%). In conclusion, cold stress test using Game Ready system showed a fair and good reproducibility, especially when the posterior leg was the region assessed.

OBJETIVO. El objetivo principal de este estudio fue dilucidar los efectos de un ejercicio de fuerza de alta intensidad hasta el fallo en las respuestas conductuales y fisiológicas. El segundo objetivo fue evaluar el efecto del desempeño de las tareas cognitivas sobre los niveles de cortisol. MÉTODOS? Catorce sujetos activos completaron un ejercicio de estrés físico compuesto de 6 series de sentadillas hasta el fallo. El cortisol salival y las funciones cognitivas se evaluaron de forma contrabalanceada antes y después del ejercicio. RESULTADOS: Se mostraron niveles de cortisol más bajos antes del ejercicio y más altos antes de la tarea cognitiva (p<0.05). CONCLUSIONES: El estrés inducido por el ejercicio tuvo un efecto perjudicial en la atención. Además, los efectos del estrés en el rendimiento cognitivo parecen depender del tiempo transcurrido entre el cese del ejercicio y la evaluación de estos, pero no del tipo de ejercicio de alta intensidad realizado.

Cardiorespiratory fitness (CRF) is known to influence cognitive performance, particularly in tasks requiring sustained attention. However, the acute effects of high-intensity exercise on vigilance performance across different CRF levels remain underexplored. This study examined the impact of CRF level and a single bout of maximal incremental running on vigilance. Thirty-four male soldiers were assigned to either high- or low-CRF groups (n = 17 each). Participants performed a psychomotor vigilance go/no-go task at rest and immediately following exercise to exhaustion. Reaction time (RT), commission errors (CE), and omission errors (OE) were recorded and analyzed using repeated-measures ANOVA. Both groups showed improved RT after exercise compared to baseline. Participants with higher CRF consistently exhibited faster RTs across all task blocks. However, the low-CRF group demonstrated a greater magnitude of improvement post-exercise, suggesting a larger acute response to exercise. CRF modulates the cognitive effects of acute high-intensity exercise. Although all participants benefited, individuals with lower CRF showed relatively larger improvements in vigilance performance. These findings have implications for enhancing cognitive readiness in physically demanding settings, such as military operations.