Can the inner eye canthus temperature be used as an alternative method to measure core temperature in sleep-deprived individuals?

Core temperature is used in several situations, including studies on biological rhythms and circadian markers of physical performance. Measuring the inner eye canthus (Tco) temperature is a method proposed to identify core temperature, but it has shown little concordance in physical exercise situations and has not yet been used in studies with measurements taken throughout the day. The objective of this study was to compare the measurements and daily behavior of Tco obtained by infrared thermography with rectal temperature (Tre) during a prolonged waking protocol. Eleven male individuals participated in the study, who remained in the laboratory for at least 38 h using an actigraph to determine the wakefulness time and were monitored during the entire period. The Tre and Tco measurements were performed every 3 h. The ANOVA was used for repeated measurements followed by Bonferroni's post-hoc test to find the limits of concordance/proximity, while the Bland and Altman method and the Intraclass Correlation Coefficient were used to establish the reliability between the pairs. The significance level adopted was p < 0.05. The results demonstrate significant differences, low levels of concordance and unsatisfactory reliability levels between Tco and Tre at all 13 analyzed moments, in addition to not showing measurement reliability when all data are used together with the 143 temperature measurements. Daily behavior analysis shows moments with similar behavior with an increase in Tco and Tre, but at other times the behavior was the opposite, with a decrease in one measurement and an increase in the other. Based on the results presented, it is not recommended to use the inner eye canthus temperature as a substitute for rectal temperature for measuring core temperature at different times of the day or in sleep-deprived individuals.

Sleep regularity in athletes: Comparing sex, competitive level and sport type.

This study aims to describe the athletes' sleep regularity using the Sleep Regularity Index (SRI) and determine whether factors, such as sex, competitive level and sport type, could affect the sleep/wake rhythm. It is a descriptive, cross-sectional study consisting of 172 athletes (25 ± 7 y old; 45 women). Seventy-three competed in team sports and 99 in individual sports. Furthermore, 56 competed in the international level, 95 in the national and 21 in the regional. We recorded the SRI values for at least 5 d via continuous actigraphy. We recorded a mean SRI value of 73 ± 12. We found no significant differences between athletes' sleep parameters in relation to sleep regularity. Furthermore, SRI data showed no correlations (Spearman's ρ) with sleep parameters, bed time and wake time. Female athletes (p = 0.001) and individual sport athletes (p = 0.001) reported better sleep regularity than their counterparts. International-level athletes reported better sleep regularity than those in other competitive levels (national: p = 0.001; regional: p = 0.024). Our study showed that international level athletes, female athletes and individual sport athletes reported better sleep regularity. Additionally, SRI data showed no correlation with athletes' sleep parameters, bed and wake time.

The effects of COVID-19 quarantine on eating and sleeping behaviors.

Abstract: Since the beginning of the pandemic, the population has been exposed to a substantial period of social isolation, which leads to anxiety, fear, and metabolic and immune impairments. Purpose: Considering that sleep restriction influences eating behavior, we highlight that changes in it may occur during the COVID-19 quarantine. Alterations in feeding time can uncouple the body clocks, leading to circadian misalignment and consequently to a disruption in homeostasis and disturbances in many metabolic functions. Method: Narrative review. Results: Do not apply. Conclusion: The increase of body weight is related to increased food intake in response to mental stress and more time spent at home, increased opportunity to feed, and increased visual and olfactory stimulation to eat, which represents a potential risk of overfeeding nowadays. In this article, we postulate that the unusual lifestyle imposed by the COVID-19 quarantine may induce a circadian misalignment, which is capable to induce alterations on eating and sleep behaviors.

Qual a contribuição das características antropométricas na velocidade de corrida de curta distância? / What is the contribution of anthropometric characteristics on sprint run? / Qué es la contribución la características antropométricas en la carrera de velocidad

O estudo buscou avaliar os efeitos das características antropométricas na velocidade de corrida. Foram avaliados a estatura, massa corporal (MC), índice de massa corporal (IMC), dobra cutânea panturrilha (DCpa), comprimento da tíbia (Ctíbia) e velocidade da corrida (50m) de 235 estudantes. A análise de regressão múltipla explicou 62% do desempenho na corrida (p<0,05). A análise de regressão linear simples mostrou que a DCpa correspondeu a 45%, estatura 33%, Ctíbia 24% e MC 3%, do desempenho na corrida (p<0,05). A análise de cluster mostrou que o grupo de baixa velocidade apresentava maior MC, IMC e DCpa (p<0,05), e o grupo de alta velocidade apresentava maior estatura, Ctíbia e menor DCpa (p<0,05). Conclui-se que as medidas antropométricas podem predizer o desempenho da corrida.

The aim of this study was to determine the effects of anthropometric characteristics on sprint. It was measured the height, body mass (BM), body mass index (BMI), calf skin fold (CKF), tibia's length (TL) and running velocity (50m) of 235 students. The multiple regression explain 62% of 50 m running performance (p<0.05). The simple linear regression showed that CKF represented 45%, height 33%, TL 24%, and BM 3% of 50m running performance (p<0.05). The cluster analyze showed that the low velocity group presented highest BM, BMI and CKF (p< 0,05), while the high velocity group presented the highest stature, TL and the lowest CKF (p< 0,05). The results suggest that anthropometric variables used in the current study can significantly predict the 50 m sprint in young people.

El estudio trata de evaluar los efectos de las características antropométricas en la carrera de velocidad. Fue evaluado la altura, masa corporal (MC), índice de masa corporal (IMC), pliegue cutáneo del pantorrilla (DCpa), longitud de la tibia (Ctíbia) y la carrera de velocidad (50m) de 235 estudiantes. El analisis de regresión múltiple explica el 62% del rendimiento en la carrera (p <0,05). El análisis de regresión lineal simple mostró que correspondía a 45% DCpa, 33% altura, 24% Ctíbia y 3% MC, el rendimiento en la carrera (p <0,05). El análisis de conglomerados mostró que el grupo de baja velocidad tuvo un mayor MC, DCpa y el IMC (p <0,05), y el grupo de alta velocidad mostró una mayor altura, Ctíbia, e inferior DCpa (p <0,05). Se concluye que las medidas antropométricas puede predecir el rendimiento de la carrera.