Impact of COVID-19 Confinement on Physical Activity and Sedentary Behaviour in Spanish University Students: Role of Gender.

During the COVID-19 pandemic, entire populations were instructed to live in home-confinement to prevent the expansion of the disease. Spain was one of the countries with the strictest conditions, as outdoor physical activity was banned for nearly two months. This study aimed to analyse the changes in physical activity and sedentary behaviours in Spanish university students before and during the confinement by COVID-19 with special focus on gender. We also analysed enjoyment, the tools used and motivation and impediments for doing physical activity. An online questionnaire, which included the International Physical Activity Questionnaire Short Form and certain "ad hoc" questions, was designed. Students were recruited by distributing an invitation through the administrative channels of 16 universities and a total of 13,754 valid surveys were collected. Overall, university students reduced moderate (-29.5%) and vigorous (-18.3%) physical activity during the confinement and increased sedentary time (+52.7%). However, they spent more time on high intensity interval training (HIIT) (+18.2%) and mind-body activities (e.g., yoga) (+80.0%). Adaptation to the confinement, in terms of physical activity, was handled better by women than by men. These results will help design strategies for each gender to promote physical activity and reduce sedentary behaviour during confinement periods.

Metabotropic Glutamate Receptor 2 and Dopamine Receptor 2 Gene Expression Predict Sensorimotor Gating Response in the Genetically Heterogeneous NIH-HS Rat Strain.

Disruption of sensorimotor gating causes "flooding" of irrelevant sensory input and is considered a congenital trait in several neurodevelopmental disorders. Prepulse inhibition of acoustic startle response (PPI) is the operational measurement and has a high translational validity. Pharmacological studies in rodents have linked alterations in serotonin, dopamine and glutamate signalling to PPI disruption. How PPI response is associated with gene expression levels of these receptors is unknown. PPI response was assessed in 39 genetically heterogeneous National Institutes of Health-Heterogeneous Stock (NIH-HS) rats. Animals were classified as high, medium or low PPI. Expression levels of glutamate metabotropic receptor 2 (Grm2), dopamine receptor D2 (Drd2), dopamine receptor D1 (Drd1), serotonin receptor 1A (Htr1a), serotonin receptor 2A (Htr2a) and homer scaffolding protein 1 (Homer1) were investigated in prefrontal cortex (PFC) and striatum (STR). When comparing the two extreme phenotypes, only Drd2 in STR showed increased expression in the low PPI group. A multinomial model fitting all genes and all groups indicated that Grm2 in PFC, and Grm2 and Drd2 in the STR predicted PPI group. This was corroborated by a linear relationship of Grm2 with PPI in PFC, and Drd2 with PPI in STR. An interaction between levels of H3K27 trimethylation, associated with transcriptional repression, and PPI phenotype was observed for Drd2 in STR. Gene set enrichment analysis on a microarray dataset on Lewis rats confirmed enrichment of Drd2 in PFC in relation to PPI. These findings contribute to the understanding of the genetic substrate behind alterations in sensorimotor gating, relevant for its linkage to neurodevelopmental disorders.

Inalambric Biofeedback Devices to Analyze Strength Manifestation in Military Population.

The study of the effect of stress on both combatants physiological and anatomical systems have been poor studied in the specific literature. The present research aimed to study the effect of combat stress in strength manifestations of leg flexor-extensor muscles and the anaerobic metabolism of soldiers. Before and after asymmetrical combat simulation were analyzed parameters of blood lactate concentration, explosive leg strength manifestation and contractile capacity of leg muscle in 186 professional soldiers. Results showed a significant increase (p < 0.05) in blood lactate values (2.23 ± 0.95 vs 7.47 ± 3.67 mmol/L), explosive leg strength (Squat Jump 0.31 ± 0.06 vs 0.35 ± 0.07 m, Countermovement Jump 0.33 ± 0.07 vs 0.36 ± 0.07 m, Abalakov Jump 0.39 ± 0.08 vs 0.41 ± 0.09 m), and a significant decrease of the elastic capacity (0.022 ± 0.04 vs 0.021 ± 0.04) and recruitment and muscle synchronization capability (0.028 ± 0.04 vs 0.026 ± 0.04). This data suggest that combat stress increases the leg strength manifestation despite the significantly increase of muscle acidosis after a combat simulation. This result is probably due to the high activation of the fight-flight system of soldiers which increases the organic response of soldiers and that can compensate the prejudicial effect of acidosis in muscle contraction. These results could be used by officers to improve specific training programs and to improve planning and election of equipment and material for the development of different missions in current theaters of operations.