Circadian effects of training

Background: Some physiological responses such as circulating glucose as well as muscle performance show a circadian rhythmicity. In the present study we aimed to quantitatively synthesize the data comparing the metabolic adaptations induced by morning and afternoon training. Methods: PubMed, SCOPUS, and Web of Science databases were systematically searched for studies comparing the metabolic adaptations (> 2 weeks) between morning and afternoon training. A meta-analysis was performed using random-effects models with DerSimonian-Laird methods for fasting blood glucose, hemoglobin A1c (HbAc1), homeostatic model assessment (HOMA), insulin, triglycerides, total cholesterol, low-density lipoprotein (LDL), and high-density lipoprotein (HDL). Results: We identified 9 studies with 11 different populations (n = 450 participants). We found that afternoon exercise was more effective at reducing circulating triglycerides [standardized mean difference (SMD) - 0.32; 95% confidence interval (CI) - 0.616 to - 0.025] than morning training. Moreover, afternoon tended to decrease fasting blood glucose (SMD - 0.24; 95% CI - 0.478 to 0.004) to a greater extent than morning training. Conclusion: Metabolic adaptations to exercise may be dependent on the time of day. Morning training does not show superior effects to afternoon exercise in any of the analyzed outcomes. However, afternoon training is more effective at reducing circulating triglyceride levels and perhaps at reducing fasting blood glucose than morning training. The study was preregistered at PROSPERO (CRD42021287860)

The role of muscle disuse in muscular and cardiovascular fitness: A systematic review and meta‐regression

We aimed to assess the effects of muscle disuse on muscle strength (MS), muscle mass (MM) and cardiovascular fitness. Databases were scrutinized to identify human studies assessing the effects of muscle disuse on both (1) MM and (2) maximal oxygen uptake (VO2max) and/or MS. Random-effects meta-analysis and meta-regression with initial physical fitness and length of the protocol as a priori determined moderators were performed. We quantitatively analyzed 51 different studies, and the level of significance was set at p < 0.05. Data from the participants in 14 studies showed a decline in both VO2max (SMD: −0.93; 95% CI: −1.27 to −0.58) and MM (SMD: −0.34; 95% CI: −0.57 to −0.10). Data from 47 studies showed a decline in strength (−0.88; 95% CI: −1.04 to −0.73) and mass (SMD: −0.47; 95% CI: −0.58 to −0.36). MS loss was twice as high as MM loss, but differences existed between anatomical regions. Notably, meta-regression analysis revealed that initial MS was inversely associated with MS decline. VO2max and MS decline to a higher extent than MM during muscle disuse. We reported a more profound strength loss in subjects with high muscular strength. This is physiologically relevant for athletes because their required muscular strength can profoundly decline during a period of muscle disuse. It should however be noted that a period of muscle disuse can have devastating consequences in old subjects with low muscular strength.ERDF, Grant PID2022‐140453OB‐I00MICIU/AEI/10.13039/501100011033, Grant PID2022-140453OB-I0

Stay Fit, Stay Young: Mitochondria in Movement: The Role of Exercise in the New Mitochondrial Paradigm

Skeletal muscles require the proper production and distribution of energy to sustain their work. To ensure this requirement is met, mitochondria form large networks within skeletal muscle cells, and during exercise, they can enhance their functions. In the present review, we discuss recent findings on exercise-induced mitochondrial adaptations. We emphasize the importance of mitochondrial biogenesis, morphological changes, and increases in respiratory supercomplex formation as mechanisms triggered by exercise that may increase the function of skeletal muscles. Finally, we highlight the possible effects of nutraceutical compounds on mitochondrial performance during exercise and outline the use of exercise as a therapeutic tool in noncommunicable disease prevention. The resulting picture shows that the modulation of mitochondrial activity by exercise is not only fundamental for physical performance but also a key point for whole-organism well-being.The CNIC is supported by the Instituto de Salud Carlos III (ISCIII), the Ministerio de Ciencia, Innovación y Universidades (MCNU), and the Pro CNIC Foundation and is a Severo Ochoa Center of Excellence (SEV-2015-0505)

Physiological Benefits and Performance of Sea Water Ingestion for Athletes in Endurance Events: A Systematic Review

In different endurance events, athletes have limited access to fluid intake, such as ultraendurance running. For this reason, it is necessary to establish an adequate hydration strategy for this type of long-duration sporting event. Indeed, it seems that the intake of seawater is a suitable hydration alternative to improve post-exercise recovery in this type of endurance event. This seawater is characterized by being a deep natural mineral water of moderate mineralization, which is usually extracted from a depth of about 700 m. Therefore, the aim of this systematic review is to evaluate the efficacy of seawater consumption in both performance and post-exercise recovery in long-duration sport events. A systematic and comprehensive literature search was performed in PubMed, Scopus, andWeb of Science in September 2022. Initially, 8 out of 558 articles met the inclusion criteria. Among these eight studies, six were randomized clinical trials, and two were observational studies (one cross-sectional and one prospective study in well-conditioned student athletes). The results showed that deep sea water consumption accelerated the recovery of aerobic capacity and leg muscle capacity on running performance. In addition, the lactate production after the running exercise in seawater was significantly lower than in pure water. In conclusion, the present review demonstrates that seawater consumption could significantly improve the capacity of recovery after exercise."Fundacion Ramon Areces", Madrid, SpainConsejo Nacional de Ciencia y Tecnologia (CONACyT) 218582/47197

Effects of hydroxytyrosol dose on the redox status of exercised rats: the role of hydroxytyrosol in exercise performance

Background: Hydroxytyrosol (HT) is a polyphenol found in olive oil that is known for its antioxidant effects. Here, we aimed to describe the effects of a low and high HT dose on the physical running capacity and redox state in both sedentary and exercised rats. Methods: Male Wistar rats were allocated into 6 groups: sedentary (SED; n = 10); SED consuming 20 mg/kg/d HT (SED20; n = 7); SED consuming 300 mg/kg/d HT (SED300; n = 7); exercised (EXE; n = 10); EXE consuming 20 mg/kg/d HT (EXE20; n = 10) and EXE consuming 300 mg/kg/d HT (EXE300; n = 10). All the interventions lasted 10 weeks; the maximal running velocity was assessed throughout the study, whereas daily physical work was monitored during each training session. At the end of the study, the rats were sacrificed by bleeding. Hemoglobin (HGB) and hematocrit (HCT) were measured in the terminal blood sample. Moreover, plasma hydroperoxide (HPx) concentrations were quantified as markers of lipid peroxidation. Results: In sedentary rats, HT induced an antioxidant effect in a dose-dependent manner without implications on running performance. However, if combined with exercise, the 300 mg/kg/d HT dosage exhibited a pro-oxidant effect in the EXE300 group compared with the EXE and EXE20 groups. The EXE20 rats showed a reduction in daily physical work and a lower maximal velocity than the EXE and EXE300 rats. The higher physical capacity exhibited by the EXE300 group was achieved despite the EXE300 rats expressing lower HGB levels and a lower HCT than the EXE20 rats. Conclusions: Our results suggest that a high HT dose induces a systemic pro-oxidant effect and may prevent the loss of performance that was observed with the low HT dose.This study was supported by the grant #3650 managed by Fundación General Empresa-Universidad de Granada, and by the investigation group CTS-454 “Impacto fisiológico del estrés oxidativo, deporte, actividad física y salud

Ergogenic effects of quercetin supplementation in trained rats

[Background] Quercetin is a natural polyphenolic compound currently under study for its ergogenic capacity to improve mitochondrial biogenesis. Sedentary mice have exhibited increased endurance performance, but results are contradictory in human models. [Methods] We examined the effects of six weeks of endurance training and quercetin supplementation on markers of endurance performance and training in a rodent model. Rats were randomly assigned to one of the following groups: placebo+sedentary (PS), quercetin+sedentary (QS), placebo+endurance training (PT) and quercetin+endurance training (QT). Quercetin was administered at a dose of 25 mg/kg on alternate days. During six weeks of treatment volume parameters of training were recorded, and after six weeks all groups performed a maximal graded VO2 max test and a low-intensity endurance run-to-fatigue test. [Results] No effects were found in VO2 peak (p>0.999), nor in distance run during low-intensity test, although it was 14% greater in QT when compared with PT (P = 0.097). Post-exercise blood lactate was increased in QT when compared with PT (p=0.023) and also in QS compared with PS (p=0.024). [Conclusions] This study showed no effects in VO2 peak, speed at VO2 peak or endurance time to exhaustion after six weeks of quercetin supplementation compared with placebo in trained rats. Quercetin was show to increase blood lactate production after high-intensity exercise

High-intensity high-volume swimming induces more robust signaling through PGC-1α and AMPK activation than sprint interval swimming in <i>m. triceps brachii</i>

We aimed to test whether high-intensity high-volume training (HIHVT) swimming would induce more robust signaling than sprint interval training (SIT) swimming within the m. triceps brachii due to lower metabolic and oxidation. Nine well-trained swimmers performed the two training procedures on separate randomized days. Muscle biopsies from m. triceps brachii and blood samples were collected at three different time points: a) before the intervention (pre), b) immediately after the swimming procedures (post) and c) after 3 h of rest (3 h). Hydroperoxides, creatine kinase (CK), and lactate dehydrogenase (LDH) were quantified from blood samples, and peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) and the AMPKpTHR172/AMPK ratio were quantified by Western blot analysis. PGC-1α, sirtuin 3 (SIRT3), superoxide-dismutase 2 (SOD2), and vascular endothelial growth factor (VEGF) mRNA levels were also quantified. SIT induced a higher release of LDH (

Autoimagen en las dos primeras fases de la adolescencia y factores relacionados

Se trata de la descripción de la imagen corporal en un amplio grupo de alumnos escolarizados en Cantabria (n=1179 adolescentes), de 10 a 17 años de edad (adolescencia temprana e intermedia) dentro de un estudio más amplio encaminado a evidenciar un estilo de vida saludable en estos adolescentes, llevado a cabo por profesores de universidad y profesores de educación física de los centros educativos. Los principales hallazgos consisten en que los adolescentes tienen, en general, una buena imagen de sí mismos y, aunque no reconocen la elevada prevalencia de sobrepeso y obesidad, desean adelgazar y el grado de satisfacción que tienen con su imagen corporal va empeorando conforme avanza la adolescencia, signifi cativamente más en las del sexo femenino. Esta insatisfacción debe ser tenida en cuenta en el abordaje de los adolescentes con obesidad

Mitochondrial Function and Signaling to Regulate Cellular Life

Mitochondria are essential organelles found in nearly all eukaryotic cells, responsible for producing the energy that drives cellular processes [...

Food made us human: Recent genetic variability and its relevance to the current distribution of macronutrients

Numerous dietary strategies are currently used for the prevention of metabolic diseases and for weight loss. Some of the strategies that are used do not have an appropriate physiological-nutritional basis and do not take into account the genetic changes that have occurred recently. Thus, in certain cases, they can be harmful to human health. This review aims to explain the genetic mutations that have occurred during human evolution from the first hominids to Homo sapiens and to explain how they have influenced the way we feed ourselves. Some mutations favored brain development and others are related to the digestion of nutrients such as lactose and starch. The influence of the domestication of food and the practice of cooking on human nutrition is also explained. In addition, this review intends to justify the current recommendations on the caloric distribution of macronutrients based on the important influence of genetic changes and adaptations that have occurred in our species