Core training impacts running athletes' physical capacity / Impactos do treinamento no core sobre a capacidade física em atletas de corrida / Impacto del entrenamiento del core en la capacidad física de los atletas que corren

ABSTRACT Introduction: Core strength training focuses mainly on the muscle group and neuromuscular system of the central area of the human body to gain strength and stability for complex movements. Studies have reported the effect of core training on high-capacity athletes, but there is still a gap regarding the impacts on physical capacity in running athletes. Objective: To study the effects of strength training on athletes' core and the direct impacts on running quality. Methods: Athletes of the men's running team at the athletic training center of the Institute of Physical Education were core strength trained for 10 to 12 weeks. After the period, physical tests, according to predetermined protocols. The data were compared before, after the intervention, and after statistical treatment, and the findings were discussed according to the scientific literature. Results: After 12 weeks of training, among the five sports skills, there was only a significant difference before and after training of body lateral flexion (right side) (P<0.05), and there was no significant difference before and after training of the other four sport skills (P > 0.05). Conclusions: Through the static and dynamic exercises of core strength training, we can effectively improve the proprioception intervention in body movement so that runners can more accurately control their joints and muscles, ensuring movement and postural accuracy. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução: O treinamento de força do core concentra-se principalmente no grupo muscular e no sistema neuromuscular da área central do corpo humano, com o propósito de ganho de força e estabilidade para movimentos complexos. Estudos relatam o efeito do treinamento do core em atletas de alta capacidade, porém ainda há uma lacuna quanto aos impactos sobre a capacidade física em atletas de corrida. Objetivo: Estudar os efeitos resultantes do treinamento de força no core dos atletas e os impactos diretos na qualidade da corrida. Métodos: Os atletas da equipe masculina de corrida, no centro de treinamento de atletismo do Instituto de Educação Física, foram treinados com força fundamental por 10 a 12 semanas. Após o período, testes físicos, segundo protocolos pré-determinados, foram executados. Os dados foram comparados antes e após a intervenção, após o tratamento estatístico, os achados foram discutidos segundo a literatura cientifica. Resultados: Após 12 semanas de treinamento, entre as cinco habilidades esportivas, houve apenas diferença significativa antes e depois do treinamento de flexão lateral corporal (lado direito) (P<0,05), e não houve diferença significativa antes e depois do treinamento das outras quatro habilidades esportivas (P > 0,05). Conclusão: Através dos exercícios estáticos e dinâmicos do treinamento de força do core, podemos melhorar efetivamente a intervenção da propriocepção no movimento corporal, para que os corredores possam controlar com mais precisão as articulações e músculos, garantindo a precisão do movimento e postural. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción: El entrenamiento de la fuerza del core se concentra principalmente en el grupo muscular y en el sistema neuromuscular de la zona central del cuerpo humano, con el fin de ganar fuerza y estabilidad para los movimientos complejos. Los estudios han informado sobre el efecto del entrenamiento del tronco en los atletas de alta capacidad, pero todavía hay un vacío en cuanto a los impactos en la capacidad física en los atletas que corren. Objetivo: Estudiar los efectos resultantes del entrenamiento de fuerza en el core de los atletas y los impactos directos en la calidad de la carrera. Métodos: Los atletas del equipo masculino de atletismo, en el centro de entrenamiento de atletismo del Instituto de Educación Física, fueron entrenados con fuerza central durante 10 a 12 semanas. Tras el periodo, se ejecutaron pruebas físicas, según protocolos predeterminados. Los datos se compararon antes y después de la intervención, tras el tratamiento estadístico, los resultados se discutieron de acuerdo con la literatura científica. Resultados: Después de 12 semanas de entrenamiento, entre las cinco habilidades deportivas, sólo hubo diferencia significativa antes y después del entrenamiento de la flexión lateral del cuerpo (lado derecho) (P<0,05), y no hubo diferencia significativa antes y después del entrenamiento de las otras cuatro habilidades deportivas (P > 0,05). Conclusiones: A través de ejercicios estáticos y dinámicos de entrenamiento de la fuerza del core, podemos mejorar eficazmente la intervención de la propiocepción en el movimiento del cuerpo, de modo que los corredores puedan controlar con mayor precisión las articulaciones y los músculos, asegurando la precisión del movimiento y la postura. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

Muscle injury and sports rehabilitation management in endurance training oriented to winter sports / Lesão muscular e gerenciamento da reabilitação esportiva no treinamento de resistência direcionado aos esportes de inverno / Gestión de las lesiones musculares y de la rehabilitación deportiva en el entrenamiento de resistencia dirigido a los deportes de invierno

ABSTRACT Introduction: Muscle injury in ski sports training has gradually increased, greatly impairing performance in ice and snow sports competitions. Objective: To study muscle injury and muscle movement during ice and snow sports training and the rehabilitation of muscle injuries. Methods: Thirty skiers with knee muscle injuries were selected as subjects and underwent rehabilitation training for six weeks, and the indicators were statistically evaluated. Results: The ski injuries were mainly muscle strain, muscle or ligament strain, and ligament rupture. The indices after treatment were significantly different from those before treatment (P < 0.05); compared with the three rehabilitation programs, the improvement of each index in group C was significantly different from that in the other two groups (P < 0.05), while there was no significant difference in the improvement of each index between the multi-angle isometric training treatment in group A and the proprioceptive neuromuscular stimulation technique in group B (P>0.05). Conclusion: The influence of recovery training technology on knee muscle re-education was proposed, and a rehabilitation plan for skiing was presented. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução: O quadro de lesão muscular no treinamento esportivo de esqui tem aumentado gradualmente, prejudicando muito o desempenho das competições esportivas de gelo e neve. Objetivo: Estudar a lesão muscular e o movimento muscular durante o treinamento esportivo no gelo e na neve, bem como a reabilitação das lesões musculares. Métodos: Trinta esquiadores com lesão muscular no joelho foram selecionados como sujeitos e submetidos a treinamento de reabilitação por um total de 6 semanas, tendo os indicadores sido avaliados estatisticamente. Resultados: Os tipos de lesões no esqui foram principalmente tensão muscular, tensão muscular ou ligamentar e ruptura ligamentar. Os índices após o tratamento foram significativamente diferentes daqueles antes do tratamento (P < 0,05); comparado com os três programas de reabilitação, a melhora de cada índice no grupo C foi significativamente diferente da dos outros dois grupos (P < 0,05), enquanto não houve diferença significativa na melhora de cada índice entre o tratamento de treinamento isométrico multiangular no grupo A e a técnica de estimulação neuromuscular proprioceptiva no grupo B (P>0,05). Conclusão: A influência da tecnologia de treinamento de recuperação na reeducação muscular do joelho foi proposta, e foi apresentado um plano de reabilitação para a prática de esqui. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción: El cuadro de lesiones musculares en el entrenamiento de los deportes de esquí ha ido aumentando progresivamente, lo que perjudica en gran medida el rendimiento en las competiciones de deportes de hielo y nieve. Objetivo: Estudiar las lesiones musculares y el movimiento muscular durante el entrenamiento de los deportes de hielo y nieve, así como la rehabilitación de las lesiones musculares. Métodos: Se seleccionaron como sujetos treinta esquiadores con lesiones musculares en la rodilla y se sometieron a un entrenamiento de rehabilitación durante un total de 6 semanas, y se evaluaron estadísticamente los indicadores. Resultados: Los tipos de lesiones de esquí fueron principalmente la distensión muscular, la distensión muscular o de ligamentos y la rotura de ligamentos. Los índices después del tratamiento fueron significativamente diferentes de los anteriores (P < 0,05); en comparación con los tres programas de rehabilitación, la mejora de cada índice en el grupo C fue significativamente diferente de la de los otros dos grupos (P < 0,05), mientras que no hubo diferencias significativas en la mejora de cada índice entre el tratamiento de entrenamiento isométrico multiángulo en el grupo A y la técnica de estimulación neuromuscular propioceptiva en el grupo B (P>0,05). Conclusión: Se propuso la influencia de la tecnología de entrenamiento de recuperación en la reeducación muscular de la rodilla y se presentó un plan de rehabilitación para el esquí. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

The Effects of Six Weeks of Endurance Training and CGRP Inhibition on Nrf2 and AKT Expression in the Hippocampal Tissue of Male Wistar Rats.

Purpose: To study the effects of a six-week endurance training protocol and calcitonin gene-related peptide (CGRP) inhibition on the nuclear factor erythroid 2-related factor 2 (Nrf2) and protein kinase B (PKB) or AKT expression in the hippocampal tissue of male Wistar rats. Main Methods. Building on a controlled experimental design with a posttest, 28 healthy Wistar male rats were randomly assigned to four groups (n = 7 per group), including control, control+CGRP inhibition, endurance training, and endurance training+CGRP inhibition groups. The training groups were trained for six weeks. Rats in the CGRP inhibition group received CGRP receptor antagonist daily (0.25 mg/kg) via intravenous (IV) injection. The Nrf2 and AKT (PKB) expression was measured using the real-time PCR technique. Results: In the endurance training group, Nrf2 expression in the hippocampal tissue was increased significantly more than in other groups (P < 0.05). There was also a significant increase in the AKT expression in the endurance training group compared to the control group (P = 0.048) and in the endurance training+CGRP inhibition compared to the control group (P = 0.012). In addition, there was no significant relationship between AKT (PKB) and Nrf2 (r = -0.27, n = 28, P = 0.16). Conclusion: Endurance training alone has been able to increase Nrf2 and AKT (PKB) mRNA levels in the hippocampal tissue, considering that endurance training had no significant effect on AKT and Nrf2 expression after adding to CGRP inhibition.

Respiratory muscle endurance training improves exercise performance but does not affect resting blood pressure and sleep in healthy active elderly.

PURPOSE: Ageing is associated with increased blood pressure (BP), reduced sleep, decreased pulmonary function and exercise capacity. The main purpose of this study was to test whether respiratory muscle endurance training (RMET) improves these parameters. METHODS: Twenty-four active normotensive and prehypertensive participants (age: 65.8 years) were randomized and balanced to receive either RMET (N = 12) or placebo (PLA, N = 12). RMET consisted of 30 min of volitional normocapnic hyperpnea at 60% of maximal voluntary ventilation while PLA consisted of 1 inhalation day-1 of a lactose powder. Both interventions were performed on 4-5 days week-1 for 4-5 weeks. Before and after the intervention, resting BP, pulmonary function, time to exhaustion in an incremental respiratory muscle test (incRMET), an incremental treadmill test (IT) and in a constant-load treadmill test (CLT) at 80% of peak oxygen consumption, balance, sleep at home, and body composition were assessed. Data was analyzed with 2 × 2 mixed ANOVAs. RESULTS: Compared to PLA, there was no change in resting BP (independent of initial resting BP), pulmonary function, IT performance, sleep, body composition or balance (all p > 0.05). Performance significantly increased in the incRMET (+ 6.3 min) and the CLT (+ 3.2 min), resulting in significant interaction effects (p < 0.05). CONCLUSION: In the elderly population, RMET might be used to improve respiratory and whole body endurance performance either as an adjunct to physical exercise training or as a replacement thereof for people not being able to intensively exercise even if no change in BP or sleep may be expected.

Endurance exercise ameliorates phenotypes in Drosophila models of spinocerebellar ataxias.

Endurance exercise is a potent intervention with widespread benefits proven to reduce disease incidence and impact across species. While endurance exercise supports neural plasticity, enhanced memory, and reduced neurodegeneration, less is known about the effect of chronic exercise on the progression of movement disorders such as ataxias. Here, we focused on three different types of ataxias, spinocerebellar ataxias type (SCAs) 2, 3, and 6, belonging to the polyglutamine (polyQ) family of neurodegenerative disorders. In Drosophila models of these SCAs, flies progressively lose motor function. In this study, we observe marked protection of speed and endurance in exercised SCA2 flies and modest protection in exercised SCA6 models, with no benefit to SCA3 flies. Causative protein levels are reduced in SCA2 flies after chronic exercise, but not in SCA3 models, linking protein levels to exercise-based benefits. Further mechanistic investigation indicates that the exercise-inducible protein, Sestrin (Sesn), suppresses mobility decline and improves early death in SCA2 flies, even without exercise, coincident with disease protein level reduction and increased autophagic flux. These improvements partially depend on previously established functions of Sesn that reduce oxidative damage and modulate mTOR activity. Our study suggests differential responses of polyQ SCAs to exercise, highlighting the potential for more extensive application of exercise-based therapies in the prevention of polyQ neurodegeneration. Defining the mechanisms by which endurance exercise suppresses polyQ SCAs will open the door for more effective treatment for these diseases.

Effect of short-term hindlimb immobilization on skeletal muscle atrophy and the transcriptome in a low compared with high responder to endurance training model.

Skeletal muscle atrophy is a physiological response to disuse, aging, and disease. We compared changes in muscle mass and the transcriptome profile after short-term immobilization in a divergent model of high and low responders to endurance training to identify biological processes associated with the early atrophy response. Female rats selectively bred for high response to endurance training (HRT) and low response to endurance training (LRT; n = 6/group; generation 19) underwent 3 day hindlimb cast immobilization to compare atrophy of plantaris and soleus muscles with line-matched controls (n = 6/group). RNA sequencing was utilized to identify Gene Ontology Biological Processes with differential gene set enrichment. Aerobic training performed prior to the intervention showed HRT improved running distance (+60.6 ± 29.6%), while LRT were unchanged (-0.3 ± 13.3%). Soleus atrophy was greater in LRT vs. HRT (-9.0 ±8.8 vs. 6.2 ±8.2%; P<0.05) and there was a similar trend in plantaris (-16.4 ±5.6% vs. -8.5 ±7.4%; P = 0.064). A total of 140 and 118 biological processes were differentially enriched in plantaris and soleus muscles, respectively. Soleus muscle exhibited divergent LRT and HRT responses in processes including autophagy and immune response. In plantaris, processes associated with protein ubiquitination, as well as the atrogenes (Trim63 and Fbxo32), were more positively enriched in LRT. Overall, LRT demonstrate exacerbated atrophy compared to HRT, associated with differential gene enrichments of biological processes. This indicates that genetic factors that result in divergent adaptations to endurance exercise, may also regulate biological processes associated with short-term muscle unloading.

Training-intensity Distribution on Middle- and Long-distance Runners: A Systematic Review.

Training-intensity distribution (TID) is considered the key factor to optimize performance in endurance sports. This systematic review aimed to: I) characterize the TID typically used by middle-and long-distance runners; II) compare the effect of different types of TID on endurance performance and its physiological determinants; III) determine the extent to which different TID quantification methods can calculate same TID outcomes from a given training program. The keywords and search strategy identified 20 articles in the research databases. These articles demonstrated differences in the quantification of the different training-intensity zones among quantification methods (i. e. session-rating of perceived exertion, heart rate, blood lactate, race pace, and running speed). The studies that used greater volumes of low-intensity training such as those characterized by pyramidal and polarized TID approaches, reported greater improvements in endurance performance than those which used a threshold TID. Thus, it seems that the combination of high-volume at low-intensity (≥ 70% of overall training volume) and low-volume at threshold and high-intensity interval training (≤ 30%) is necessary to optimize endurance training adaptations in middle-and long-distance runners. Moreover, monitoring training via multiple mechanisms that systematically encompasses objective and subjective TID quantification methods can help coaches/researches to make better decisions.

Long-Term Passive Leg Stretch Improves Systemic Vascular Responsiveness as Much as Single-Leg Exercise Training.

PURPOSE: The current study compared the local and systemic vascular responsiveness after small muscle mass endurance training or passive stretching training (PST). METHODS: Thirty-six sex-matched healthy participants underwent 8-wk single-leg knee extension (SLKE) (n = 12) training or PST (n = 12), or no intervention (control, n = 12). Before and after the intervention, local and systemic vascular responsiveness was assessed by Doppler ultrasound at the femoral (local effect) and brachial artery (systemic effect) during single passive leg movement and brachial flow-mediated dilation (FMD) test, respectively. RESULTS: After training, delta femoral blood flow (representing the local vascular responsiveness) increased after SLKE and PST by +54 (7)% (effect size, 2.72; P < 0.001) and +20 (2)% (effect size, 2.43; P < 0.001), respectively, albeit with a greater extent in SLKE (post-SLKE vs post-PST: +56 [8]% [effect size, 2.92; P < 0.001]). Interestingly, the %FMD (standing for the systemic effect) increased after SLKE and PST by +12 (2)% (effect size, 0.68; P < 0.001) and +11 (1)% (effect size, 0.83; P < 0.001), respectively, without any between-groups difference (P > 0.05). No changes occurred in control. CONCLUSIONS: The present findings revealed that both active and passive training modalities induced similar improvements in the brachial artery dilatation capacity, whereas the former was more effective in improving femoral artery blood flow. Passive stretching could be used in people with limited mobility to improve vascular responsiveness both at the local and systemic level and in this latter case has similar effects as small muscle mass endurance training.

Effects of Combined Strength and Endurance Training on Body Composition, Physical Fitness, and Serum Hormones During a 6-Month Crisis Management Operation.

ABSTRACT: Pihlainen, K, Kyröläinen, H, Santtila, M, Ojanen, T, Raitanen, J, and Häkkinen, K. Effects of combined strength and endurance training on body composition, physical fitness, and serum hormones during a 6-month crisis management operation. J Strength Cond Res 36(9): 2361-2370, 2022-Very few studies have examined the impact of training interventions on soldier readiness during an international military operation. Therefore, the present study investigated the effects of combined strength and endurance training on body composition, physical performance, and hormonal status during a 6-month international military deployment consisting of typical peacekeeping tasks, e.g., patrolling, observation, and on-base duties. Soldiers ( n = 78) were randomly allocated to a control group (C) or one of 3 combined whole-body strength and endurance training groups with varying strength-to-endurance training emphasis (Es = 25/75%, SE = 50/50% or Se = 75/25% of strength/endurance training). Body composition, physical performance (3000-m run, standing long jump [SLJ], isometric maximal voluntary contraction of the lower [MVC lower] and upper extremities [MVC upper ], muscle endurance tests), and selected serum hormone concentrations were determined prior to training (PRE), and after 9 (MID) and 19 (POST) weeks of training. Within- and between-group changes were analyzed using linear regression models. The average combined strength and endurance training frequency of the total subject group was 3 ± 2 training sessions per week. No changes were observed in physical performance variables in the intervention groups, whereas SLJ decreased by 1.9% in C ( p < 0.05). Maximal voluntary contraction lower increased by 12.8% in the combined intervention group ( p < 0.05), and this was significantly different to C ( p < 0.05). Testosterone-to-cortisol ratio increased in SE and Se ( p < 0.05), whereas no change was observed in C. The intervention groups maintained or improved their physical performance during deployment, which is beneficial for operational readiness. However, the high interindividual variation observed in training adaptations highlights the importance of training individualization during prolonged military operations.

Fallo muscular en la hipertrofia con entrenamiento de contra resistencia: una revisión sistemática / Muscle failure in hypertrophy with resistance training: a systematic review

RESUMEN Objetivo: Determinar cuáles son los efectos que tiene el fallo muscular en el desarrollo de la hipertrofia en el entrenamiento de contra resistencia. Métodos: Estudio de tipo revisión sistemática, es decir, de enfoque cualitativo y de diseño no experimental. Se realizó una búsqueda sistemática en cinco bases de datos (Pubmed, Google Académico, ScienceDirect, Scopus, Sportdiscus). Después de analizar 405 estudios, fue preciso considerar su utilidad y relevancia con respecto a la revisión, así como también la credibilidad o experiencia del autor en la temática. Resultados: Después del cribado correspondiente y la evaluación metodológica 9 estudios cumplieron con los criterios de inclusión, según lo obtenido de esta revisión la utilización del Fallo Muscular (FM) no mostró beneficios adicionales en el aumento de la masa muscular. Además, se mostró que no existen diferencias significativas cuando se comparan cargas altas y bajas utilizando esta variable. Conclusión: Se determinó que la variable volumen es más importante en desarrollos hipertróficos independientemente de si un ejercicio se ejecuta o no hacia el fallo muscular, asimismo, es más beneficioso para la hipertrofia cuando las repeticiones no se llevan al fallo muscular si no se dejan cerca de este.

ABSTRACT Objective: To determine what are the effects of muscle failure on the development of hypertrophy in counter resistance training. Method: It is a systematic review type of study, that is, with a qualitative approach and a non-experimental design. A systematic search was carried out in 5 databases (Pubmed, Google Scholar, ScienceDirect, Scopus, Sportdiscus). After analyzing 405 studies, it was necessary to consider their usefulness and relevance in respect of the review, as well as the credibility or experience of the author on the subject. Results: After the corresponding screening and methodological evaluation, 9 studies met the inclusion criteria, as obtained from this review, the use of Muscle Failure (FM) did not show additional benefits in increasing muscle mass. In addition, it was shown that there are no significant differences when comparing high and low loads using this variable. Conclusion: It was determined that the volume variable is more important in hypertrophic developments regardless of whether or not an exercise is executed towards muscle failure, it is also more beneficial for hypertrophy when repetitions do not lead to muscle failure but are close to it.

Effect of varied plyometric training in land and aquatic medium on anaerobic power of athletes / Efeito do treinamento pliométrico variado em meio terrestre e aquático na potência anaeróbia de atletas

ABSTRACT The aim of the present study was to find out the effect of varied plyometric training (land plyometric training, aqua plyometric training and weighted vest aqua-plyometric training) on anaerobic power of school athletes. A total of forty eight (n= 48) district level school athletes were randomly selected. All the subjects were divided into four equal groups: i) land plyometric training group (n=12), ii) aqua plyometric training group (n=12), iii) aqua-plyometric training with weighted vest group (n=12) and iv) control group (n=12). The varied plyometric training was intervened for fourteen weeks in the respective training groups. In the present study, anaerobic power was considered as the dependent variable, and it was measured by Margaria-Kalamen power test. To draw statistical inferences on anaerobic power among the groups in pre and post intervention conditions, ANCOVA was used, followed by Tukey's LSD post-hoc test. The significance of the means was tested at the 0.05 level. Different plyometric training groups improved significantly with respect to the control group in anaerobic power. Therefore, various plyometric training was found as an effective means for developing anaerobic power. A significant difference was also observed between the aqua-plyometric training with weighted vest group and land plyometric training group in anaerobic power. However, rest of the experimental groups didn't differ significantly. Aqua-plyometric training with weighted vest is a more effective training method than land plyometric training for improving the anaerobic power of the school athletes.

RESUMO O objetivo do presente estudo foi descobrir o efeito do treinamento pliométrico variado (treinamento pliométrico terrestre, treinamento aquapliométrico e treinamento aquapliométrico com colete ponderado) na potência anaeróbica de atletas escolares. Um total de quarenta e oito (n= 48) atletas escolares de nível distrital foram selecionados aleatoriamente. Todos os sujeitos foram divididos em quatro grupos iguais: i) grupo treinamento pliométrico terrestre (n=12), ii) grupo treinamento aquapliométrico (n=12), iii) grupo treinamento aquapliométrico com colete ponderado (n=12) e iv) grupo controle (n=12). O treino pliométrico variado foi intervencionado durante quatorze semanas nos respectivos grupos de treino. No presente estudo, a potência anaeróbia foi considerada como variável dependente e foi mensurada pelo teste de potência de Margaria-Kalamen. Para fazer inferências estatísticas sobre a potência anaeróbica entre os grupos nas condições pré e pós-intervenção, foi utilizada a ANCOVA, seguida do teste post-hoc de Tukey LSD. A significância das médias foi testada no nível 0,05. Diferentes grupos de treinamento pliométrico melhoraram significativamente em relação ao grupo controle na potência anaeróbica. Portanto, vários treinamentos pliométricos foram encontrados como um meio eficaz para o desenvolvimento da potência anaeróbica. Uma diferença significativa também foi observada entre o grupo de treinamento aquapliométrico com colete ponderado e o grupo de treinamento pliométrico terrestre na potência anaeróbica. No entanto, o resto dos grupos experimentais não diferiram significativamente. O treinamento aquapliométrico com colete ponderado é um método de treinamento mais eficaz do que o treinamento pliométrico terrestre para melhorar a potência anaeróbica dos atletas escolares.

Three weeks of a home-based "sleep low-train low" intervention improves functional threshold power in trained cyclists: A feasibility study.

BACKGROUND: "Sleep Low-Train Low" is a training-nutrition strategy intended to purposefully reduce muscle glycogen availability around specific exercise sessions, potentially amplifying the training stimulus via augmented cell signalling. The aim of this study was to assess the feasibility of a 3-week home-based "sleep low-train low" programme and its effects on cycling performance in trained athletes. METHODS: Fifty-five trained athletes (Functional Threshold Power [FTP]: 258 ± 52W) completed a home-based cycling training program consisting of evening high-intensity training (6 × 5 min at 105% FTP), followed by low-intensity training (1 hr at 75% FTP) the next morning, three times weekly for three consecutive weeks. Participant's daily carbohydrate (CHO) intake (6 g·kg-1·d-1) was matched but timed differently to manipulate CHO availability around exercise: no CHO consumption post- HIT until post-LIT sessions [Sleep Low (SL), n = 28] or CHO consumption evenly distributed throughout the day [Control (CON), n = 27]. Sessions were monitored remotely via power data uploaded to an online training platform, with performance tests conducted pre-, post-intervention. RESULTS: LIT exercise intensity reduced by 3% across week 1, 3 and 2% in week 2 (P < 0.01) with elevated RPE in SL vs. CON (P < 0.01). SL enhanced FTP by +5.5% vs. +1.2% in CON (P < 0.01). Comparable increases in 5-min peak power output (PPO) were observed between groups (P < 0.01) with +2.3% and +2.7% in SL and CON, respectively (P = 0.77). SL 1-min PPO was unchanged (+0.8%) whilst CON improved by +3.9% (P = 0.0144). CONCLUSION: Despite reduced relative training intensity, our data demonstrate short-term "sleep low-train low" intervention improves FTP compared with typically "normal" CHO availability during exercise. Importantly, training was completed unsupervised at home (during the COVID-19 pandemic), thus demonstrating the feasibility of completing a "sleep low-train low" protocol under non-laboratory conditions.

Moderate Intensity Exercise Training Improves Skeletal Muscle Performance in Symptomatic and Asymptomatic Statin Users.

BACKGROUND: The combination of statin therapy and physical activity reduces cardiovascular disease risk in patients with hyperlipidemia more than either treatment alone. However, mitochondrial dysfunction associated with statin treatment could attenuate training adaptations. OBJECTIVES: This study determined whether moderate intensity exercise training improved muscle and exercise performance, muscle mitochondrial function, and fiber capillarization in symptomatic and asymptomatic statin users. METHODS: Symptomatic (n = 16; age 64 ± 4 years) and asymptomatic statin users (n = 16; age 64 ± 4 years) and nonstatin using control subjects (n = 20; age 63 ± 5 years) completed a 12-week endurance and resistance exercise training program. Maximal exercise performance (peak oxygen consumption), muscle performance and muscle symptoms were determined before and after training. Muscle biopsies were collected to assess citrate synthase activity, adenosine triphosphate (ATP) production capacity, muscle fiber type distribution, fiber size, and capillarization. RESULTS: Type I muscle fibers were less prevalent in symptomatic statin users than control subjects at baseline (P = 0.06). Exercise training improved muscle strength (P < 0.001), resistance to fatigue (P = 0.01), and muscle fiber capillarization (P < 0.01), with no differences between groups. Exercise training improved citrate synthase activity in the total group (P < 0.01), with asymptomatic statin users showing less improvement than control subjects (P = 0.02). Peak oxygen consumption, ATP production capacity, fiber size, and muscle symptoms remained unchanged in all groups following training. Quality-of-life scores improved only in symptomatic statin users following exercise training (P < 0.01). CONCLUSIONS: A moderate intensity endurance and resistance exercise training program improves muscle performance, capillarization, and mitochondrial content in both asymptomatic and symptomatic statin users without exacerbating muscle complaints. Exercise training may even increase quality of life in symptomatic statin users. (The Effects of Cholesterol-Lowering Medication on Exercise Performance [STATEX]; NL5972/NTR6346).

Continuous Aerobic Training and High Intensity Interval Training Increase Exercise Tolerance in Heart Failure Patients: A Retrospective Study

Abstract Background: Conventional aerobic training is the first choice in cardiac rehabilitation for patients with chronic heart failure (CHF). However, high-intensity interval training (HIIT) may be an alternative, although it has little evidence. Objectives: To evaluate the effect of continuous aerobic training (CAT) or HIIT on exercise tolerance in CHF patients. Methods: Retrospective study with 30 patients, of both genders, members of a 10-week CAT or HIIT program. The control group (CON) consisted of patients who did not participate voluntarily in the program. Peak oxygen uptake (VO2peak), thresholds (LV1 and LV2), and ventilatory efficiency in the production of dioxide (VE/VCO2 slope), oxygen uptake efficiency (OUES), and VO2 recovery kinetics were analyzed. A two-way or repeated measures ANOVA was used, followed by Fisher's post-hoc test (p<0.05). Results: After 10 weeks of training, the CAT group increased the treadmill speed at LV1 (p=0.040), while the HIIT increased both the speed (p=0.030) and incline of the treadmill (p<0.001) for VO2peak and LV2, as well as the total time of the cardiopulmonary test. The VE/VCO2 slope was lower than that predicted for CAT (p=0.003) and HIIT (p=0.008). There was no change in VO2peak, recovery of heart rate (HR), and VO2, VE/VCO2, and OUES in both groups. Conclusions: After 10 weeks, both CAT and HIIT increased the tolerance to physical exercise. However, HIIT showed improvement in more parameters, differently from CAT.

Monitoring and adapting endurance training on the basis of heart rate variability monitored by wearable technologies: A systematic review with meta-analysis.

OBJECTIVES: To systematically perform a meta-analysis of the scientific literature to determine whether the outcomes of endurance training based on heart rate variability (HRV) are more favorable than those of predefined training. DESIGN: Systematic review and meta-analysis. METHODS: PubMed and Web of Science were searched systematically in March of 2020 using keywords related to endurance, the ANS, and training. To compare the outcomes of HRV-guided and predefined training, Hedges' g effect size and associated 95% confidence intervals were calculated. RESULTS: A total of 8 studies (198 participants) were identified comprising 9 interventions involving a variety of approaches. Compared to predefined training, most HRV-guided interventions included fewer moderate- and/or high-intensity training sessions. Fixed effects meta-analysis revealed a significant medium-sized positive effect of HRV-guided training on submaximal physiological parameters (g = 0.296, 95% CI 0.031 to 0.562, p = 0.028), but its effects on performance (g = 0.079, 95% CI -0.050 to 0.393, p = 0.597) and V̇O2peak (g = 0.171, 95% CI -0.213 to 0.371, p = 0.130) were small and not statistically significant. Moreover, with regards to performance, HRV-guided training was associated with fewer non-responders and more positive responders. CONCLUSIONS: In comparison to predefined training, HRV-guided endurance training had a medium-sized effect on submaximal physiological parameters, but only a small and non-significant influence on performance and V̇O2peak. There were fewer non-responders regarding performance with HRV-based training.

Continuous Protein Supplementation Reduces Acute Exercise-Induced Stress Markers in Athletes Performing Marathon.

The aim of this study was to determine the changes in endurance performance and metabolic, hormonal, and inflammatory markers induced by endurance stress (marathon race) in a combined strategy of training and dietary protein supplementation. The study was designed as a randomised controlled trial consisting of regular endurance training without and with a daily intake of a soy protein-based supplement over a three-month period in 2 × 15 (10 males and 5 females per group) endurance-trained adults. Body composition (body mass, BMI, and fat mass) was determined, and physical fitness was measured by treadmill ergometry at baseline and after 3 months of intervention; changes in exercise-induced stress and inflammatory markers (CK, myoglobin, interleukin-6, cortisol, and leukocytes) were also determined before and after a marathon competition; eating behaviour was documented before and after intervention by a three-day diet diary. Although no significant influence on endurance performance was observed, the protein supplementation regime reduced the exercise-induced muscle stress response. Furthermore, a protein intake of ≥20% of total energy intake led to a lower-level stress reaction after the marathon race. In conclusion, supplementary protein intake may influence exercise-induced muscle stress reactions by changing cellular metabolism and inflammatory pathways.

Four Weeks of 16/8 Time Restrictive Feeding in Endurance Trained Male Runners Decreases Fat Mass, without Affecting Exercise Performance.

BACKGROUND: Time restricted Feeding (TRF) is a dietary pattern utilized by endurance athletes, but there is insufficient data regarding its effects on performance and metabolism in this population. The purpose of this investigation was to examine the effects of a 16/8 TRF dietary pattern on exercise performance in trained male endurance runners. METHODS: A 4-week randomized crossover intervention was used to compare an 8-h TRF to a 12-h normal diet (ND) feeding window. Exercise training and dietary intake were similar across interventions. Runners completed a dual-energy X-ray absorptiometry (DXA) scan to assess body composition, a graded treadmill running test to assess substrate utilization, and ran a 10 km time trial to assess performance. RESULTS: There was a significant decrease in fat mass in the TRF intervention (-0.8 ± 1.3 kg with TRF (p = 0.05), vs. +0.1 ± 4.3 kg with ND), with no significant change in fat-free mass. Exercise carbon dioxide production (VCO2) and blood lactate concentration were significantly lower with the TRF intervention (p ≤ 0.02). No significant changes were seen in exercise respiratory exchange ratio or 10 km time trial performance (-00:20 ± 3:34 min:s TRF vs. -00:36 ± 2:57 min:s ND). CONCLUSION: This investigation demonstrated that adherence to a 4-week 16/8 TRF dietary intervention decreased fat mass and maintained fat-free mass, while not affecting running performance, in trained male endurance runners.

Effect of small vs large muscle mass endurance training on maximal oxygen uptake in organ transplanted recipients.

Maximal oxygen consumption (V̇O2max) is impaired in heart (HTx), kidney (KTx), and liver (LTx) transplanted recipients and the contribution of the cardiovascular, central, and peripheral (muscular) factors in affecting V̇O2max improvement after endurance training (ET) has never been quantified in these patients. ET protocols involving single leg cycling (SL) elicit larger improvements of the peripheral factors affecting O2 diffusion and utilization than the double leg (DL) cycling ET. Therefore, this study aimed to compare the effects of SL-ET vs DL-ET on V̇O2max. We determined the DL-V̇O2max and maximal cardiac output before and after 24 SL-ET vs DL-ET sessions on 33 patients (HTx = 13, KTx = 11 and LTx = 9). The DL-V̇O2max increased by 13.8% ± 8.7 (p < 0.001) following the SL-ET, due to a larger maximal O2 systemic extraction; meanwhile, V̇O2max in DL-ET increased by 18.6% ± 12.7 (p < 0.001) because of concomitant central and peripheral adaptations. We speculate that in transplanted recipients, SL-ET is as effective as DL-ET to improve V̇O2max and that the impaired peripheral O2 extraction and/or utilization play an important role in limiting V̇O2max in these types of patients. Novelty: SL-ET increases V̇O2max in transplanted recipients because of improved peripheral O2 extraction and/or utilization. SL-ET is as successful as DL-ET to improve the cardiorespiratory fitness in transplanted recipients. The model of V̇O2max limitation indicates the peripheral factors as a remarkable limitation to the V̇O2max in these patients.

Fractal correlation properties of heart rate variability as a biomarker of endurance exercise fatigue in ultramarathon runners.

Although heart rate variability (HRV) indexes have been helpful for monitoring the fatigued state while resting, little data indicate that there is comparable potential during exercise. Since an index of HRV based on fractal correlation properties, alpha 1 of detrended fluctuation analysis (DFA a1) displays overall organismic demands, alteration during exertion may provide insight into physiologic changes accompanying fatigue. Two weeks after collecting baseline demographic and gas exchange data, 11 experienced ultramarathon runners were divided into two groups. Seven runners performed a simulated ultramarathon for 6 h (Fatigue group, FG) and four runners performed daily activity over a similar period (Control group, CG). Before (Pre) and after (Post) the ultramarathon or daily activity, DFA a1, heart rate (HR), running economy (RE) and countermovement jumps (CMJ) were measured while running on a treadmill at 3 m/s. In Pre versus Post comparisons, data showed a decline with large effect size in DFA a1 post intervention only for FG (Pre: 0.71, Post: 0.32; d = 1.34), with minor differences and small effect sizes in HR (d = 0.02) and RE (d = 0.21). CG showed only minor differences with small effect sizes in DFA a1 (d = 0.19), HR (d = 0.15), and RE (d = 0.31). CMJ vertical peak force showed fatigue-induced decreases with large effect size in FG (d = 0.82) compared to CG (d = 0.02). At the completion of an ultramarathon, DFA a1 decreased with large effect size while running at low intensity compared to pre-race values. DFA a1 may offer an opportunity for real-time tracking of physiologic status in terms of monitoring for fatigue and possibly as an early warning signal of systemic perturbation.