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Frontiers in Sports and Active Living 2024Previous research has demonstrated that stretching can enhance athletic performance and induce cardiovascular adaptations. This study aims to assess whether a 4-week...
Previous research has demonstrated that stretching can enhance athletic performance and induce cardiovascular adaptations. This study aims to assess whether a 4-week preventative stretching routine can enhance heart rate variability and heart rate recovery, faster blood lactate clearance, and improve performance following submaximal strength exercises. Twenty-four healthy adults were recruited and randomly allocated to either the experimental group or the control group. Both groups engaged in submaximal strength exercises (5 sets to voluntary failure at 60% of 1RM) comprising bench press and back squat exercises under baseline conditions and after stretching protocol. The experimental group followed the Stretching Protocol, while the control group adhered to their regular training routine. ANOVA analysis revealed a significant pre-post interaction effect between groups in the variable of squat repetitions, although no notable pre- or post-differences were observed in heart rate variability, heart rate recovery, blood lactate concentration, or bench repetitions in either group. A 4-week preventative stretching program does not appear adequate to enhance lactate clearance and cardiovascular adaptation after submaximal strength exercises in resistance-trained individuals compared to the control group. However, it is plausible that such a stretching routine may mitigate muscle fatigue, though further investigation is warranted to substantiate this hypothesis.
PubMed: 38957877
DOI: 10.3389/fspor.2024.1424756 -
TheScientificWorldJournal 2024The medicinal plant . is used to treat cardiovascular disease, chronic fatigue, low libido, as well as increased diuresis. However, studies considering the toxicity of...
The medicinal plant . is used to treat cardiovascular disease, chronic fatigue, low libido, as well as increased diuresis. However, studies considering the toxicity of this plant are scarce. Develop an aqueous extract of considering traditional use and determine the average lethality (LD), signs, and symptoms of toxicity. The extract was obtained by immersing the root bark in ultrapure water for 18 hours at 4°C, under constant stirring. The test extract was administered in a single dose of 2.000 mg/kg by gavage to rats. Signs and symptoms of toxicity were determined according to the Hippocratic screening test and compared with the control group. In addition, a necropsy was performed for macroscopic evaluation of the organs in the abdominal cavity. A powder was obtained from aqueous extracts that showed the same organoleptic characteristics and emulsification capacity as those presented by the fresh root when prepared according to popular tradition. The LD was greater than the test dose with three animals surviving. On the other hand, necropsy of dead rats showed necrosis and reduction in lung mass, in addition to the presence of foam and excessive distension of the stomach and intestines. The main symptoms of toxicity were anesthesia, ataxia, sedation, loss of muscle strength, and excessive drowsiness in the first 24 hours. There was no difference between the control and extract groups with regard to body mass, food, and water intake, as well as in macroscopy of the heart, liver, lungs, intestines, spleen, pancreas, and kidneys. The aqueous extract of the was considered nontoxic or of very low toxicity. However, it is capable of altering the activity of the central nervous system and causing disorders in the respiratory and digestive systems.
Topics: Animals; Plant Extracts; Rats; Plant Bark; Male; Plant Roots; Lethal Dose 50; Female; Toxicity Tests, Acute; Rats, Wistar; Models, Animal
PubMed: 38957454
DOI: 10.1155/2024/8991384 -
European Journal of Sport Science Jul 2024To investigate the effects of 8-week hiking bench training on cardiorespiratory and muscular responses of highly trained sailors during hiking emulation. Twenty-four...
To investigate the effects of 8-week hiking bench training on cardiorespiratory and muscular responses of highly trained sailors during hiking emulation. Twenty-four sailors were assigned into two groups: the hiking bench training group (HTG, n = 12) and the control group (CG, n = 12). Both groups maintained their regular training with the HTG performed two additional hiking bench training sessions per week for 8 weeks, while the CG performed an equivalent duration of on-water sailing training. Physiological responses were assessed by performing four successive 3-min hiking bouts on a sailing emulation ergometer before and after the 8-week training period. Comparing the pretest, both groups exhibited a significant decrease (p < 0.05) in the percentage of maximal oxygen uptake (%VOmax) and maximal heart rate (%HRmax); the HTG experienced a greater decrease in %VOmax in bouts 2 and 3. The root mean square (RMS) of rectus femoris (RF), vastus lateralis (VL), rectus abdominis (RA), and external oblique decreased significantly (p < 0.05), whereas the mean power frequency (MPF) of RF, VL, and RA exhibited an increasing trend. The RMS of RF and RA in HTG were lower than those in CG in the initial three bouts; VL and EA in HTG were lower than those in CG in bouts 1 and 2 (p < 0.05). The MPF of RA in HTG was significantly increased in bouts 2, 3, and 4 (p < 0.05). Eight-week hiking bench training could improve hiking economy and the activation of lower limb and trunk muscles delaying the onset of fatigue in sailors.
Topics: Humans; Water Sports; Oxygen Consumption; Heart Rate; Male; Young Adult; Ships; Adult; Physical Conditioning, Human; Muscle, Skeletal; Cardiorespiratory Fitness; Quadriceps Muscle
PubMed: 38956795
DOI: 10.1002/ejsc.12118 -
European Journal of Sport Science Jul 2024The prolonged consequences of SARS-CoV-2 on young elite athletes recovering from primary and reinfection are unclear. This study aimed to assess inspiratory/expiratory...
A follow-up study on respiratory outcomes, quality of life and performance perception of SARS-CoV-2 primary and reinfection in elite athletes: A 9-month prospective study.
The prolonged consequences of SARS-CoV-2 on young elite athletes recovering from primary and reinfection are unclear. This study aimed to assess inspiratory/expiratory muscle strength and respiratory function at the time of spontaneous recovery at 3, 6, and 9 months after SARS-CoV-2 primary and reinfection in elite athletes. The study enrolled 25 elite male judoists, including 11 primary infection cases, five reinfection cases, and nine controls from the Türkiye Olympic Preparation Center. Inspiratory/expiratory muscle strength and respiratory function were measured, including maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), forced expiratory volume in 1 s (FEV), forced vital capacity (FVC), FEV/FVC, and peak expiratory flow (PEF) before and up to 9 months after SARS-CoV-2 infection in the early pre-competition preparation phases. The most common symptoms reported by reinfection cases were fatigue (80%), dyspnea (60%), and muscle/joint pain (60%), while primary infection cases reported fatigue (73%), muscle/joint pain (45%), and headache (45%). MIP decreased by -14% and MEP decreased by -13% following the SARS-CoV-2 infection in reinfection cases. Likewise, FEV and FVC decreased by -5% and -8%, respectively; consequently, FEV/FVC increased by 3%. Inspiratory/expiratory muscle strength and respiratory function improved rapidly after 9 months of SARS-CoV-2 infection in primary cases, whereas dysfunction persisted in reinfection cases. PEF was unaffected throughout the 9-month follow-up period. Reinfection may lead to further alterations in respiratory system relative to the primary infection, with a suspected restrictive pattern that remains dysfunctional in the third month; however, it improves significantly during a 9-month follow-up period.
Topics: Humans; COVID-19; Male; Prospective Studies; Follow-Up Studies; Muscle Strength; Young Adult; Quality of Life; Respiratory Muscles; Athletes; Athletic Performance; Reinfection; SARS-CoV-2; Respiratory Function Tests; Fatigue; Dyspnea; Adolescent; Vital Capacity; Headache; Forced Expiratory Volume
PubMed: 38956787
DOI: 10.1002/ejsc.12109 -
Scientific Reports Jul 2024Plyometric training is characterized by high-intensity exercise which is performed in short term efforts divided into sets. The purpose of the present study was twofold:... (Randomized Controlled Trial)
Randomized Controlled Trial
Plyometric training is characterized by high-intensity exercise which is performed in short term efforts divided into sets. The purpose of the present study was twofold: first, to investigate the effects of three distinct plyometric exercise protocols, each with varying work-to-rest ratios, on muscle fatigue and recovery using an incline-plane training machine; and second, to assess the relationship between changes in lower limb muscle strength and power and the biochemical response to the three exercise variants employed. Forty-five adult males were randomly divided into 3 groups (n = 15) performing an exercise of 60 rebounds on an incline-plane training machine. The G0 group performed continuous exercise, while the G45 and G90 groups completed 4 sets of 15 repetitions, each set lasting 45 s with 45 s rest in G45 (work-to-rest ratio of 1:1) and 90 s rest in G90 (1:2 ratio). Changes in muscle torques of knee extensors and flexors, as well as blood lactate (LA) and ammonia levels, were assessed before and every 5 min for 30 min after completing the workout. The results showed significantly higher (p < 0.001) average power across all jumps generated during intermittent compared to continuous exercise. The greatest decrease in knee extensor strength immediately post-exercise was recorded in group G0 and the least in G90. The post-exercise time course of LA changes followed a similar pattern in all groups, while the longer the interval between sets, the faster LA returned to baseline. Intermittent exercise had a more favourable effect on muscle energy metabolism and recovery than continuous exercise, and the work-to-rest ratio of 1:2 in plyometric exercises was sufficient rest time to allow the continuation of exercise in subsequent sets at similar intensity.
Topics: Humans; Male; Rest; Muscle Fatigue; Adult; Muscle Strength; Plyometric Exercise; Young Adult; Muscle, Skeletal; Lactic Acid; Ammonia; Exercise
PubMed: 38956280
DOI: 10.1038/s41598-024-66146-2 -
International Immunopharmacology Jul 2024To study the cross-border regulation of immunity and energy metabolism by ginseng miRNA156, and to provide a new perspective for further exploring the possibility of...
AIM OF THE STUDY
To study the cross-border regulation of immunity and energy metabolism by ginseng miRNA156, and to provide a new perspective for further exploring the possibility of ginseng miRNA156 as a pharmacodynamic substance.
MATERIALS AND METHODS
Combined with the previous research results of our research group, miRNA156 with high expression in blood sequencing of intragastrically administered with ginseng decoction was selected. Bioinformatics analysis was performed on the selected differential miRNA156. The target genes of differential miRNA156 were mainly enriched in metabolic, immune and other signaling pathways. According to the analysis results, the experimental part will use qi deficiency fatigue model and RAW264.7 cells. The contents of lactic acid (LA), creatine kinase (CK), blood urea nitrogen (BUN), lactate dehydrogenase (LD), liver glycogen (LG), muscle glycogen (MG), interleukin 4 (IL-4), matrix metallo-proteinase 9 (MMP-9), superoxide dismutase (SOD), malondialdehyde, phosphor-enolpyruvate carboxykinase (PEPCK), glucose-6-phosphatase (G6pase), nitric oxide (NO) and tumor necrosis factor-α (TNF-α) were measured after administration of miRNA156.
RESULTS
Ginseng miRNA156 can accelerate the removal of metabolic waste during exercise. Increase the glycogen reserve in, provide energy for the body, regulate the activity of key gluconeogenesis enzyme phosphorus, improve the energy metabolism system of, and enhance the endurance of fatigue mice. The contents of matrix metalloproteinase 9, superoxide dismutase and malondialdehyde were affected, and the content of TNF-α in the supernatant of RAW264.7 cells was significantly increased, which had certain antioxidant capacity and potential immunomodulatory effects.
CONCLUSION
Ginseng miRNA156 has a certain regulatory effect on the energy metabolism and immune function of mice, which makes it possible to regulate the cross-species regulation of ginseng miRNA in theory, provides ideas for ginseng miRNA to become a new pharmacodynamic substance.
PubMed: 38955029
DOI: 10.1016/j.intimp.2024.112577 -
European Journal of Applied Physiology Jul 2024Eccentric quasi-isometric (EQI) resistance training is emerging as a promising option in sports medicine and rehabilitation. Despite prior research on EQI contractions...
PURPOSE
Eccentric quasi-isometric (EQI) resistance training is emerging as a promising option in sports medicine and rehabilitation. Despite prior research on EQI contractions in quadriceps and biceps brachii, their use in hamstring injury contexts is underexplored. Therefore, our study examines and contrasts the biomechanics and fatigue effects of EQI training on knee extensors and flexors.
METHODS
Following familiarization, 16 healthy, active participants (9 men, 7 women; 23.5 ± 2.6 years, 72.1 ± 12.8 kg, 173.4 ± 10.7 cm) performed, in random order, four EQI contractions for knee extensions and flexions, respectively. EQI contractions were isotonically loaded to 70% of concentric (60°·s) maximal voluntary contraction. Rest between repetitions was set at three minutes, while four minutes separated each muscle group. Peak torque, mean torque, and optimal angle were evaluated pre- and post-bouts. Inter-repetition contraction time and angular velocity were also assessed.
RESULTS
Average torque was 160.9 ± 44.2 and 71.5 ± 23.2 Nm for the extensors and flexors. Peak and mean torque significantly decreased for both extensors (p < 0.001, d = 0.70-0.71) and flexors (p ≤ 0.022, d = 0.36) after EQI contractions, respectively. However, the optimal angle increased for extensors (p < 0.001, d = 1.00) but not flexors (p = 0.811, d = 0.06). During EQI contractions, knee flexors exhibited greater intra-repetition velocity than extensors (p = 0.002; η = 0.50). Decreases in inter-repetition time and range of motion were more consistent for the extensors.
CONCLUSIONS
Distinct responses exist when comparing EQI contractions of the knee extensors and flexors, particularly their effect on peak torque angles. These findings suggest knee flexors may require lower relative intensities to align more closely with extensor EQI contractions.
PubMed: 38953975
DOI: 10.1007/s00421-024-05544-w -
Muscle & Nerve Jul 2024Fatigue is a common and debilitating symptom encountered in the neuromuscular clinic. The 7-item Fatigue Severity Scale (FSS-7) is a Rasch-modified assessment validated...
INTRODUCTION/AIMS
Fatigue is a common and debilitating symptom encountered in the neuromuscular clinic. The 7-item Fatigue Severity Scale (FSS-7) is a Rasch-modified assessment validated in inflammatory neuropathies but not across a typical neuromuscular patient population. The aim of this study was to validate this measure in neuromuscular disorders and to compare between patient sex, age and diagnoses.
METHODS
The modified FSS-7 was mailed to patients recruited from a specialist neuromuscular clinic at the Walton Centre. Responses were subjected to Rasch analysis and descriptive statistics were performed on the Rasch converted data.
RESULTS
The mFSS-7 met the Rasch model expectations with an overall Chi-square probability of 0.4918, a strict unidimensional scale free from differential item functioning (DIF) that satisfied the model with substantial test-retest reliability using Lin's concordance correlation coefficient 0.71 (95% CI 0.63-0.77). A 15.7% ceiling effect was observed in this patient cohort. Post hoc analysis did not show any significant difference in fatigue between sex, age or neuromuscular diagnoses.
DISCUSSION
The self-completed Rasch mFSS-7 showed acceptable test-retest reliability across patients with varied disorders under follow-up in a specialist neuromuscular clinic. The ceiling effect constrains its use for those with the most severe fatigue. Future considerations could include assessment of the benefits of clinical interventions, particularly multidisciplinary team input or dedicated fatigue clinics.
PubMed: 38953614
DOI: 10.1002/mus.28186 -
Journal of Physical Therapy Science Jul 2024[Purpose] This study examined the effects of expiratory muscle training on fatigue in individual respiratory muscles. [Participants and Methods] Healthy adult males...
[Purpose] This study examined the effects of expiratory muscle training on fatigue in individual respiratory muscles. [Participants and Methods] Healthy adult males (n=31) were randomly assigned to two groups: expiratory muscle training (n=15) and normal controls (n=16). In the expiratory muscle training group, training was performed once for 15 min at 50% load of the maximum expiratory mouth pressure twice daily for 4 weeks. Respiratory muscle fatigue indicators were measured using surface electromyography as the median power frequency of each respiratory muscle at the time of measuring the maximum inspiratory mouth pressure during 20 min of inspiratory muscle loading and maximum expiratory mouth pressure. [Results] In the expiratory muscle training group, the median power frequency values of the sternocleidomastoid, rectus abdominis, and internal oblique/external oblique before expiratory muscle training significantly decreased during inspiratory muscle loading. However, no difference was observed in the median power frequency values measured before and during inspiratory muscle loading after the expiratory muscle training. In the normal controls, the median power frequency values of the sternocleidomastoid and rectus abdominis significantly decreased during inspiratory muscle loading. [Conclusion] Expiratory muscle training increased fatigue tolerance of the sternocleidomastoid, rectus abdominis, and internal and external oblique muscles in healthy individuals.
PubMed: 38952458
DOI: 10.1589/jpts.36.382 -
European Journal of Applied Physiology Jun 2024This study examined the effect of acute acetaminophen (ACTP) ingestion on physical performance during the 5 m shuttle run test (5mSRT), attention, mood states, and the...
Acute ingestion of acetaminophen improves cognitive and repeated high intensity short-term maximal performance in well-trained female athletes: a randomized placebo-controlled trial.
This study examined the effect of acute acetaminophen (ACTP) ingestion on physical performance during the 5 m shuttle run test (5mSRT), attention, mood states, and the perception of perceived exertion (RPE), pain (PP), recovery (PRS), and delayed onset of muscle soreness (DOMS) in well-trained female athletes. In a randomized, placebo-controlled, double-blind, crossover trial, fifteen well-trained female athletes (age 21 ± 2 years, height 165 ± 6 cm, body mass 62 ± 5 kg) swallowed either 1.5 g of ACTP or 1.5 g of placebo. The profile of mood states (POMS) and digit cancellation (DCT) were assessed 45 min postingestion, and 5mSRT was performed 60 min postingestion. The RPE and PP were determined immediately after each 30-s repetition of the 5mSRT, and the PRS and DOMS were recorded at 5 min and 24 h post-5mSRT. For the 5mSRT, ACTP ingestion improved the greatest distance (+ 10.88%, p < 0.001), total distance (+ 11.33%, p = 0.0007) and fatigue index (+ 21.43%, p = 0.0003) compared to PLA. Likewise, the DCT score was better on the ACTP (p = 0.0007) than on the PLA. RPE, PP, PRS, and DOMS scores were improved after ACTP ingestion (p < 0.01 for all comparisons) compared to PLA. POMS scores were enhanced with ACTP ingestion compared to PLA (p < 0.01). In conclusion, this study indicates that acute acetaminophen ingestion can improve repeated high intensity short-term maximal performance, attention, mood states, and perceptions of exertion, pain, recovery, and muscle soreness in well-trained female athletes, suggesting potential benefits for their overall athletic performance and mood state.
PubMed: 38951182
DOI: 10.1007/s00421-024-05534-y