-
Cyborg and Bionic Systems (Washington,... 2024The parameter setting of functional electrical stimulation (FES) is important for active recovery training since it affects muscle health. Among the FES parameters,...
The parameter setting of functional electrical stimulation (FES) is important for active recovery training since it affects muscle health. Among the FES parameters, current amplitude is the most influential factor. To explore the FES effect on the maximum stimulation time, this study establishes a curve between FES current amplitude and the maximum stimulation time based on muscle fatigue. We collect 10 subjects' surface electromyography under dumbbell weightlifting training and analyze the muscle fatigue state by calculating the root mean square (RMS) of power. By analyzing signal RMS, the fatigue characteristic curves under different fatigue levels are obtained. According to the muscle response under FES, the relationship curve between the current amplitude and the maximum stimulation time is established and FES parameters' effect on the maximum stimulation time is obtained. The linear curve provides a reference for FES parameter setting, which can help to set stimulation time safely, thus preventing the muscles from entering an excessive fatigue state and becoming more active to muscle recovery training.
PubMed: 38846791
DOI: 10.34133/cbsystems.0124 -
Frontiers in Sports and Active Living 2024In young adults, there is evidence that free arm movements do not help to compensate muscle fatigue-induced deteriorations in dynamic balance performance. However, the...
BACKGROUND
In young adults, there is evidence that free arm movements do not help to compensate muscle fatigue-induced deteriorations in dynamic balance performance. However, the postural control system in youth is immature, and as a result, the use of arm movements may provide a compensatory "upper body strategy" to correct fatigue-related balance impairments. Thus, the purpose of the present study was to compare the effects of free vs. restricted arm movement on dynamic balance performance prior and following exercise-induced muscle fatigue.
METHODS
Forty-three healthy youth (19 females; mean age: 12.8 ± 1.9 years) performed the Y Balance Test-Lower Quarter before and immediately after a fatiguing exercise (i.e., repetitive vertical bipedal box jumps until failure) using two different arm positions: free (move the arms freely) and restricted (keep the arms akimbo) arm movement.
RESULTS
Muscle fatigue ( ≤ 0.033; 0.10 ≤ ≤ 0.33) and restriction of arm movement ( ≤ 0.005; 0.17 ≤ ≤ 0.46) resulted in significantly deteriorated dynamic balance performance. However, the interactions between the two did not reach the level of significance ( ≥ 0.091; 0.01 ≤ ≤ 0.07).
CONCLUSION
Our findings indicate that the use of an "upper body strategy" (i.e., free arm position) has no compensatory effect on muscle fatigue-induced dynamic balance deteriorations in healthy youth.
PubMed: 38846020
DOI: 10.3389/fspor.2024.1391868 -
Journal of Cachexia, Sarcopenia and... Jun 2024An adequate magnesium intake might lower the risk of frailty through its role in muscle function.
BACKGROUND
An adequate magnesium intake might lower the risk of frailty through its role in muscle function.
METHODS
We analysed data from 81 524 women aged ≥60 years participating in the Nurses' Health Study. Total magnesium intake was obtained from repeated food frequency questionnaires administered between 1984 and 2010 and self-reported information on supplementation. Frailty was defined as having at least three of the following five FRAIL scale criteria: fatigue, low strength, reduced aerobic capacity, having ≥5 chronic illnesses and weight loss ≥ 5%. The occurrence of frailty was assessed every 4 years from 1992 to 2018. Cox proportional hazards models adjusted for lifestyle factors, medication use and dietary factors were used to assess the association between magnesium intake and frailty.
RESULTS
During a median follow-up of 16 years, we identified 15 477 incident cases of frailty. Women with a higher intake of total energy-adjusted magnesium had a decreased risk of frailty after adjustment for lifestyle factors, medication use and dietary factors. The relative risk (95% confidence interval) for Quintile 5 (Q5) versus Quintile 1 (Q1) was 0.88 (0.82, 0.94) (P-trend < 0.001). When only energy-adjusted magnesium from the diet was considered, the inverse association was stronger (Q5 vs. Q1: 0.68 [0.56, 0.82]; P-trend < 0.001). Those reaching the recommended daily allowance (RDA) of magnesium through diet had a 14% (9%, 19%) lower risk of frailty compared with those not meeting the RDA.
CONCLUSIONS
Increased intake of foods rich in magnesium was associated with a decreased risk of frailty.
PubMed: 38845194
DOI: 10.1002/jcsm.13450 -
Journal of Sports Science & Medicine Jun 2024Breast cancer survivors with obesity are at a high risk of cancer recurrence, comorbidity, and mortality. This review aims to systematically evaluate the effects of... (Meta-Analysis)
Meta-Analysis Review
Combined Aerobic and Resistance Training Improves Body Composition, Alters Cardiometabolic Risk, and Ameliorates Cancer-Related Indicators in Breast Cancer Patients and Survivors with Overweight/Obesity: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.
Breast cancer survivors with obesity are at a high risk of cancer recurrence, comorbidity, and mortality. This review aims to systematically evaluate the effects of combined aerobic and resistance training (CART) on body composition, lipid homeostasis, inflammation, adipokines, cancer-related fatigue, sleep, and quality of life in breast cancer patients and survivors with overweight/obesity. An electronic search was conducted in PubMed, Web of Science, Scopus, Science Direct, Cochrane, and Google Scholar databases from inception up to January 8, 2024. Randomized controlled trials (RCTs) meeting the inclusion criteria were selected for the analysis. The Cochrane risk of bias tool was used to assess eligible studies, and the GRADE method to evaluate the quality of evidence. A random-effects model was used, and data were analyzed using mean (MD) and standardized mean differences (SMD) for continuous variables with 95% confidence intervals (CI). We assessed the data for risk of bias, heterogeneity, sensitivity, reporting bias, and quality of evidence. A total of 17 randomized controlled trials were included in the systematic review involving 1,148 female patients and survivors (mean age: 54.0 ± 3.4 years). The primary outcomes showed significant improvements in body mass index (SMD -0.57 kg/m, = 0.04), body fat (SMD -0.50%, = 0.02), fat mass (SMD -0.63 kg, = 0.04), hip circumference (MD -3.14 cm, = 0.02), and fat-free mass (SMD 1.03 kg, < 0.001). The secondary outcomes indicated significant increases in high-density lipoprotein cholesterol (MD -0.05 mmol/L, = 0.008), natural killer cells (SMD 0.42%, = 0.04), reductions in triglycerides (MD -81.90 mg/dL, < 0.01), total cholesterol (SMD -0.95 mmol/L, < 0.01), tumor necrosis factor α (SMD -0.89 pg/mL, = 0.03), and leptin (SMD -0.63 ng/mL, = 0.03). Also, beneficial alterations were found in cancer-related fatigue (SMD -0.98, = 0.03), sleep (SMD -1.17, < 0.001), and quality of life (SMD 2.94, = 0.02) scores. There was very low to low confidence in the estimated effect of most of the outcomes. The present findings reveal that CART could be considered an adjunct therapy in supporting the conventional clinical approach observed following exercise. However, further high-quality research is needed to evaluate whether CART would be a valuable intervention to lower aggressive pharmacologic use in breast cancer patients with overweight/obesity.
Topics: Humans; Breast Neoplasms; Female; Resistance Training; Cancer Survivors; Randomized Controlled Trials as Topic; Body Composition; Obesity; Quality of Life; Cardiometabolic Risk Factors; Adipokines; Exercise; Fatigue; Sleep; Overweight
PubMed: 38841642
DOI: 10.52082/jssm.2024.366 -
Journal of Sports Science & Medicine Jun 2024In the recent past, practical blood flow restriction (pBFR) using non-pneumatic, usually elastic cuffs has been established as a cost-effective alternative to... (Randomized Controlled Trial)
Randomized Controlled Trial Comparative Study
Low-load Resistance Exercise with Perceptually Primed Practical Blood Flow Restriction Induces Similar Motor Performance Fatigue, Physiological Changes, and Perceptual Responses Compared to Traditional Blood Flow Restriction in Males and Females.
In the recent past, practical blood flow restriction (pBFR) using non-pneumatic, usually elastic cuffs has been established as a cost-effective alternative to traditional blood flow restriction (BFR) using pneumatic cuffs, especially for training in large groups. This study investigated whether low-load resistance exercise with perceptually primed pBFR using an elastic knee wrap is suitable to induce similar motor performance fatigue as well as physiological and perceptual responses compared to traditional BFR using a pneumatic nylon cuff in males and females. In a randomized, counterbalanced cross-over study, 30 healthy subjects performed 4 sets (30-15-15-15 repetitions) of unilateral knee extensions at 20% of their one-repetition-maximum. In the pBFR condition, each individual was perceptually primed to a BFR pressure corresponding to 60% of their arterial occlusion pressure. Before and after exercise, maximal voluntary torque, maximal muscle activity, and cuff pressure-induced discomfort were assessed. Moreover, physiological (i.e., muscle activity, muscle oxygenation) and perceptual responses (i.e., effort and exercise-induced leg muscle pain) were recorded during exercise. Moderate correlations with no differences between pBFR and BFR were found regarding the decline in maximal voluntary torque and maximal muscle activity. Furthermore, no to very strong correlations between conditions, with no differences, were observed for muscle activity, muscle oxygenation, and perceptual responses during exercise sets. However, cuff pressure-induced discomfort was lower in the pBFR compared to the BFR condition. These results indicate that low-load resistance exercise combined with perceptually primed pBFR is a convenient and less discomfort inducing alternative to traditional BFR. This is especially relevant for BFR training with people who have a low cuff-induced discomfort tolerance.
Topics: Humans; Female; Resistance Training; Male; Cross-Over Studies; Muscle Fatigue; Adult; Young Adult; Muscle, Skeletal; Regional Blood Flow; Torque; Myalgia; Perception; Oxygen Consumption; Blood Flow Restriction Therapy; Electromyography; Knee
PubMed: 38841639
DOI: 10.52082/jssm.2024.326 -
Journal of Sports Science & Medicine Jun 2024To determine how lateral shuffling/lateral shuffle (LS) -induced fatigue affects ankle proprioception and countermovement jump (CMJ) performance. Eighteen male college...
To determine how lateral shuffling/lateral shuffle (LS) -induced fatigue affects ankle proprioception and countermovement jump (CMJ) performance. Eighteen male college athletes performed 6 modes of a repeated LS protocol with 2 distances (2.5 and 5 m) and 3 speeds (1.6, 1.8, and 2.0 m/s). After LS, ankle inversion proprioception (AIP) was measured using the active movement extent discrimination apparatus (AMEDA). CMJ, blood lactate (BLa), heart rate (HR) and rating of perceived exertion (RPE) were measured before and after LS. The number of changes of direction (CODs) in each protocol was recorded. LS-induced fatigue was evident in BLa, HR and RPE (all p < 0.05), increasing with shorter shuffle distance and faster speed. RM-ANOVA showed a significant distance main effect on both AIP (p < 0.01) and CMJ (p < 0.05), but the speed main effect was only significant for CMJ (p ≤ 0.001), not AIP (p = 0.87). CMJ performance was correlated with BLa, HR and RPE (r values range from -0.62 to -0.32, all p ≤ 0.001). AIP was only correlated with CODs (r = -0.251, p < 0.01). These results suggested that in LS, shorter distance, regardless of speed, was associated with worse AIP, whereas subsequent CMJ performance was affected by both LS distance and speed. Hence, AIP performance was not related to physiological fatigue, but CMJ performance was. Results imply that LS affects processing proprioceptive input and producing muscular output differently, and that these two aspects of neuromuscular control are affected by physiological fatigue to varying degrees. These findings have implications for injury prevention and performance enhancement.
Topics: Humans; Male; Proprioception; Young Adult; Heart Rate; Muscle Fatigue; Ankle; Athletic Performance; Lactic Acid; Plyometric Exercise; Physical Exertion
PubMed: 38841636
DOI: 10.52082/jssm.2024.418 -
Journal of Sports Science & Medicine Jun 2024Non-local muscle fatigue (NLMF) refers to a transient decline in the functioning of a non-exercised muscle following the fatigue of a different muscle group. Most... (Randomized Controlled Trial)
Randomized Controlled Trial
Non-local muscle fatigue (NLMF) refers to a transient decline in the functioning of a non-exercised muscle following the fatigue of a different muscle group. Most studies examining NLMF conducted post-tests immediately after the fatiguing protocols, leaving the duration of these effects uncertain. The aim of this study was to investigate the duration of NLMF (1-, 3-, and 5-minutes). In this randomized crossover study, 17 recreationally trained participants (four females) were tested for the acute effects of unilateral knee extensor (KE) muscle fatigue on the contralateral homologous muscle strength, and activation. Each of the four sessions included testing at either 1-, 3-, or 5-minutes post-test, as well as a control condition for non-dominant KE peak force, instantaneous strength (force produced within the first 100-ms), and vastus lateralis and biceps femoris electromyography (EMG). The dominant KE fatigue intervention protocol involved two sets of 100-seconds maximal voluntary isometric contractions (MVIC) separated by 1-minute of rest. Non-dominant KE MVIC forces showed moderate and small magnitude reductions at 1-min (p < 0.0001, d = 0.72) and 3-min (p = 0.005, d = 0.30) post-test respectively. The KE MVIC instantaneous strength revealed large magnitude, significant reductions between 1-min (p = 0.021, d = 1.33), and 3-min (p = 0.041, d = 1.13) compared with the control. In addition, EMG data revealed large magnitude increases with the 1-minute versus control condition (p = 0.03, d = 1.10). In summary, impairments of the non-exercised leg were apparent up to 3-minutes post-exercise with no significant deficits at 5-minutes. Recovery duration plays a crucial role in the manifestation of NLMF.
Topics: Humans; Muscle Fatigue; Female; Cross-Over Studies; Electromyography; Male; Isometric Contraction; Muscle Strength; Young Adult; Knee; Time Factors; Adult; Quadriceps Muscle; Muscle, Skeletal; Hamstring Muscles
PubMed: 38841632
DOI: 10.52082/jssm.2024.425 -
Journal of Sports Science & Medicine Jun 2024Arm-cycling is a versatile exercise modality with applications in both athletic enhancement and rehabilitation, yet the influence of forearm orientation remains...
Arm-cycling is a versatile exercise modality with applications in both athletic enhancement and rehabilitation, yet the influence of forearm orientation remains understudied. Thus, this study aimed to investigate the impact of forearm position on upper-body arm-cycling Wingate tests. Fourteen adult males (27.3 ± 5.8 years) underwent bilateral assessments of handgrip strength in standing and seated positions, followed by pronated and supinated forward arm-cycling Wingate tests. Electromyography (EMG) was recorded from five upper-extremity muscles, including anterior deltoid, triceps brachii lateral head, biceps brachii, latissimus dorsi, and brachioradialis. Simultaneously, bilateral normal and propulsion forces were measured at the pedal-crank interface. Rate of perceived exertion (RPE), power output, and fatigue index were recorded post-test. The results showed that a pronated forearm position provided significantly (p < 0.05) higher normal and propulsion forces and triceps brachii muscle activation patterns during arm-cycling. No significant difference in RPE was observed between forearm positions (p = 0.17). A positive correlation was found between seated handgrip strength and peak power output during the Wingate test while pronated (dominant: p = 0.01, r = 0.55; non-dominant: p = 0.03, r = 0.49) and supinated (dominant: p = 0.03, r = 0.51; don-dominant: p = 0.04, r = 0.47). Fatigue changed the force and EMG profile during the Wingate test. In conclusion, this study enhances our understanding of forearm position's impact on upper-body Wingate tests. These findings have implications for optimizing training and performance strategies in individuals using arm-cycling for athletic enhancement and rehabilitation.
Topics: Humans; Male; Electromyography; Forearm; Hand Strength; Adult; Muscle, Skeletal; Young Adult; Biomechanical Phenomena; Pronation; Exercise Test; Supination; Muscle Fatigue; Physical Exertion; Arm; Upper Extremity
PubMed: 38841629
DOI: 10.52082/jssm.2024.396 -
BMC Neurology Jun 2024Myasthenia gravis (MG) is a long-term autoimmune disorder that affects the neuromuscular junction, causing muscle weakness and fatigue as its primary clinical features....
BACKGROUND
Myasthenia gravis (MG) is a long-term autoimmune disorder that affects the neuromuscular junction, causing muscle weakness and fatigue as its primary clinical features. Vitamin D is crucial for both the autoimmune response and skeletal muscle function.
CASE PRESENTATION
Here, we presented a case report documenting the substantial improvement in symptoms experienced by a patient who underwent subtotal gastrectomy for gastric cancer following high-dose Vitamin D supplementation. The patient developed generalized MG two months after the surgery and did not respond adequately to pyridostigmine therapy, experiencing a progressive deterioration of the condition. A significant reduction in vitamin D concentration was observed following subtotal gastrectomy. In response, high-dose vitamin D supplementation was administered to the patient. Within one week of treatment, swallowing symptoms improved, enabling the consumption of a small amount of liquid food. By the second week, substantial swallowing and neck function improvements were evident. After one month, the patient regained the ability to straighten the neck while walking and consumed a regular diet despite persistent difficulties chewing hard food.
CONCLUSIONS
This case underscores the therapeutic potential of vitamin D in alleviating MG symptoms, particularly in individuals with compromised vitamin D levels following gastrectomy. The observed improvements present a new perspective on the possible involvement of vitamin D supplementation in the management of postoperative MG cases.
Topics: Humans; Gastrectomy; Myasthenia Gravis; Vitamin D; Stomach Neoplasms; Male; Female; Aged; Middle Aged; Dietary Supplements
PubMed: 38840065
DOI: 10.1186/s12883-024-03687-z