Sex differences in strength, functional capacity and mobility in patients with multiple sclerosis: An exploratory analysis.

BACKGROUND: Physical exercise programs are commonly designed without consideration for sex differences. Nevertheless, disease progression exhibits sex-specific patterns, resulting in different functionality and strength performances. OBJECTIVES: To analyze sex differences in strength, functional capacity, and mobility, and to evaluate sex-dependent differences in leg strength in multiple sclerosis (MS) patients. METHODS: A cross-sectional study was conducted with 35 participants (female: n = 19; Expanded Disability Status Scale (EDSS)= 3.0 ± 1.2, male: n = 16; EDSS= 3.3 ± 1.2). Body composition, maximal voluntary isometric contraction (MVIC), explosive strength (rate of force development, RFD), central activation ratio (CAR), functional capacity, and mobility were assessed. RESULTS: Differences were observed between males and females (p = 0.001) in height, lean body mass and MVIC. No differences were observed in the other variables. Regarding the leg asymmetry, men showed higher values in the stronger leg for both MVIC (p < 0.001, d=large) and RFD, whereas women showed higher values only in RFD. Men with MS demonstrated a greater capacity to produce maximal strength than women with this disease. CONCLUSIONS: The results found suggest that maximum strength differs between men and women in our sample of patients with multiple sclerosis. Furthermore, the weaker leg, regardless of sex, exhibits poorer results in explosive strength compared to the stronger leg. However, maximum strength only shows differences in men and not in women. Therefore, these findings should serve as a basis for rehabilitation professionals when planning training programs for this population.

Exploring factors of adherence to weight loss interventions in population with overweight/obesity: an umbrella review.

Adherence is key for achieving the optimal benefits from a weight loss intervention. Despite the number of studies on factors that promote adherence, their findings suggest inconsistent and fragmented evidence. The aim of this study was to review the existing factors of adherence to weight loss interventions and to find factors that facilitate the design of effective intervention programs. Six databases were searched for this umbrella review; after the screening process, 21 studies were included. A total of 47 factors were identified in six groups as relevant for adherence: (i) sociodemographic (n = 7), (ii) physical activity (n = 2), (iii) dietary (n = 8), (iv) behavioral (n = 4), (v) pharmacological (n = 3), and (vi) multi-intervention (n = 23). In addition, a map of adherence factors was created. The main findings are that with respect to demographic factors, the development of personalized intervention strategies based on the characteristics of specific populations is encouraged. Moreover, self-monitoring has been shown to be effective in behavioral, dietary, and multi-interventions, while technology has shown potential in dietary, behavioral, and multi-interventions. In addition, multi-interventions are adherence-promoting strategies, although more evidence is required on adherence to pharmacological interventions. Overall, the factor map can be controlled and modified by researchers and practitioners to improve adherence to weight loss interventions.

Efficacy of Split Versus Full-Body Resistance Training on Strength and Muscle Growth: A Systematic Review With Meta-Analysis.

ABSTRACT: Ramos-Campo, DJ, Benito-Peinado, PJ, Caravaca, LA, Rojo-Tirado, MA, and Rubio-Arias, JÁ. Efficacy of split versus full-body resistance training on strength and muscle growth: a systematic review with meta-analysis. J Strength Cond Res 38(7): 1330-1340, 2024-No previous study has systematically compared the effect of 2 resistance training routines commonly used to increase muscle mass and strength (i.e., split [Sp] and full-body [FB] routines). Our objective was to conduct a systematic review and meta-analysis following PRISMA guidelines to compare the effects on strength gains and muscle growth in healthy adults. 14 studies (392 subjects) that compared Sp and FB routines in terms of strength adaptations and muscle growth were included. Regarding the effects of the Sp or FB routine on both bench press and lower limbs strength, the magnitude of the change produced by both routines was similar (bench press: mean difference [MD] = 1.19; [-1.28, 3.65]; p = 0.34; k = 14; lower limb: MD = 2.47; [-2.11, 7.05]; p = 0.29; k = 14). Concerning the effect of the Sp vs. FB routine on muscle growth, similar effects were observed after both routines in the cross-sectional area of the elbow extensors (MD = 0.30; [-2.65, 3.24]; p = 0.84; k = 4), elbow flexors (MD = 0.17; [-2.54, 2.88]; p = 0.91; k = 5), vastus lateralis (MD = -0.08; [-1.82, 1.66]; p = 0.93; k = 5), or lean body mass (MD = -0.07; [-1.59, 1.44]; p = 0.92; k = 6). In conclusion, the present systematic review and meta-analysis provides solid evidence that the use of Sp or FB routines within a resistance training program does not significantly impact either strength gains or muscle hypertrophy when volume is equated. Consequently, individuals are free to confidently select a resistance training routine based on their personal preferences.

Exercise influence on monocarboxylate transporter 1 (MCT1) and 4 (MCT4) in the skeletal muscle: A systematic review.

This review aims to systematically analyze the effect of exercise on muscle MCT protein levels and mRNA expression of their respective genes, considering exercise intensity, and duration (single-exercise session and training program) in humans and rodents, to observe whether both models offer aligned results. The review also aims to report methodological aspects that need to be improved in future studies. A systematic search was conducted in the PubMed and Web of Science databases, and the Preferred Reporting Items for Systematic review and Meta-Analyses (PRISMA) checklist was followed. After applying inclusion and exclusion criteria, 41 studies were included and evaluated using the Cochrane collaboration tool for risk of bias assessment. The main findings indicate that exercise is a powerful stimulus to increase MCT1 protein content in human muscle. MCT4 protein level increases can also be observed after a training program, although its responsiveness is lower compared to MCT1. Both transporters seem to change independently of exercise intensity, but the responses that occur with each intensity and each duration need to be better defined. The effect of exercise on muscle mRNA results is less defined, and more research is needed especially in humans. Moreover, results in rodents only agree with human results on the effect of a training program on MCT1 protein levels, indicating increases in both. Finally, we addressed important and feasible methodological aspects to improve the design of future studies.

Response to physical activity of females with multiple sclerosis throughout the menstrual cycle: a protocol for a randomised crossover trial (EMMA Project).

The relationship between multiple sclerosis (MS) and females is a crucial aspect in the development of the disease, with the ovarian hormonal cycle being a sensitive stage, especially in females with relapsing-remitting multiple sclerosis. The objectives of the study are to identify moderating variables that modify satisfaction with physical activity practice throughout the menstrual cycle (MC) in females in or out of their MC, during high-intensity interval training (HIIT) and strength training sessions and to compare the acute effects of different types of physical activity sessions in females with and without MS. This protocol is the methodology used in the EMMA Study, a randomised, single-blind crossover trial study conducted in females with MS who were matched 1:1, based on age, lifestyle factors and country of residence, with females without MS, to analyse the effect of physical activity practice on satisfaction, functionality, fatigue and inflammatory profile through their MC. Participants will visit the facilities approximately 10 times (4 preliminary familiarisation visits and 6 visits to carry out a physical activity session in each phase of the MC) for 3-4 months. A total sample of 30 females (15 females without MS and 15 with MS) is necessary for the study. The evaluation will comprise clinical, nutritional and psychological interviews, including different variables. It is hypothesised during the luteal phase, females with MS are expected to exhibit different acute responses to HIIT and strength training sessions as compared with females without the disease. Before starting the study, all participants will read and sign an informed consent form. Trial registration number: This research protocol is registered with ClinicalTrials.gov to ensure transparency and accessibility of study information (NCT06105463). The university's ethics committee number for this study is UALBIO2022/048.

The ergogenic effects of acute carbohydrate feeding on endurance performance: a systematic review, meta-analysis and meta-regression.

A systematic review with meta-analysis was conducted to analyze the effect of carbohydrate (CHO) intake during exercise and some variables that could moderate this effect on endurance performance. We included 136 studies examining the effect of CHO ingestion during endurance exercise in the meta-analysis. The overall effect on performance showed a significant increase after CHO intake compared to the placebo/control groups. A larger effect of CHO consumption is observed in time to exhaustion than in time trials performance test. Moreover, the effectiveness of CHO supplementation was greater the longer the duration of the events. Also, there seems to be a higher effect of CHO intake in lower trained than in higher trained participants. In contrast, the magnitude of performance change of CHO intake is not affected by the dosage, ergometer used, the type of intake of the CHO ingestion and the type of CHO. In addition, a lower rate of perceived exertion and higher power and heart rate are significantly associated with the ingestion of CHO during endurance exercise. These results reinforce that acute CHO feeding is an effective strategy for improving endurance performance, especially, in less trained subjects participating in time to exhaustion tests of longer durations.

Lateral wedge insoles and their use in ankle instability.

The aim of the present study is to assess the immediate effects of applying lateral wedge insoles of different heights (0.00, 0.3, 0.4, and 0.6 cm) in patients with chronic ankle instability (CAI) in normal and supinated feet during a Star Excursion Balance Test (SEBT) and in the reflex response of Peroneus Longus (PL), Peroneus Brevis (PB), and Tibialis Anterior (TA) over a 30° inversion of the feet. The effects of the height of the wedges were assessed using a double-blind, crossover design. In total, 25 participants were allocated into two groups, depending on the foot posture (Normal = 12, Supinated = 13) and performed the tests in a random fashion. Reaction time (RT) of stabilizing muscles of the ankle was measured using superficial electromyography (EMG) and postural balance with the SEBT. Foot posture did not show any significant effects on the analyzed variables. Nonetheless, the use of a 0.3 cm external rearfoot wedge (PB p = 0.002; PL p = 0.066 and TA p = 0.006) and 0.6 cm (PB p = 0.043; PL p = 0.058 and TA p = 0.071) reduces RT in stabilizing muscles of the ankle and improves results in SEBT, except for the anterolateral direction, in subjects with CAI. Therefore, our results suggest that the use of lateral wedge insoles could reduce RT and improve dynamic balance in chronic ankle instability.

Effects and optimal dosage of resistance training on strength, functional capacity, balance, general health perception, and fatigue in people with multiple sclerosis: a systematic review and meta-analysis.

PURPOSE: To analyze the effectiveness of resistance training programs (RTP) on strength, functional capacity, balance, general health perception, and fatigue for people with Multiple Sclerosis (MS) and to determine the most effective dose of RTP in this population. METHODS: Studies examining the effect of RTP on strength, functional capacity, balance, general health perception, and fatigue in MS patients were included. 44 studies were included. The meta-analysis, subgroup analysis and meta-regression methods were used to calculate the mean difference and standardized mean difference. RESULTS: Significant group differences were observed in knee extensor (p = 0.01) and flexor (p < 0.001), but not in 1-repetition maximum. Regarding functional capacity and balance, differences between groups, in favour of the RTP group, were found in the Timed Up and Go Test (p = 0.001), walking endurance, (p = 0.02) gait speed (p = 0.02) and balance (p = 0.02). No significant differences between groups were observed in fatigue or general health perception. The results regarding the optimal dose are inconsistent. CONCLUSIONS: RTP improves strength, functional capacity, balance, and fatigue in people with MS. Registration: (PROSPERO): CRD42020182781Implications for rehabilitationResistance training is a valid strategy to improve isometric strength and functional capacity in MS patients.RTP using long durations (more than 6 weeks), high intensity (more than 80% 1-RM) and two-day weekly training frequency may be a correct stimulus to improve strength, functional capacity, balance, and fatigue in people with MS.Trainers and rehabilitators should consider these indicators in order to maximize muscular and functional adaptations in this population.

Differences in Health-Related Quality of Life and Physical Condition of Two Community-Based Exercise Programs in Subjects with Cardiovascular Risk Factors: A Prospective Observational Cohort Study.

We compared the effect of two community-based physical activity (PA) programs on health-related quality of life (HRQL) and physical condition in people with cardiovascular risk factors. Fifty-one subjects participated in the "ACTIVA Murcia" AM3 program characterized by non-individualized training loads for 3 months, and forty-two participated in the AM6 program characterized by individualized progressive training loads for 6 months. Both programs included a 6-month follow-up period without PA. HRQL was assessed with the Short Form 36 Health Survey (SF-36) and physical condition by VO2 max, strength, flexibility, and balance. Participants in the AM6 program as compared with those in the AM3 program showed significantly higher scores in the subscales of physical functioning, mental health, energy/vitality, and general health. Mental health and general health at 6 months of follow-up were also scored significantly higher by AM6 participants. VO2 max and flexibility improved more in the AM6 group, whereas strength was better in the AM3 group. Half of the participants in the AM6 program expressed a strong willingness to continue exercising vs. 38% in the AM3 program. In this study, a community-based PA program with individualized progressive training loads of 6-month duration showed a more favorable impact on HRQL than a 3-month non-individualized PA program.

Effects of fast-velocity concentric resistance training in people with multiple sclerosis: A randomized controlled trial.

OBJECTIVES: To analyze the effects of a fast-velocity concentric resistance training (FVCRT) program on maximum strength of upper and lower limb, gait speed, walking endurance, fatigue, physical self-perception, and catastrophizing pain in people with multiple sclerosis (MS). MATERIALS AND METHODS: Participants were randomized to either an experimental [EG] (n = 18) or a control [CG] (n = 12) group. The EG carried out 10-weeks of lower limb FVCRT. The CG did not perform any intervention. The maximum isometric voluntary contraction (MVIC) during knee extension, hand-grip strength, gait speed, walking endurance, fatigue, physical self-perception, and catastrophizing pain were measured. RESULTS: Inter-group differences after intervention were found on the right and left sides in MVIC (p = .032; ES = -0.7 and p = .009; ES = -0.9), and hand grip strength (p = .003; ES = -1.0 and p = .029; ES = -0.7). After FVCRT, there was in increase in MVIC (p < .001; ES = -1.7 and p < .001; ES = -1.3) and hand grip strength (p < .001; ES = -1.3 and p < .001; ES = -1.3) on both right and left sides, respectively. In addition, gait speed (p = .023; ES = 1.3), walking endurance (p < .001; ES = -1.0), symptomatic fatigue (p = .004; ES = 0.6), and catastrophizing pain (p < .001; ES = 1.0) improved in EG. CONCLUSION: Lower limb FVCRT improved the upper and lower limb strength, walking, symptomatic fatigue, and catastrophizing pain in MS participants.

Psychological, Physiological, and Physical Effects of Resistance Training and Personalized Diet in Celiac Women.

Background: Gluten intolerance is a systemic process of autoimmune nature; it develops in genetically predisposed subjects with gluten ingestion. The only treatment for celiac disease (CD) is a lifelong strict gluten-free diet (GFD). This study was designed to evaluate adherence to a GFD, risk of an eating disorder, and nutritional status in adult CD patients undergoing different interventions. Methods: A total of 28 Spanish women, aged 40 years or more, took part in a randomized controlled trial. Each group received a different intervention: group 1, gluten-free nutrition plan + exercise (GFD + E); group 2, gluten-free nutrition plan (GFD); group 3, celiac controls (NO-GFD); and group 4, non-celiac controls (CONTROL). The training was prescribed by a sport scientist. It was based on resistance training with elastic bands; beforehand a warm-up was performed and the resistance was increased progressively. The variables studied were adherence to the GFD, risk of eating disorders, blood values, and body composition. Results: Celiac women with personalized nutritional planning presented greater adherence to a gluten-free diet (p < 0.001). Regarding leukocytes, significant differences were observed between the GFD and control groups (p = 0.004). Perimeters and folds did not decrease significantly. Conclusion: Women with celiac disease who follow an adapted and personalized diet have a better adherence to a GFD compared to those who follow a non-professional diet, and therefore have a better immune system status (blood leukocytes).

Can strength training modify voluntary activation, contractile properties and spasticity in Multiple Sclerosis?: A randomized controlled trial.

BACKGROUND: A randomized controlled trial was conducted to analyze the effects of 10 weeks of strength training (ST) on voluntary activation, muscle activity, muscle contractile properties, and spasticity in people with MS. METHODS: 30 participants were randomized to either an experimental [EG] (n = 18) or a control [CG] (n = 12) group. The EG carried out 10-weeks of ST, where the concentric phase was performed at maximum voluntary velocity. Muscle activity of the vastus lateralis (surface electromyography (sEMG) during the first 200 ms of contraction), maximal neural drive (peak sEMG), voluntary activation (central activation ratio), and muscle contractile function (via electrical stimulation) of the knee extensor muscles, as well as spasticity, were measured pre- and post-intervention. RESULTS: The EG showed a significant improvement with differences between groups in muscle activity in EMG0-200 (p = 0.031; ES = -0.8) and maximal neural drive (p = 0.038; ES = -0.8), as well as improvement in the ST group with a trend towards significance in EMG0-100 (p = 0.068; ES = -0.6). CAR increased after intervention in ST group (p = 0.010; ES=-0.4). Spasticity also improved in the ST group, with differences between group after intervention, in first swing excursion (right leg: p = 0.006; ES = -1.4, left leg: p = 0.031; ES = -1.2), number of oscillations (right leg: p = 0.001; ES = -0.4, left leg: p = 0.031; ES = -0.4) and duration of oscillations (left leg: p = 0.002; ES = -0.6). Contractile properties remain unchanged in both ST group and CG. CONCLUSIONS: 10 weeks of ST improves muscle activity during the first 200 ms of contraction, maximal neural conduction, and spasticity in people with MS. However, ST does not produce adaptations in muscle contractile properties in this population.

The Impact of Resistance Training Program on Static Balance in Multiple Sclerosis Population: A Randomized Controlled Trial Study.

BACKGROUND: Multiple sclerosis (MS) is a neurological disease that affects balance. Among the non-pharmacological strategies to improve this variable, physical exercise is one of the most widely used. However, the benefits of some types of training, such as resistance training, on static balance in this population are still unclear. This study aims to analyze the effects of a resistance training (RT) intervention on balance in people with MS. METHODS: Thirty people with MS were randomized to either an experimental (n = 18) or a control (n = 12) group. The RT group performed 10 weeks of lower limb resistance training with a concentric phase at maximum velocity. Static balance was measured before and after intervention. RESULTS: No significant group × time interaction effects were found (ANOVA test) in any of the variables at the end of the intervention. No intragroup differences were found before or after the intervention in the balance variables. CONCLUSIONS: Resistance training with a concentric phase at maximum velocity showed no impact on balance in our sample. Future studies should examine programs of longer duration or combined with other types of training, such as balance training, with the aim of obtaining improvements in this variable in people with MS.

Personalised Nutritional Plan and Resistance Exercise Program to Improve Health Parameters in Celiac Women.

Celiac disease (CD) is a permanent immune reaction to gluten in those with a genetic predisposition. This study was designed to evaluate menopause-associated symptoms, mood, bone quality, and IgA antibody levels in women with CD, untreated and treated with a gluten-free diet (GFD), and with or without resistance exercise. The randomised controlled trial was conducted on 28 Spanish women (>40 years old). Participants were divided into the following intervention groups: personalised gluten-free nutrition plan + exercise (GFD + E); personalised gluten-free nutrition plan (GFD); celiac controls (NO-GFD); and non-celiac controls (CONTROL). The participants responded to the Menopause Rating Scale and the Profile of Mood States (POMS) questionnaires. Bone quality was measured with ultrasound and IgA with a blood test. After 12 weeks of intervention, the GFD + E group showed significant improvement in urogenital symptoms and scored higher on the 'vigour' subscale of the POMS. Negative associations were found between the total score on the Menopause Rating Scale and the 'vigour' subscale of the POMS questionnaire. Only those women who underwent a personalised GFD nutritional intervention combined with resistance exercise demonstrated significant changes after the intervention.

Factors that affect heart rate variability following acute resistance exercise: A systematic review and meta-analysis.

BACKGROUND: There is controversial evidence regarding the effect of acute resistance exercise (ARE) on heart rate variability (HRV) parameters, which indicates the activities of the cardiac autonomic nervous system. The aim of this study was to perform a systematic review and meta-analysis of the literature on the effect of ARE on HRV parameters and identify its possible moderating factors. METHODS: The PubMed-Medline, Web of Science, SPORTDiscus, and Cochrane Library databases were searched. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) declaration was followed, and the methodological quality of the studies was evaluated. The level of significance was set at p ≤ 0.05. Twenty-six studies met the inclusion criteria. Main effect analyses between pre- and post-test interventions demonstrated an increase in normalized units low frequency (p < 0.001; standardized mean difference (SMD) = 0.78; 95% confidence interval (95%CI): 0.46‒1.11) and low frequency/high frequency ratio (p < 0.001; SMD = 0.82; 95%CI: 0.64‒0.99) and a decrease in standard deviation of the normal-to-normal (NN) interval (p < 0.001; SMD = -0.58; 95%CI: -0.85 to -0.30), root mean square of the successive differences (p < 0.001; SMD = -1.01; 95%CI: -1.29 to -0.74), and normalized units high frequency (p < 0.001; SMD: -1.08; 95%CI: -1.43 to -0.73) following ARE in healthy individuals range: 15 ± 1 to 48 ± 2 years; mean ± SD). RESULTS: There were differences between the subgroups in the number of sets used in an exercise (p = 0.05) for root mean square of the successive differences, as well as for exercise intensity (p = 0.01) and rest between sets (p = 0.05) for normalized units high frequency. Interestingly, there were differences between the subgroups in training volume for root mean square of the successive differences (p = 0.01), normalized units high frequency (p = 0.003) and normalized units low frequency (p = 0.02). CONCLUSION: Overall, there was a withdrawal of cardiac parasympathetic and activation of cardiac sympathetic modulations following ARE, and these changes were greater with higher training volume ∼30 min after ARE in healthy individuals. Furthermore, the number of sets, intensity, and rest between sets affected HRV parameters. However, gender, body mass index, and training status did not influence the changes in HRV parameters as a response to ARE.

10-Weeks of resistance training improves sleep quality and cardiac autonomic control in persons with multiple sclerosis.

PURPOSE: To examine the acute and chronic effects of 10-weeks of progressive resistance training on sleep quality and sleeping heart rate variability in persons with Multiple Sclerosis (pwMS). METHODS: Eighteen pwMS (age = 44.8 ± 10.6 years; EDSS = 3.1 ± 1.7) completed a 10-week of resistance training, with three training sessions per week. Each session consisted of 4 lower body exercises, performing 2-4 sets of each exercise, with 8-15 repetitions each set, at an intensity ranging from 60 to 75% of 1-repetition maximum. Subjective and actigraphic sleep quality and sleeping heart rate variability were carried out at 4 different times: (1) Before the starting of the intervention on a rest day; (2) the night after training week 1 (3) the night after training week 10 and 4) after completing the resistance training program on a rest day. RESULTS: Regarding subjective sleep quality, significant main effects were observed on the variables of sleep quality, sleep comfort, easy of falling sleep, easy of waking up and felling of rest. Sleep quality, sleep comfort and easy of falling sleep were greater in rest night in week 1 vs. rest night in week 10. Actigraphic sleep quality also improved after the training program (rest night in week 1 vs. rest night in week 10). In the pair-wise comparison showed an acute effect in the session after the training program (rest night in week 10< training night in week 10) on HF, pNN50 and RMMSD. CONCLUSIONS: Resistance training is a non-pharmacological treatment that has the capacity to improve the regulation of autonomic system and, consequently, the sleep quality in pwMS.Implications for rehabilitation10 Weeks of resistance training improves the sleep quality of persons with multiple sclerosis.Resistance training can modulate autonomic cardiac control in this population.Improving the sleep quality is essential for persons with MS because of its close relationship to other variables, such as symptomatic fatigue.

A 12-Week Randomized Double-Blind Placebo-Controlled Clinical Trial, Evaluating the Effect of Supplementation with a Spinach Extract on Skeletal Muscle Fitness in Adults Older Than 50 Years of Age.

The aim of a 12-week randomized double-blind placebo-controlled study was to assess the effect of daily supplementation with a natural extract of Spinacia oleracea L. (4 × 500 mg capsules/day; total 2 g per day) combined with a moderate-intensity training program (1 h session/3 times a week) on skeletal muscle fitness in adults over 50 years of age. Muscle strength assessed by isokinetic and isometric dynamometry improved significantly in the experimental (n = 23) and the placebo (n = 22) groups, but the magnitude of improvement was higher in the experimental group, with between-group differences in almost all variables, including isokinetic at 60° s-1 in knee extension, peak torque (p < 0.007); total work per repetition maximum (p < 0.009); isokinetic at 180°s-1 in knee extension, peak torque (p < 0.002); total work (p < 0.007); total work per repetition maximum (p < 0.005); average power (p < 0.027); isometric in knee extension, peak torque (p < 0.005); and average peak torque (p < 0.002). Similar findings were observed for muscle quality. Changes in quality of life (SF-36) were not found, except for improvements in the role physical (p < 0.023) and role emotional (p < 0.001) domains, likely as a result of the physical training sessions. A nutritional survey did not revealed changes in dietary habits. No adverse events were recorded. In subjects over 50 years of age, moderate-intensity strength training combined with daily supplementation for 12 weeks with a natural extract of Spinacia oleracea L. improved muscle-related variables and muscle quality. Maintaining muscle health is a key component of healthy aging.

Effect of 12 Weeks Core Training on Core Muscle Performance in Rhythmic Gymnastics.

BACKGROUND: Rhythmic gymnastics performance is characterized by technical elements involving flexibility, aerobic capacity and strength. Increased core strength in rhythmic gymnastics could lead to improved sporting performance. OBJECTIVE: The aim of this study was to analyze the effect of 12 weeks of core muscle training on core muscle performance in rhythmic gymnasts. METHODS: A randomized controlled study involving 24 rhythmic gymnastics was conducted. Participants were randomly assigned to a control group (CG; n = 12; age 13.50 ± 3.17 years) or a training group (TG; n = 12; age 14.41 ± 2.35 years). Body composition, isometric strength of trunk, core endurance and core muscle electromyographic activity were measured (EMG) after 12 weeks of core training. Independent sample t-tests were carried out to compare baseline values between groups. A two-way repeated-measures analysis of variance (ANOVA) (time × group) was applied. RESULTS: The TG improved body composition, trunk lean mass (mean differences MD = -0.31; p = 0.040), lean mass (MD = 0.43; p = 0.037) and bone mass (MD = -0.06; p < 0.001) after training. Core training increased isometric strength of trunk, flexion test (MD = -21.53; p = 0.019) and extension test (MD = 22.7; p = 0.049), as well as the prone bridge core endurance test (MD = -11.27; p = 0.040). The EMG values also increased in the TG in prone bridge for front trunk (MD = -58.58; p = 0.026). CONCLUSIONS: Core strength training leads to improvements in body composition, as well as improvements in trunk strength and increases in muscle electromyographic activity. These improvements could therefore improve performance during competitive rhythmic gymnastics exercises.

Impact of Lockdown during COVID-19 Pandemic on Central Activation, Muscle Activity, Contractile Function, and Spasticity in People with Multiple Sclerosis.

BACKGROUND: People with multiple sclerosis (MS) suffer from symptoms related to neural control, such as reduced central activation, lower muscle activity, and accentuated spasticity. A forced 9-week home confinement related to COVID-19 in Spain may have worsened these symptoms. However, no study has demonstrated the impact of home confinement on neuromuscular mechanisms in the MS population. This study was aimed at analyzing the effects of a 9-week home confinement on central activation, muscle activity, contractile function, and spasticity in MS patients. METHODS: Eighteen participants were enrolled in the study. Left and right knee extensor maximum voluntary isometric contraction (MVIC), maximal neural drive via peak surface electromyography (EMG) of the vastus lateralis, central activation ratio (CAR), and muscle contractile function via electrical stimulation of the knee extensor muscles, as well as spasticity using the pendulum test, were measured immediately before and after home confinement. RESULTS: Seventeen participants completed the study. CAR significantly decreased after lockdown (ES = 1.271, p < 0.001). Regarding spasticity, there was a trend to decrease in the number of oscillations (ES = 0.511, p = 0.059) and a significant decrease in the duration of oscillations (ES = 0.568, p = 0.038). Furthermore, in the left leg, there was a significant decrease in the first swing excursion (ES = 0.612, p = 0.027) and in the relaxation index (ES = 0.992, p = 0.001). Muscle contractile properties, MVIC, and EMG variables were not modified after confinement. CONCLUSIONS: The results suggest that a home confinement period of 9 weeks may lead to an increase in lower limb spasticity and a greater deficit in voluntary activation of the knee extensors.

Effect of High-Intensity Interval Training and Intermittent Fasting on Body Composition and Physical Performance in Active Women.

Nutritional strategies may have an effect on body composition and physical performance. Intermittent fasting (IF) is an eating pattern that cycles between periods of eating and fasting in specified time periods. Moreover, it is a common strategy among members of the athlete population that are looking for weight loss. However, this strategy may negatively affect physical performance, as compared to other weight loss strategies. The main purpose of this research was to use a cross-over design to study the effects of HIIT, with or without intermittent fasting, on muscular and anaerobic performance in 14 active women (27 ± 6 y). To assess performance, body composition (anthropometry), hand-grip strength, and counter-movement jump (CMJ) height was measured, and a 30 s Wingate test was completed assessed. HIIT + IF reduced fat mass (1 kg, p < 0.05, d = 1.1; 1.5%, p < 0.01, d = 1.0) and increased CMJ height (6.2 cm, p < 0.001, d = 1.8). In addition, the change in CMJ height in HIIT + IF was higher over HIIT (5.2 cm, p < 0.001, d = 1.9). In conclusion, intermittent fasting could be a nutritional strategy to decrease fat mass and increase jumping performance. However, longer duration programs would be necessary to determine whether other parameters of muscle performance could be positively affected by IF.