The Duration of Non-Local Muscle Fatigue Effects.

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.

Neuromechanical Differences between Pronated and Supinated Forearm Positions during Upper-Body Wingate Tests.

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.

Does infant formula containing synbiotics support adequate growth in infants? A meta-analysis and systematic review of randomized controlled trials.

In recent years, several studies have shown that formulas that contain synbiotics, i.e. composed prebiotics and probiotics have been proposed to have a beneficial effect on anthropometric indices. However, the results are inconsistent thus this meta-analysis was performed to assess this effect. PubMed/MEDLINE, Web of Science, SCOPUS, and Embase were systematically searched up to May-2020. Weight gain, length gain, head circumstance gain, weight-for-age z scores, and length-for-age z scores were considered as the outcomes. Weighted mean differences (WMD) with the 95% CI were applied for estimating the combined effect size. Subgroup analysis was performed to specify the source of heterogeneity among studies. Consumption of formulas containing synbiotics did not affect growth significantly in healthy infants (weight gain (WMD = 2.06, 95% CI: - 4.08 to 8.21; p = 0.51), length gain (WMD = - 0.05, 95% CI: - 0.70 to 0.60; p = 0.88), head circumstance (WMD = - 0.28, 95% CI: - 0.66 to 0.11; p = 0.15), on weight-for-age z-scores (WMD = - 0.05, 95% CI: - 0.23 to 0.13; p = 0.57) and length-for-age z-scores (WMD = - 0.16, 95% CI: - 0.50 to 0.19; p = 0.37)). The main results indicate a non-significant increase in infant's growth following synbiotics supplementation of infant formula. Further large-scale studies are warranted to confirm present findings.

Corticospinal excitability and reflex modulation in a contralateral non-stretched muscle following unilateral stretching.

PURPOSE: Muscle stretching effect on the range of motion (ROM) and force deficit in non-stretched muscle, and the underlying mechanisms, is an ongoing issue. This study aimed to investigate crossover stretching effects and mechanisms on the plantar flexor muscles. METHODS: Fourteen recreationally active females (n = 5) and males (n = 9) performed six sets of 45-s static stretching (SS) (15-s recovery) to the point of discomfort of the dominant leg (DL) plantar flexors or control (345-s rest). Participants were tested for a single 5-s pre- and post-test maximal voluntary isometric contraction (MVIC) with each plantar flexor muscle and were tested for DL and non-DL ROM. They were tested pre- and post-test (immediate, 10-s, 30-s) for the Hoffman (H)-reflex and motor-evoked potentials (MEP) from transcranial magnetic stimulation in the contralateral, non-stretched muscle. RESULTS: Both the DL and non-DL-MVIC force had large magnitude, significant (↓10.87%, p = 0.027, pƞ2 = 0.4) and non-significant (↓9.53%, p = 0.15, pƞ2 = 0.19) decreases respectively with SS. The SS also significantly improved the DL (6.5%, p < 0.001) and non-DL (5.35%, p = 0.002) ROM. The non-DL MEP/MMax and HMax/MMax ratio did not change significantly. CONCLUSION: Prolonged static stretching improved the stretched muscle's ROM. However, the stretched limb's force was negatively affected following the stretching protocol. The ROM improvement and large magnitude force impairment (statistically non-significant) were transferred to the contralateral muscles. The lack of significant changes in spinal and corticospinal excitability confirms that the afferent excitability of the spinal motoneurons and corticospinal excitability may not play a substantial role in non-local muscle's ROM or force output responses.

The Effect of a Mental Task Versus Unilateral Physical Fatigue on Non-Local Muscle Fatigue in Recreationally Active Young Adults.

Non-local muscle fatigue (NLMF) has been attributed to both physical and mental fatigue. The purpose of this study was to investigate the effects of mental exertion versus unilateral physical fatigue on NLMF. Sixteen recreationally active participants completed a physical task (2-sets of 100-s unilateral knee extension (KE) maximal voluntary isometric contractions (MVIC) with the dominant leg with 40-s recovery between sets, mental task (4-minute Stroop task), and control condition. Before and after each condition, blood lactate was collected, and contralateral 5-s KE, flexion (KF) and bilateral lateral trunk flexors MVIC (measure of trunk stability strength) was performed. Following the post-test 5-s MVICs, participants performed 12 non-dominant KE MVICs with a work-to-rest ratio of 5/10-s. Electromyography was monitored during the MVICs. Neither the 4-minute Stroop test or the unilateral KE physical fatigue intervention adversely affected the non-dominant KE forces or EMG activity with a single MVIC or 12 repetition MVICs. Although the non-dominant KF fatigue index forces and hamstrings EMG were not impaired by the interventions, there was a significant interaction (p = 0.001) small magnitude (d = 0.42) decrease in the non-dominant KF single MVIC force following the contralateral fatigue intervention, albeit with no significant change in hamstrings EMG. This MVIC deficit may be related to the significant decrease in dominant (p = 0.046, d = 2.6) and non-dominant external obliques (p = 0.048, d = 0.57) activation adversely affecting trunk stability. In conclusion, a 4-minute Stroop test or unilateral KE physical fatigue intervention did not impair non-dominant KE single or repeated 12 repetition MVIC forces or EMG activity. The small magnitude deficit in the non-dominant KF single MVIC force following the contralateral fatigue intervention are in accord with the heterogenous findings common in the literature.

Maximal and Submaximal Intensity Isometric Knee Extensions Induce an Underestimation of Time Estimates with Both Younger And Older Adults: A Randomized Crossover Trial.

Our perception of time plays a critical role in nearly all daily activities and especially in sports. There are no studies that have investigated and compared time perception during exercise in young and older adults. Thus, this study aimed to compare the effects of exercise on time perception between younger and older adult populations. Thirty-three recreationally active participants were recruited and assigned to either the younger (university students, 9 males and 10 females) or older adults (>60 years, 8 males and 6 females). All participants completed four exercise conditions over two sessions on separate days: approximately 30-seconds of knee extensors 100%, 60% and 10% of maximum voluntary isometric contraction (MVIC), and control (no contractions). Prospective time perception was estimated (at 5-, 10-, 20-, and 30-seconds) at the beginning of each session and while performing the exercise. A main effect for condition (p < 0.001, d = 1.06) with subsequent post-hoc tests indicated participants significantly underestimated (estimated time was shorter than chronological time) time in all three exercise conditions compared to the control. There were no significant age group differences. In conclusion, exercise underestimated time estimates regardless of intensity or age. This questions the postulated intensity-dependent relationship between exercise and time perception. While older adults were expected to be less accurate in their time estimates, they may have been able to adopt alternative strategies for age-related changes in their internal clock, resulting in no significant age group differences.

Are Acute Effects of Foam-Rolling Attributed to Dynamic Warm Up Effects? A Comparative Study.

Over the last decade, acute increases in range of motion (ROM) in response to foam rolling (FR) have been frequently reported. Compared to stretching, FR-induced ROM increases were not typically accompanied by a performance (e.g., force, power, endurance) deficit. Consequently, the inclusion of FR in warm-up routines was frequently recommended, especially since literature pointed out non-local ROM increases after FR. However, to attribute ROM increases to FR it must be ensured that such adaptations do not occur as a result of simple warm-up effects, as significant increases in ROM can also be assumed as a result of active warm-up routines. To answer this research question, 20 participants were recruited using a cross-over design. They performed 4x45 seconds hamstrings rolling under two conditions; FR, and sham rolling (SR) using a roller board to imitate the foam rolling movement without the pressure of the foam rolling. They were also tested in a control condition. Effects on ROM were tested under passive, active dynamic as well as ballistic conditions. Moreover, to examine non-local effects the knee to wall test (KtW) was used. Results showed that both interventions provided significant, moderate to large magnitude increases in passive hamstrings ROM and KtW respectively, compared to the control condition (p = 0.007-0.041, d = 0.62-0.77 and p = 0.002-0.006, d = 0.79-0.88, respectively). However, the ROM increases were not significantly different between the FR and the SR condition (p = 0.801, d = 0.156 and p = 0.933, d = 0.09, respectively). No significant changes could be obtained under the active dynamic (p = 0.65) while there was a significant decrease in the ballistic testing condition with a time effect (p < 0.001). Thus, it can be assumed that potential acute increases in ROM cannot be exclusively attributed to FR. It is therefore speculated that warm up effects could be responsible independent of FR or imitating the rolling movement, which indicates there is no additive effect of FR or SR to the dynamic or ballistic range of motion.

Metabolic phenotypes and risk of colorectal cancer: a systematic review and meta-analysis of cohort studies.

BACKGROUND: The association of obesity with colorectal cancer (CRC) may vary depending on metabolic status. OBJECTIVE: This meta-analysis aimed to investigate the combined impacts of obesity and metabolic status on CRC risk. METHODS: The Scopus, PubMed, and web of sciences databases were systematically searched up to Jun 2021 to find all eligible publications examining CRC risk in individuals with metabolically unhealthy normal-weight (MUHNW), metabolically healthy obesity (MHO), and metabolically unhealthy obesity (MUHO) phenotypes. RESULTS: A total of 7 cohort studies with a total of 759,066 participants were included in this meta-analysis. Compared with healthy normal-weight people, MUHNW, MHO, and MUHO individuals indicated an increased risk for CRC with a pooled odds ratio of 1.19 (95% CI = 1.09-1.31) in MUHNW, 1.14 (95% CI = 1.06-1.22) in MHO, and 1.24 (95% CI = 1.19-1.29) in MUHO subjects. When analyses were stratified based on gender, associations remained significant for males. However, the elevated risk of CRC associated with MHO and MUHO was not significant in female participants. CONCLUSIONS: The individuals with metabolic abnormality, although at a normal weight, have an increased risk for CRC. Moreover, obesity is associated with CRC irrespective of metabolic status.

Interaction of MC4R rs17782313 variants and dietary carbohydrate quantity and quality on basal metabolic rate and general and central obesity in overweight/obese women: a cross-sectional study.

BACKGROUND: Recent studies have shown that dietary carbohydrate quantity and quality as well as genetic variants may contribute to determining the metabolic rate and general and central obesity. This study aimed to examine interactions between melanocortin 4 receptor gene (MC4R) rs17782313 and dietary carbohydrate intake, glycemic index (GI), and glycemic load (GL) on body mass index (BMI), waist circumferences (WC), basal metabolic rate (BMR), and BMR/kg in overweight/obese women. METHODS: A total of 282 Iranian women (BMI ≥ 25) aged 18-56 years were enrolled in this cross-sectional study. All participants were assessed for blood parameters, body composition, BMR, and dietary intake. Dietary carbohydrate intake, GI, and GL were determined using a valid, reliable 147-item food frequency questionnaire. MC4R rs17782313 was genotyped by the restriction fragment length polymorphism (PCR-RFLP) method. RESULTS: After adjustment for age and energy intake, significant interactions were observed between carbohydrate intake and MC4R rs17782313 in terms of BMI (P Interaction = 0.007), WC (P Interaction = 0.02), and BMR/kg (P Interaction = 0.003) in this way that higher carbohydrate intake, compared with lower intake, was associated with an increase in BMI and WC for individuals with C allele carriers (TC + CC genotypes), while related to an increase in BMR/kg for those carrying the TT genotype. No significant interaction was found between MC4R rs17782313 and GI and GL on BMI, WC, BMR/kg, and BMR. CONCLUSIONS: Interactions between the MC4R rs17782313 and carbohydrate intake probably can have an effect on BMI, WC, and BMR/kg in overweight/obese women.

Dietary Inflammatory Index in relation to Type 2 Diabetes: A Meta-Analysis.

Background and Aims: Epidemiologic studies show a strong association between chronic inflammation and type 2 diabetes (T2D). Diet may also affect the risk of T2D by modulating inflammation. This meta-analysis aimed to assess the relation of dietary inflammatory index (DII) and risk of T2D. Methods: PubMed and Scopus were systematically searched from their inception to September 2020 to identify relevant studies. Relative risks, hazard ratios, or odds ratios (OR), with their corresponding 95% confidence intervals (95% CI), were calculated and pooled using a random-effects model. Results: A total of 48 different studies, with a total sample size of 1,687,424 participants, were eligible to be included in this meta-analysis. In the overall analysis, no significant association was observed between DII and risk of T2D (OR = 1.03, 95% CI: 0.91 to 1.15), with significant evidence for heterogeneity (I 2 = 96.5%, P < 0.001); however, higher DII was identified as being significantly related to increased risk of T2D in high quality studies (OR = 1.58, 95% CI: 1.15 to 2.17). In the stratified analysis by the dietary assessment tool, background disease, and sex of participants, DII showed no significant association with T2D. Conclusions: Higher DII might be associated with an increased risk of T2D. Additional well-designed studies are required to confirm this finding.

Mercury Exposure and Risk of Type 2 Diabetes: A Systematic Review and Meta-Analysis.

Methods: Scopus and PubMed databases were systematically searched from their inception to November 2021 to obtain pertinent studies. Standardized mean differences (SMDs) with corresponding 95% confidence intervals (CIs) were calculated to evaluate the difference in Hg levels between people with and without T2DM. The association of the Hg exposure with T2DM was assessed using a random-effects model by pooling the odds ratios (ORs) and 95% CIs. Results: A total of 17 studies, with 42,917 participants, aged ≥18 years, were analyzed. Overall, Hg levels were significantly higher in T2DM patients compared with non-T2DM controls (SMD = 1.07; 95%CI = 0.59 to 1.55, P ≤ 0.001), with significant heterogeneity across studies (I2 = 96.1%; P=≤0.001). No significant association was found between Hg exposure and risk of T2DM in the overall analysis and subgroup analysis based on the source of sample and study design. However, higher exposure to Hg was related to reduced risk of T2DM in men (OR = 0.71; 95%CI = 0.57 to 0.88), but not in women. No significant evidence for publication bias was detected. Conclusions: Although the Hg level in T2DM is significantly higher than that of nondiabetics, there was no association between Hg exposure and the overall risk of T2DM. Nevertheless, our study shows that higher exposure to Hg might reduce the risk of T2DM in men.

The effect of ß-caryophyllene on food addiction and its related behaviors: A randomized, double-blind, placebo-controlled trial.

Food addiction (FA) is a psychological construct that may be involved in the etiology of obesity. The cannabinoid system is involved in the addictive-like food preferences by acting on the dopaminergic pathway of the brain. ß-caryophyllene is a dietary cannabinoid that is a cannabinoid type 2 (CB2) receptor agonist. This study explored the impacts of ß-caryophyllene supplementation on eating behavior, appetite, mental health, anthropometric parameters, body composition, and some hormones related to appetite in women with obesity diagnosed with FA. Women with obesity and FA, diagnosed by the Yale Food Addiction Scale Score (YFAS-S) ≥3, were randomly allocated to receive a ß-caryophyllene softgel (n = 26) (100 mg/daily with meal) or placebo (n = 26) for 8 weeks. Anthropometric measurements, body composition, eating behavior, biochemical markers, dietary intake, appetite, stress, anxiety, and depression were evaluated during the study period. ß-caryophyllene administration significantly reduced YFAS-S compared to the placebo group (changes in FA score: 1.5 ± 0.9 vs. - 0.7 ± 1.4; corrected P = 0.05). Serum levels of orexin-A significantly decreased in the ß-caryophyllene group (p = 0.02); however, no significant difference was observed compared to the placebo group (corrected P = 0.09). ß-caryophyllene supplementation had no significant effect on body composition, anthropometric indices, appetite, eating behavior, dietary intake, physical activity level, mental health, and levels of oxytocin and neuropeptide Y (NPY), compared to the placebo. ß-caryophyllene supplementation may have beneficial effects on improving YFAS-S in women with obesity diagnosed with FA. TRIAL REGISTRATION: Iranian Registry of Clinical Trials identifier: IRCT20200914048712N1.

The effect of Brassica vegetables on blood glucose levels and lipid profiles in adults. A systematic review and meta-analysis.

Previous studies on the effect of Brassica vegetables on blood glucose and lipid profile have reported inconclusive findings. Due to the high prevalence of glucose and lipid metabolism disorders and their importance as predictors of chronic diseases, the present meta-analysis was performed to clarify the effect of Brassica vegetables on blood glucose and lipid profile. A systematic search of the databases of PubMed, Scopus, and Cochran Library was performed up to October 2020. All randomized controlled trials (RCTs) that examined the effect of Brassica vegetables on blood glucose and lipid profile were included in the study. The search results were limited to English-language publications. Finally, nine RCTs, including 548 participants, were selected for the present study. Pooled analysis indicated a significant reduction in total cholesterol (TC) (SMD = -0.28, 95%CI: 0.48 to 0.08; p = 0.005) following Brassica vegetables consumption. Overall, Brassica vegetables had no significant impact on serum levels of triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, fasting blood sugar, and glycated hemoglobin. Consumption of Brassica vegetables had a statistically significant effect on TC concentration. However, further high-quality studies are needed to firmly establish the clinical efficacy of these plants.

Effect of curcumin on C-reactive protein as a biomarker of systemic inflammation: An updated meta-analysis of randomized controlled trials.

It has been suggested that curcumin is a potential agent for lowering the levels of C-reactive protein (CRP) and high-sensitivity CRP (hs-CRP), as markers of inflammation. In the current meta-analysis, we attempted to clarify the efficacy of curcumin supplementation in lowering the concentrations of CRP and hs-CRP in patients with autoinflammatory conditions. Nine studies were found evaluating the effect of curcumin on CRP levels, while 23 studies were identified for hs-CRP. CRP concentration was decreased significantly compared to the placebo (WMD = -3.67 mg/L, 95% CI = -6.96 to -0.38, p = 0.02). There was a significant effect of curcumin at dose ≤1,000 mg/day on the CRP concentration. CRP concentration significantly decreased after >10-week intervention compared with placebo.hs-CRP concentration in the intervention group was significantly lower than that of placebo group. A significant effect of curcumin consumption was detected on the serum level of hs-CRP in studies with prescribing ≤1,000 mg/day, and those with ≤10-week duration of intervention. Curcumin consumption resulted in a reduction of hs-CRP in a non-linear fashion with stronger effects with less than 2000 mg curcumin per day. Curcumin seems to be beneficial in decreasing the hs-CRP and CRP levels in proinflammatory settings.

The negative impact of obesity on the occurrence and prognosis of the 2019 novel coronavirus (COVID-19) disease: a systematic review and meta-analysis.

PURPOSE: The 2019 novel coronavirus (COVID-19) is an emerging pandemic, with a disease course varying from asymptomatic infection to critical disease resulting to death. Recognition of prognostic factors is essential because of its growing prevalence and high clinical costs. This meta-analysis aimed to evaluate the global prevalence of obesity in COVID-19 patients and to investigate whether obesity is a risk factor for the COVID-19, COVID-19 severity, and its poor clinical outcomes including hospitalization, intensive care unit (ICU) admission, need for mechanical ventilation, and mortality. METHODS: The study protocol was registered in PROSPERO (CRD42020203386). A systematic search of Scopus, Medline, and Web of Sciences was conducted from 31 December 2019 to 1 June 2020 to find pertinent studies. After selection, 54 studies from 10 different countries were included in the quantitative analyses. Pooled odds ratios (OR) with 95% confidence intervals (CIs) were calculated to assess the associations. RESULTS: The prevalence of obesity was 33% (95% CI 30.0%-35.0%) among patients with COVID-19. Obesity was significantly associated with susceptibility to COVID-19 (OR = 2.42, 95% CI 1.58-3.70; moderate certainty) and COVID-19 severity (OR = 1.62, 95% CI 1.48-1.76; low certainty). Furthermore, obesity was a significant risk factor for hospitalization (OR = 1.75, 95% CI 1.47-2.09; very low certainty), mechanical ventilation (OR = 2.24, 95% CI 1.70-2.94; low certainty), intensive care unit (ICU) admission (OR = 1.75, 95% CI 1.38-2.22; low certainty), and death (OR = 1.23, 95% CI 1.06-1.41; low certainty) in COVID-19 patients. In the subgroup analyses, these associations were supported by the majority of subgroups. CONCLUSION: Obesity is associated with COVID-19, need for hospitalization, mechanical ventilation, ICU admission, and death due to COVID-19. LEVEL OF EVIDENCE: Level I, systematic reviews and meta-analyses.

Menthol-Based Topical Analgesic Induces Similar Upper and Lower Body Pain Pressure Threshold Values: A Randomized Trial.

CONTEXT: Both health professionals and consumers use menthol-based topical analgesics extensively for the temporary relief of pain from musculoskeletal ailments or injury. However, there are no reports of differences in the pain pressure threshold (PPT) or the relative effectiveness of topical analgesics to reduce pain in the upper and lower body muscles and tendons. The objective of this study was to investigate whether differences existed in PPT and relative pain attenuation associated with a menthol-based topical analgesic over a variety of upper and lower body muscles and tendons. DESIGN: Randomized allocation, controlled, intervention study. METHODS: Sixteen participants (10 females and 6 males) were tested on their dominant or nondominant side. The order of specific muscle/tendon testing was also randomized, which included upper body (middle deltoid, biceps brachii, and lateral epicondylar tendon) and lower body locations (quadriceps, hamstrings, gastrocnemius, lumbosacral erector spinae muscles, and patellar and Achilles tendons). The PPT was monitored before and 15 minutes following the application of a menthol-based topical analgesic. RESULTS: A menthol-based topical analgesic increased PPT (decreased pain sensitivity) overall (P = .05; 11.6% [2.4%]; d = 1.05) and PPT was higher (P < .0001; 31.5%-44.2%; d = 1.03-1.8) for lower versus upper body locations. CONCLUSIONS: Health professionals and the public can be assured of similar reductions in pain sensitivity independent of the location of application of a menthol-based topical analgesic.

The Effect of Shoulder Injury Prevention Program on Shoulder Isokinetic Strength in Young Male Volleyball Players.

The purpose of this study was to examine the effects of an eight-week 11 + S programme on isokinetic shoulder strength in young male volleyball players. Twenty-eight top-level young male volleyball players were recruited for this study. The players were randomly assigned into intervention (14 players) and control (14 players) groups. The intervention group performed the 11 + S as a warm-up before training at least three times a week for eight weeks. Dominant shoulder strength was measured using an isokinetic dynamometer at 60°/s and 180°/s. The functional deceleration ratio (FDR) was calculated as a functional strength profile. 20% FDR improvement after eight weeks of 11 + S at 180°/s (p = 0.003) were observed. No other statistically significant effects for shoulder strength improvement was observed (p > 0.05). Eight weeks of 11 + S warm-up programme improved the glenohumeral muscle imbalance by increasing the functional deceleration ratio (FDR) of shoulder muscles in young male volleyball players.

Lack of Evidence for Crossover Fatigue with Plantar Flexor Muscles.

The occurrence and mechanisms underlying non-local or crossover muscle fatigue is an ongoing issue. This study aimed to investigate crossover fatigue of the plantar flexor muscles. Sixteen recreationally active males (n = 6) and females (n = 10) visited the laboratory for four sessions and performed a single 5-s pre-test maximal voluntary isometric contraction (MVIC) with each plantar flexors muscle. Thereafter, the fatigue intervention involved two 100-s MVICs (60-s recovery) with their dominant plantar flexors or rested for 260-s (control). Subsequently, in two separate sessions, Hoffman reflexes (H-reflex) were evoked in the non-dominant, non-exercised, leg before and following the dominant leg fatigue or control intervention (Fatigue-Reflex and Control-Reflex conditions). MVIC forces and volitional (V)-waves were monitored in the non-dominant leg in the other two sessions (Fatigue-MVIC and Control-MVIC) before and after the intervention (fatigue or control) as well as during 12 repeated MVICs and immediately thereafter. Despite the force reduction in the dominant leg (42.4%, p = 0.002), no crossover force deficit with single (F(1,9) = 0.02, p = 0.88, pƞ2 = 0.003) or repeated (F(1,9) = 0.006, p = 0.93, pƞ2 = 0.001) MVIC testing were observed. The H-reflex did not change after the fatigue (F(1,7) = 0.51; p = 0.49; pƞ2 = 0.06) or repeated MVICs (F(1,8) = 0.27; p = 0.61; pƞ2 = 0.03). There were also no crossover effects of fatigue on the V-wave with single (F(1,8) = 3.71, p = 0.09, pƞ2 = 0.31) or repeated MVICs (F(1,6) = 1.45, p = 0.27, pƞ2 = 0.19). Crossover fatigue was not evident with the plantar flexors nor any significant changes in H-reflex and V-waves in the soleus muscle. This finding suggests that crossover fatigue may not necessarily occur in slow-twitch predominant muscle groups.

Effect of probiotic fermented dairy products on incidence of respiratory tract infections: a systematic review and meta-analysis of randomized clinical trials.

BACKGROUND: Previous studies have suggested that the consumption of probiotic fermented dairy products (PFDP) may have a protective effect on respiratory tract infections (RTIs). However, the results of studies are inconclusive. We aimed to systematically investigate the effect of PFDP on RTIs by performing a meta-analysis of randomized controlled trials (RCTs). METHODS: PubMed and Scopus databases were systematically searched up to October 2020 to identify eligible RCTs. Meta-analysis outcomes were risk of incidence of upper (URTIs ) and lower (LRTIs ) respiratory tract infections. A random-effects model was used to pool the relative risks (RR) and corresponding 95 % confidence intervals (CI) for outcomes following conception of PFDP. RESULTS: A total of 22 RCTs, with a total sample size of 10,190 participants, were included in this meta-analysis. Compared with placebo, consumption of PFDP had a significant protective effect against RTIs in the overall analysis (RR = 0.81, 95 %CI: 0.74 to 0.89) and in children (RR = 0.82, 95 %CI: 0.73 to 0.93), adults (RR = 0.81, 95 %CI: 0.66 to 1.00), and elderly population (RR = 0.78, 95 %CI: 0.61 to 0.98). The significant decreased risk of RTIs was also observed for URTIs (RR = 0.83, 95 %CI: 0.73 to 0.93), while, this effect was marginal for LRTIs (RR = 0.78, 95 %CI: 0.60 to 1.01, P = 0.06). The disease-specific analysis showed that PFDP have a protective effect on pneumonia (RR = 0.76, 95 %CI: 0.61 to 0.95) and common cold (RR = 0.68, 95 %CI: 0.49 to 0.96). CONCLUSIONS: Consumption of PFDP is a potential dietary approach for the prevention of RTIs.

Glycemic index, but not glycemic load, is associated with an increased risk of metabolic syndrome: Meta-analysis of observational studies.

BACKGROUND: Diets with high glycemic index (GI) or high glycemic load (GL) have been linked to important risk factors associated with the development of metabolic syndrome (MetS), such as dyslipidemia, higher blood glucose, and insulin concentrations. However, the role of GI and GL in relation to Mets is still understudied and controversial. This review, therefore, assessed whether high GI or GL contribute to development of Mets. METHODS: A systematic search of four bibliographic databases was conducted (MEDLINE/PubMed, EMBASE, Web of Sciences, and Scopus) from inception to January 2020 for observational studies assessing GI/GL in relation to MetS. Risk estimates were pooled using random-effect models for the highest versus lowest intake categories, and assessed for heterogeneity using subgroup analysis. The dose-response nature of the relationship was also investigated. Sensitivity analysis and Egger test were used to check the robustness of findings and the possibility of publication bias, respectively. RESULTS: Data from 12 publications (one cohort study and eleven cross-sectional studies) with a total sample size of 36,295 subjects are included. The pooled effect sizes from the nine studies indicated high versus low dietary GI was associated with increased risk of MetS (OR = 1.05, 95% CI: 1.01 to 1.09) (I2  = 58.1, P = .004). This finding was supported by all subgroup analyses except where studies used 24-h recalls for dietary assessment. Additionally, a linear dose-response investigation revealed that each 5-point increment in GI was associated with 2% increase in the risk of MetS (OR = 1.02, 95% CI: 1.01 to 1.02); non-linear pattern was insignificant, however (p-nonlinearity = 0.63). Moreover, pooled effect sizes from ten studies suggested that no association was found between the GL and MetS with results remaining consistent in all subgroup analyses. CONCLUSION: A diet with lower GI may protect against MetS. Nutrition policy and clinical practices should encourage a diet with low GI. Future studies should include both GI and GL and different criteria of MetS to provide a better comparison.