Right Hand Grip Strength Research Articles

Influence of participation in a health fitness program on the indicators of physical condition in adolescent underweight girls

The article presents the results of the study of the influence of participation in a health fitness program on the indicators of physical development, physical fitness and work capacity, physical activity in 12-13-year-old underweight girls. The objective of the study was to assess the impact of engagement in a health fitness program on the indicators of physical condition of adolescent underweight girls. To address the objective and tasks of the research, the following methods were used: analysis of special scientific and methodological literature and documentary materials, matching and comparison, anthropometric, physiological, and pedagogical methods, and mathematical statistics methods. Results. To determine the impact of participation in the health fitness program on the indicators of physical condition, a transformative pedagogical experiment was conducted, which lasted for 9 months. As performance criteria, indicators of physical condition were used, which, according to the results of previous studies, had a close correlation with the general level of physical condition, namely: physical activity (moderate level), physiometric indicators of physical development (grip strength of right and left hand), physical performance (Ruffier's test), indicators of physical fitness (tilting the trunk forward from a sitting position, 30 m run, 4 x 9 m shuttle run, raising the trunk in a sitting position). According to the results of the study, a probable improvement of the investigated indicators was found. The obtained results prove the effectiveness of the developed training program and demonstrate the expediency of its implementation for correcting indicators of girls’ physical condition. Conclusions. The evaluation of the effectiveness of the developed health fitness program showed that there were statistically significant changes in the indicators of physical fitness and physical performance of 12-13-year-old underweight girls, as well as in their somatometric and physiometric indicators of physical development and physical activity.

Bidirectional two-sample mendelian randomization analysis identifies causal associations between age at menarche and sarcopenia-related traits.

Observational studies have shown that the age of menarche is associated with sarcopenia, but confounding factors make the causal relationship difficult to infer. Therefore, we conducted a bidirectional two-sample Mendelian randomized (MR) analysis to evaluate the potential causal relationship between age at menarche and sarcopenia-related traits (hand grip strength, lean mass, walking pace). We obtained the latest aggregate statistics from the Genome-wide association studies (GWAS) database on the age of menarche of 182,416 participants from ReproGen, the appendicular lean mass of 244,730 participants from EMBL's European Bioinformatics Institute, the left-hand grip strength of 401,026 participants, the right-hand grip strength of 461,089 participants and the usual walking pace of 459,915 participants from the UK Biobank. The inverse variance weighting (IVW) method and other MR methods were used to evaluate the bidirectional causal relationship between the age of menarche and sarcopenia. The forward MR results showed that the age of menarche predicted by the gene was positively correlated with left-hand grip strength (IVWβ=0.041, P = 2.00×10-10), right-hand grip strength (IVWβ=0.053, P = 1.97×10-18), appendicular lean mass (IVWβ=0.012, P = 4.38×10-13) and usual walking pace (IVWβ=0.033, P = 1.62×10-8).In the reverse MR analysis, we also found that the usual walking pace was positively correlated with the age of menarche predicted by genes (IVWβ=0.532, P = 1.65×10-4). Still, there was no causal relationship between grip strength and appendicular lean mass and the age at menarche. Our results show that earlier menarche will increase the risk of sarcopenia. In addition, people with higher muscle function tend to have menarche later. These findings may provide a reference for prevention strategies and interventions for menarche in advance and sarcopenia.

Genetic Association and Potential Mediators between Sarcopenia and Coronary Heart Disease: A Bidirectional Two-Sample, Two-Step Mendelian Randomization Study.

To elucidate the bidirectional correlation of sarcopenia with coronary heart disease (CHD), as well as to investigate the mediating role of cardiometabolic factors and inflammatory biomarkers, a bidirectional two-sample, two-step Mendelian randomization (MR) study was conducted. Summary statistics were obtained from genome-wide association studies (GWAS). In our bidirectional two-sample MR, genetic variants associated with sarcopenia-related traits and CHD were instrumented for the estimation of bidirectional correlations. Besides, genetic variants associated with thirteen cardiometabolic factors and six inflammatory biomarkers were selected for further mediation analyses. To confirm the consistency of the results, several sensitivity analyses were carried out. Genetically predicted higher appendicular lean mass (OR = 0.835, 95% CI: 0.790-0.882), left hand grip strength (OR = 0.703, 95% CI: 0.569-0.869), right hand grip strength (OR = 0.685, 95% CI: 0.555-0.844), and walking pace (OR = 0.321, 95% CI: 0.191-0.539) reduced CHD risk, while genetic predisposition to CHD did not affect any of the sarcopenia-related traits. Seven mediators were identified for the effects of appendicular lean mass on CHD, including waist-to-hip ratio, hip circumference, systolic blood pressure, low-density lipoprotein cholesterol, total cholesterol, triglycerides, and fasting insulin. The mediation proportion ranged from 10.23% for triglycerides to 35.08% for hip circumference. Hip circumference was found to mediate the relationships between both left (mediation proportion: 24.61%) and right-hand grip strength (24.14%) and CHD, and the link between walking pace and CHD was partially mediated by waist-to-hip ratio (31.15%) and body mass index (26.66%). Our results showed that higher appendicular lean mass, hand grip strength, and walking pace reduced CHD risk, but the causal relationship was not bidirectional. Several mediators were found to mediate the causal pathways between sarcopenia-related traits and CHD, and intervention of these factors may be helpful in terms of CHD prevention in sarcopenia patients.

An Investigation of the Effects of Some Parameters on the Shooting Performance of Air Rifle Shooters in Terms of Gender and Level of Competition

The purpose of this study is to compare the effects of some parameters on the shooting performance of air rifle shootersin terms of gender and level of competition. To achieve this, 20 air rifle shooters who ranked in the Air Guns Turkey Cup and Air Guns Turkey Championships volunteered for the study. In this study, the height and body composition of the participants were measured, and then grip strength, back and leg strength, heart rate, flexibility, vital capacity, static balance, dynamic balance, and reaction time tests were performed. One (1) series, which included ten (10) shots was fired to determine the shooting success of the participants. There found a positive and high statistical significance between the scoresof the elite shooters in a series of shots and their expected vital capacity measurements (r=.656; p<0.05), between the scores of the junior shooters in a series of shots, their measured vital capacity (r=.820; p<0.01), their vital capacity percentage (r=.686; p<0.05), and their right-hand grip strength (r=.703; p<0.05). Furthermore, while a negative and high significance was acquired between the male participants’ scores in a series of shotsand the right foot dynamic balance (r= -790; p<0.05), there was a positive and high correlation between the scores of female participants in a series of shots and their expected vital capacity (r=.704; p<0.05). As a result, it was concluded that some performance parameters in terms of gender and level of competition affected the shooting performance of the participants.

Grip strength data for individuals with severe anorexia nervosa

Objective: This retrospective study compiled grip strength data of patients with severe anorexia nervosa to assess associations among grip strength, anorexia nervosa severity, depression, and physiological comorbidities. Design: 475 patients with severe anorexia nervosa admitted to an inpatient hospital and completed a grip strength assessment at admission and discharge. Depression was diagnosed via clinical interview. Independent sample t-tests and Mann-Whitney U tests compared difference in grip strength and anthropometric measures between anorexia nervosa subtypes. Linear and logistic regressions assessed associations among grip strength, depression, and physiological measures. Results: The cohort was 91.8% female (M age: 31.8 ± 11.7 years). At admission, patients had an average body mass index of 13.8 ± 2.4 kg/m2 with 97.7% exhibiting impaired right-hand grip strength for their sex and age. Weaker right grip strength was associated with admission lower body mass index, worsening bone mineral density z-scores, and lower serum prealbumin (all p’s<.05) for both sexes. Patients with binge-purge anorexia nervosa had significantly stronger right grip strength (M:19.0 ± 7.8 kg) compared to patients with restricting anorexia nervosa (M:16.9 ± 7.9 kg), p=0.003. Conclusion: Severe malnutrition from anorexia nervosa was associated with profound deficits in grip strength, medical comorbidities and disease severity, but was not associated with depression.

Correlation of Different Anthropometric Measurements of Hand and Grip Strength in the Adult Female Bangladeshi Garment Workers

Background: A reliable and valid measurement of hand anthropometry is important for designing dimensionally compatible hand tools, gloves and hand-held devices. Hand grip strength is accepted as an objective index for the functional integrity of upper extremity. The estimation of hand grip strength is of immense importance in determining the efficacy of different treatment strategies, treatment outcome and hand rehabilitation. The present study was planned to determine the various dimensions of hands, average hand grip strength of adult Bangladeshi female garment workers and the relationship between hand grip strength and different anthropometric measurements of hand. Material and Methods: Two hundred female garment workers of 20-25 years of age were selected by purposive non random sampling from five different garment factories of Dhaka and Narayangonj city. Different dimensions of both hands were measured directly with the help of digital slide caliper and flexible wire. Hand grip strength of both hands was measured by Smedley’s Hand Grip Strength Dynamometer. Result : Body height, weight, BMI, hand length and hand breadth of adult Bangladeshi garments workers showed positive correlation with hand grip strength, but only significant positive correlation was found between hand length and grip strength of right hand (r=+0.197, P<0.05) and left hand (r=+0.405, P<0.001). Conclusion: Significant positive correlation was found between hand anthropometry such as hand length, hand breadth and hand grip strength in adult Bangladeshi female garment workers. J Shaheed Suhrawardy Med Coll 2021; 13(2): 171-176

Correlation of mobile phone usage on grip strength, disabilities and posture in young adults

Background: The musculoskeletal issues are now common in excessive use of mobile phone for communication, gamming and socialization on internet. The excessive use of mobile phone may decrease the muscle strength and lead to poor posture ultimately functional impairment related to upper extremity. Objective: to determine correlation among duration of mobile phone usage, neck posture, disabilities and hand grip strength. Methods: A correlational cross sectional study was done at Riphah International University Lahore from March 2020 to February 2021. The target population was male and female young students of 18 to 24 years, used mobile phone more than 6 hours in a day. A total of n=400 subjectsarticipated in the study in which n=235 were females and n=165 were males. The information was gathered using the DASH Questionnaire to identify upper limb problems, the photogrammetry method to determine the cervical angle, and a dynamometer to determine the strength of each hand's grasp. The pearson product-moment correlation coefficient was done by using SPSS version 21. Result: The mean age of the study participant was 20.99±2.34 years. A total of n=165(41.25%) were male and remaining n=235 were female participated in the study. Increase use of mobile had negative significant small correlation with degree of cervical angle (p=0.04), right hand grip strength (p=0.01) and positive significant small correlation with DASH score (0.01). While no significant correlation between daily use of mobile phone and left hand grip strength Conclusion: The study concluded that as the duration of mobile phone usage increased, the forward head posture and disabilities of the upper limb also increased. But the grip strength of right hand decreased as the mobile phone duration is increased. Key words: Correlation, disabilities, female, grip strength, mobile phone, male, posture.

Effects of 12-week Tai Chi program on physical function, depression, and quality of life among cognitively impaired older adults: a feasibility study

BackgroundOlder adults with cognitive decline need physical activity for maintaining brain health and mitigating cognitive decline. Tai Chi is a safe and gentle aerobic exercise and has been recommended for people with various health conditions to improve their physical functioning, well-being, and quality of life (QoL). This study aimed to determine the feasibility of a 12-week program of Tai Chi for memory (TCM) among older adults with mild cognitive impairment (MCI) or dementia; and to determine the pilot effects of TCM on physical functioning, depression, and health-related QoL.MethodsA quasi-experimental design was used with two groups: MCI and dementia. The feasibility of the 12-week TCM program was assessed after it finished in terms of its acceptability, demand, implementation, practicality, adaptation, integration, expansion, and limited-efficacy testing. Other health-related outcomes, physical functioning, depression, and health-related QoL were measured before and after the TCM program. Outcome measures consist of a digital hand dynamometer for grip strength, the standard sit-and-reach test, the one-leg-standing balance test, timed up and go (TUG) test, the Korean version of the Geriatric Depression Scale, and the 12-item Short Form survey (SF-12). Paired and independent t-tests were used to compare the effects of TCM within and between groups.ResultsThe TCM program was completed by 41 participants with MCI (n = 21) or dementia (n = 20), and its accepted feasibility was assessed. After TCM, the MCI group exhibited significant enhancements in right-hand grip strength (t = − 2.13, p = .04) and physical-health-related QoL (t = − 2.27, p = .03). TUG scores improved in both groups (MCI, t = 3.96 p = .001; dementia, t = 2.54 p = .02). The adopted form of the TCM program was effectively and safely applied to those with various levels of cognitive impairment. The program was well accepted by the participants with a mean attendance rate of 87%. No adverse events were reported during the program.ConclusionTCM has the potential to improve physical functioning and QoL. Since there was no comparison group to control for confounding factors and low statistical power in the present study, further studies are warranted with a stronger design that includes longer follow-up periods. This protocol was retrospectively registered on Dec 1, 2022 (NCT05629650) at ClinicalTrials.gov.

Muscle Strength, Physical Fitness, Balance, and Walking Ability at Risk of Fall for Prefrail Older People.

This study was to explore the relationship of older adults' demographic information, physiological indices, and stages of frailty with their risk of falling. In the cross-sectional study, a total of 221 older adults with the mean age 74.9 (SD = 6.8) years old were surveyed by senior fitness test. Results were observed in terms of participants' physical fitness, with significant differences being observed in the correlations of left-hand grip strength (t = 5.05, p < .000), right-hand grip strength (t = 6.03, p < .000), and total grip strength (t = 5.70, p < .000), time up and go test (t = -6.25, p < .000), and 30-sec chair stand test (t = 7.19, p < .000) with the risk of falling. According to the logistic regression analysis results, long-term medication (OR = 0.12, 95% CI =0.02-0.62, p < .01) and right-hand grip strength (OR = 0.86, 95% CI =0.76-0.97, p < .01) are the main predictors of older adults' risk of falling. Older females with low education, history of falls, weaker grip strengths; taking longer to finish the TUG test; and standing fewer times during the 30-second chair stand test were at risk of fall. In prediction, older people using long-term medication were at lower risk of falling, and the greater the hand grip strength was, the lower the fall risk was. According to the research results, nursing personnel must develop care programs and improve older adults' risk of falls.

Plasma Metabolomics Reveals β-Glucan Improves Muscle Strength and Exercise Capacity in Athletes.

The present study aimed to assess the changes in muscle strength and plasma metabolites in athletes with β-glucan supplementation. A total of 29 athletes who met the inclusion criteria were recruited for this study (ChiCTR2200058091) and were randomly divided into a placebo group (n = 14) and β-glucan group (n = 15). During the trial, the experimental group received β-glucan supplementation (2 g/d β-glucan) for 4 weeks and the control group received an equal dose of placebo supplementation (0 g/d β-glucan), with both groups maintaining their regular diet and exercise habits during the trial. The athletes’ exercise performance, muscle strength, and plasma metabolome changes were analyzed after 4 weeks of β-glucan supplementation. The results showed a significant increase in mean grip strength (kg), right hand grip strength (kg), left triceps strength (kg), and upper limb muscle mass (kg) in the experimental group after the 4-week intervention compared to the preintervention period (p < 0.05). A comparison of the difference between the two groups after the intervention showed that there were significant differences between the control group and the experimental group in mean grip strength (kg) and right-hand grip strength (kg) (p < 0.05). Athletes in the experimental group showed significant improvements in 1 min double rocking jump (pcs), VO2max (ml/kg-min) (p < 0.05). The β-glucan intake increased the creatine-related pathway metabolites in plasma. Overall, these results suggest that 4 weeks of β-glucan supplementation can improve muscle strength in athletes, with the potential to increase aerobic endurance and enhance immune function, possibly by affecting creatine-related pathways.

The Effects of a Multicomponent Social Support Intervention on Physical Fitness and Exercise Attitude in Children: A 12-Week Randomized Controlled Trial.

Purpose: The current study is intended to assess the effects of a multicomponent social support intervention program on grip strength, sprinting, jumping, agility, flexibility, core strength and exercise attitude among children over a period of twelve weeks. Method: This study followed a randomized parallel design in which 366 children (age: 9.35 ± 1.12 years) in the 3rd–5th grade at an elementary school in China were allocated to an intervention group (n = 183) or a control group (n = 183). Participants were assessed twice (baseline and postintervention) for the following tests: (i) grip strength, (ii) 50 m dash, (iii) rope skipping, (iv) sit-ups, (v) sit-and-reach, and (vi) exercise attitude. The intervention group received the “Exercise Methods and Wellness Knowledge Guide (EMWKG)” leaflet three times a week. The control group was not required to make any changes. Results: Significant increases in pre–post left-hand grip strength (Cohen’s d = 0.10, p < 0.001), right-hand grip strength (Cohen’s d = 0.09, p < 0.001), and behavioral intention (Cohen’s d = 0.17, p < 0.01) were observed in the intervention group. Students in the control group showed significant decreases in three indicators: both 50 m (Cohen’s d = 0.19, p < 0.01) and sit-ups (Cohen’s d = 0.14, p < 0.05) as well as sit-and-reach (Cohen’s d = 0.46, p < 0.001). Significant differences (p < 0.001) were found between the two groups in right-hand grip strength (F = 7.109, ηp2 = 0.020), sit-and-reach (F = 11.255, ηp2 = 0.031), and subjective standards (F = 15.461, ηp2 = 0.043). A comparison of the post hoc test results showed that the intervention group scored 0.519 kg (95% CI: 0.136–0.901, Cohen’s d = 0.27), 0.944 cm (95% CI: 0.0391–1.497, Cohen’s d = 0.35), and 2.535 points (95% CI: 1.267–3.803, Cohen’s d = 0.41) higher than the control group in right-hand grip strength, sit-and-reach, and subjective standards, respectively. Conclusion: This combined social support theory-based intervention was effective in improving exercise attitude and fitness among children in 12 weeks.

Assessment of causal associations between handgrip strength and cardiovascular diseases: A two sample mendelian randomization study.

BackgroundSeveral observational studies have identified that handgrip strength was inversely associated with cardiovascular diseases (CVDs). Nevertheless, causality remains controversial. We conducted Mendelian randomization (MR) analysis to examine whether handgrip strength and risk of CVDs are causally associated.MethodsWe identified 160 independent single nucleotide polymorphisms (SNPs) for right-hand grip strength and 136 independent SNPs for left-hand grip strength at the genome-wide significant threshold (P < 5 × 10−8) from UK Biobank participants and evaluated these in relation to risk of CVDs. MR estimates was calculated using the inverse-variance weighted (IVW) method and multiple sensitivity analysis was further conducted.ResultsGenetical liability to handgrip strength was significantly associated with coronary artery disease (CAD) and myocardial infarction (MI), but not stroke, hypertension, or heart failure. Additionally, there was significant association between right-hand grip strength and atrial fibrillation (OR, 0.967; 95% CI, 0.950–0.984; p = 0.000222), however, suggestive significance was found between left-hand grip strength and atrial fibrillation (OR, 0.977; 95% CI, 0.957–0.998; p = 0.033). Results were similar in several sensitivity analysis.ConclusionOur study provides support at the genetic level that handgrip strength is negatively associated with the risk of CAD, MI, and atrial fibrillation. Specific handgrip strength interventions on CVDs warrant exploration as potential CVDs prevention measures.

Finger dexterity in well-functioning cohort of office workers in Macau.

The study aimed to describe the finger dexterity in office workers of an Asian population. One hundred twenty-seven right-handed office workers, aged 21-50 with a similar split of male and female, were recruited with finger dexterity measured by the O'Connor Finger Dexterity Test. The grip strength, tip and lateral pinch strength of both hands were also measured. This study provided the percentile score of the O'Connor Finger Dexterity Test of both males and females in the Asian population. Raw scores of below 218 and 213 seconds in male and female participants respectively reach the 90th percentile, and above 237 and 235 seconds in male and female below the 10th percentile. Results showed no significant difference in local mean scores across different age groups, between male and female and with varying hours of working in typing, filing, and writing. A significant difference was only found in finger dexterity and years of working as office workers. No significant correlation was found between the finger dexterity with grip strength, tip and lateral pinch of the dominant right hand. The results were similar to the original normative score with similar work skills and demands. The mean scores could be used as a valid reference for local occupational therapists to evaluate the finger dexterity of office workers. However, caution has to be taken that conclusions drawn can be biased because of the relatively small sample size, and the results cannot be generalized to represent a wider Asian population.

A bi-directional Mendelian randomization study of the sarcopenia-related traits and osteoporosis.

Both sarcopenia and osteoporosis are common geriatric diseases causing huge socioeconomic burdens, and clinically, they often occur simultaneously. Observational studies have found a controversial correlation between sarcopenia and osteoporosis and their causal relationship is not clear. Therefore, we performed a bi-directional two-sample Mendelian randomization (MR) analysis to assess the potential causal relationship between sarcopenia-related traits (hand grip strength, lean mass, walking pace) and osteoporosis. Our analysis was performed by applying genetic variants obtained from the UK Biobank and the GEnetic Factors for OSteoporosis (GEFOS) datasets. We used inverse-variance weighted (IVW) and several sensitivity analyses to estimate and cross-validate the potential causal relationship in this study. We found that bone mineral density (BMD) was causally positively associated with left-hand grip strength (β = 0.017, p-value = 0.001), fat-free mass (FFM; right leg FFM, β = 0.014, p-value = 0.003; left arm FFM, β = 0.014, p-value = 0.005), but not walking pace. Higher hand grip strength was potentially causally associated with increased LS-BMD (right-hand grip strength, β = 0.318, p-value = 0.001; left-hand grip strength, β = 0.358, p-value = 3.97 × 10–4). In conclusion, osteoporosis may be a risk factor for sarcopenia-related traits and muscle strength may have a site-specific effect on BMD.

Anthropometric characteristics, quality of life and functional capacity in adults living with HIV in Puerto Rico

Survival and longevity rates in people living with HIV (HIV+) have increased with the availability and use of antiretroviral therapy (ART). However, despite the above HIV+ adults treated with ART have a higher risk of developing dyslipidemia and high waist circumference. In addition, they have lower cardiorespiratory fitness, loss of muscle mass, reduced balance, and reduced functional capacity, which affects their quality of life. To explore the impact of balance perception, treadmill time, grip strength, body mass index (BMI), and waist-to-height ratio (WHtR) on quality of life in Latino Hispanic people living with HIV. This study recruited twenty-five participants from a community-based center, La Perla de Gran Precio, in San Juan, Puerto Rico, with the medical diagnosis of HIV. Descriptive measures were obtained for all variables of interest, and correlation and regression analyses were used to assess the associations between functional capacity, quality of life, and anthropometric measures. Result: Men had greater left- and right-hand grip strength than women (86.9±18.8, 56.9±26.8 kg; p=0.003 and 87.6±15.1 vs. 61.4±26.6 kg; p =0.004). Two anthropometric variables showed a trend toward a moderate positive correlation with quality of life: WHtR (r= -0.38, p =0.12) and BMI (r= -0.38, p = p-0.14). Although gender differences in upper body strength are expected, handgrip strength is within the gender-specific average range of the general population. The integration of anthropometric characteristics and upper body strength when prescribing exercise must be considered since these factors influence functional capacity and quality of life among HIV+ adults.

Health-related physical fitness among adolescent schoolgirls in Madinah city, western Saudi Arabia

In Saudi Arabia, health-related physical fitness components in girls have received far less attention than physical activity. Therefore, the aim of this study was to assess health-related physical fitness components (cardiorespiratory fitness, body fat, muscle strength, and flexibility) among adolescent schoolgirls in Madinah city, western Saudi Arabia. Thirty-six female students (mean ± standard deviation, age, 17.4 ± 1.3 years; body mass, 51.6 ± 11.1 kg; height, 154.5 ± 6.9 cm) performed a Queen’s College Step Test to estimate maximal oxygen consumption. Body fat percentage was determined using a bioelectrical impedance analyzer. Hand grip strength was measured using a hand grip dynamometer, and flexibility was determined by using the sit and reach test. The mean (±standard deviation) of estimated maximal oxygen consumption was 39.5 ± 6.3 (ml.kg.min). The mean (±standard deviation) of Body fat percentage, right-hand grip strength, left-hand grip strength, and flexibility were 31.0 ±9.0 (%), 16.5±5.5 (kg), 17.1 ±4.9 (kg), and 10.6±4.8 (cm), respectively. We conclude that multiple health-related physical fitness components—with the exception of cardiorespiratory fitness—should be targeted, particularly body composition, muscle strength, and flexibility, to enhance health status among Saudi adolescent schoolgirls in Madinah. This may be accomplished by local schools, which should offer exercise programs to improve students’ physical fitness components.

Health-related physical fitness among adolescent school boys in Madinah city, western Saudi Arabia

This study aimed to measure health-related physical fitness components (cardiorespiratory fitness, body fat, muscle strength, flexibility) among adolescent school boys in Madinah, western Saudi Arabia. The participants comprised 36 male students who performed a maximal multistage 20-m shuttle run test to estimate maximal oxygen consumption (VO2max). Body fat percentage (BF%) was determined using the bioelectrical impedance scale; hand grip strength was measured using a hand grip dynamometer; and flexibility was determined using the sit and reach test. The results of the health-related physical fitness tests reveal that the mean (± SD) value of estimated VO2max was 41.1 ± 6.9 (ml.kg.min). The mean (± SD) values of BF%, right-hand grip strength, left-hand grip strength, and flexibility were 18.7 ± 8.6 (%), 33.3 ± 5.6 (kg), 32.8 ± 5.7 (kg), and 15.8 ± 3.9 (cm), respectively. With the exception of flexibility, we conclude that it is necessary to improve health-related physical fitness components, particularly muscle strength, among Saudi adolescent school boys in Madinah city.

Effect of Cross-Sex Hormones on Body Composition, Bone Mineral Density, and Muscle Strength in Trans Women.

BackgroundCross-sex hormone therapy (CHT) changes the physical characteristics of transgender women to match their gender identity and expression. This study aimed to determine the effects of feminizing cross-sex hormones on body composition, bone mineral density (BMD) and muscle strength in transgender women.MethodsA prospective observational study assessed 11 participants who underwent feminizing CHT. Dual energy X-ray absorptiometry (DXA), and handgrip strength were measured before CHT and after 6-months of CHT. Fat mass, lean body mass (LBM), and BMD were measured by DXA and handgrip strength was measured by hand-dynamometer.ResultsRegional body fat in the trunk, legs, and gynoid region increased by 18%, 27.4%, and 27.2%, respectively after 6 months of CHT. Total body fat increased by 16.2%, while the fat mass ratio decreased by 7.2%. Although body fat increased, the android/gynoid fat ratio decreased; BMD in the lumbar spine significantly increased by 3.9% (P=0.0051), but changes in the femoral neck (P=0.1969) and total femur (P=0.4769) were not significant. Changes in LBM ranged from −3% (trunk) to −8% (arm region). Right-hand grip strength also significantly decreased by 7.7% (P=0.0467).ConclusionsAfter 6 months of CHT, transgender women showed a general increase in fat mass and a decreased in overall LBM and handgrip strength. Increase in fat mass percentage were more remarkable in gynoid region, leading to a more “female” body fat distribution.

Acute effects of myofascial release and static stretching on handgrip strength in jiu-jitsu fighters

This study aimed to compare the techniques of myofascial release and static stretching on the handgrip strength of jiu-jitsu fighters. Ten jiu-jitsu athletes (age 29.9 ± 7.4 years; height 1.74 ± 0.06 m; body mass 77.50 ± 9.89 kg; BMI 25.63 ± 2.13 kg/m2) from an academy in the Lagos Region, RJ, Brazil, participated in this study. Left handgrip strength (LHS) and right handgrip strength (RHS) were analyzed through a dynamometer. Participants underwent manual myofascial release, myofascial release with suction cups, and maximum static stretching. The techniques were applied in three days with an interval of 1 week each, with random drawing, on the day of the intervention. No significant differences were found between the measurements of the dynamometry values after the manual myofascial release and myofascial release with suction cups; however, the handgrip measures concerning the static stretching were reduced (LHS: p < 0.001; RHS: p = 0.002). It was observed that the technique of maximum static stretching showed a significant reduction in the left handgrip strength (Δ% LHS) when compared to the manual myofascial release (p = 0.004) and the myofascial release with suction cups (p = 0.049). There were no significant differences between the myofascial release techniques. Myofascial release did not affect handgrip strength. However, the use of maximum static stretching showed a reduction in handgrip strength in the non-dominant hand of the jiu-jitsu fighters.

Supplementation of Kaempferia parviflora Extract Enhances Physical Fitness and Modulates Parameters of Heart Rate Variability in Adolescent Student-Athletes: A Randomized, Double-Blind, Placebo-Controlled Clinical Study

This randomized double-blind controlled study aimed to investigate the effects of a standardized Kaempferia parviflora (KP) extract on the physical fitness and heart rate variability (HRV) parameters in adolescent sport school students. 194 male students were recruited and randomized into two groups (n = 97), matched by age and sports. The KP-treated group received KP extract capsules at a dose of 360 mg/day and the control group received placebo capsules, continuously for 12 weeks. Physical fitness performance and HRV parameters were monitored with blood biochemical analysis for product safety. KP extract significantly increased the right-hand grip strength, the back-leg strength and maximal oxygen consumption (VO2 max) and decreased the time used for 50-meter sprint test without changing the sit-and-reach test and the 40 yard technical test. For HRV parameters, KP extract significantly increased standard deviation of normal to normal intervals (SDNN), square root of the mean of square of successive normal to normal interval differences (RMSSD) and high frequency (HF) norm, without changing low frequency (LF) norm and LF/HF ratio. The increase in stress resistance and decrease in stress index were found in the KP-treated group, without changing the autonomic nervous system (ANS) activity and balance. Blood biochemical analysis showed normal values of all participants. This data indicates the safety and positive effects of KP on muscle strength, endurance and speed, but not on the flexibility and agility. The modulatory effects of KP extract on HRV parameters suggest its anti-stress effects and would encourage the application in a sport training and exercise.