Comparison of Dual-Energy X-ray Absorptiometry (DXA) Versus a Multi-Frequency Bioelectrical Impedance (InBody 770) Device for Body Composition Assessment after a 4-Week Hypoenergetic Diet

Timing, velocity, and magnitude of pubertal changes in body composition: a longitudinal study

BACKGROUND

Pubertal changes in body composition significantly influence future health, with links to various diseases. This study aimed to evaluate the weight changes, fat-free mass (FFM), and body fat mass (BFM) during pubertal growth in Korean children and adolescents.

METHODS

We utilized mixed longitudinal data, employing bioelectrical impedance analysis for 4641 height measurements (2204 boys, 2437 girls) from 361 individuals (170 boys, 191 girls) aged 7-18 years. Utilizing the Superimposition by Translation and Rotation (SITAR) model, a shape-invariant growth curve model, reference curves for height, weight, and body composition change velocities were estimated.

RESULTS

Korean boys experience peak weight velocity (PWV) at an average age of 12.41 years, with a rate of 8.19 kg/year, peak fat-free mass velocity (PFFV) at 12.70 years (7.60 kg/year), and peak body fat mass velocity (PBFV) at 9.69 years (2.67 kg/year). Korean girls show PWV at 11.28 years (6.33 kg/year), PFFV at 11.13 years (4.86 kg/year), and PBFV at 12.33 years (2.72 kg/year). Positive correlations exist among the ages of peak height velocity, PWV, PFFV, and PBFV.

CONCLUSIONS

This research represents the groundbreaking application of the SITAR model in analyzing changes in body composition during pubertal growth in Korean children and adolescents.

IMPACT

This study utilized the SITAR model to analyze longitudinal changes in the body composition of the general pediatric population in Korea across pre- and post-pubertal stages, addressing overlooked aspects in cross-sectional studies. Examining growth parameters, including size (mean mass), tempo (timing), and velocity (compression and expansion) for each body component, revealed positive correlations among ages at peak velocities for various body composition parameters. This study can be employed for further investigations that compare the tempo, size, and velocity of various body composition parameters in pediatric disease cohorts and the general population.

Reliability and Agreement Assessment of Sarcopenia Diagnosis through Comparison of Bioelectrical Impedance Analysis and Dual-Energy X-ray Absorptiometry

A unified diagnostic criterion has yet to be established for sarcopenia. Therefore, we analyzed the reliability and validity of sarcopenia diagnosis using bioelectrical impedance analysis (BIA) compared with the gold standard, dual-energy X-ray absorptiometry (DEXA), and evaluated the predictive accuracy of BIA for diagnosis. The clinical trial, involving a total of 239 participants, was conducted between December 2018 and September 2019 on healthy volunteers without significant medical histories. The participants underwent health assessments, followed by sequential DEXA and BIA measurements. In both the low and normal appendicular skeletal muscle (ASM) groups, there were significant differences in the right arm, left arm, right leg, left leg, ASM, and ASM index (ASMI) between DEXA and BIA across all age groups (p < 0.05). BIA tended to overestimate compared to DEXA, but ASMI values for males and females were consistent with the criteria for sarcopenia. Bland-Altman analysis showed that each segment in both the low and normal ASM groups fell within the limits of agreement (LOA). The diagnosis of sarcopenia using BIA was significantly different from that using DEXA. However, it exhibited a significantly high correlation, fell within the LOA, and demonstrated high predictive accuracy. BIA can be considered an effective tool for diagnosing sarcopenia.

Effects of male paratroopers' initial body composition on changes in physical performance and recovery during a 20-day winter military field training

Changes in physiological markers and physical performance in relation to paratroopers' initial body composition were investigated during a 20-day winter military field training (MFT) and the subsequent 10-day recovery period. Body composition, serum hormone concentrations and enzymatic biomarkers, and physical performance of 58 soldiers were measured before, during, and after MFT. Comparisons were done according to soldiers' body fat percentage before MFT between low-fat (<12% body fat) and high-fat (>12% body fat) groups. Correlations between body fat percentage preceding MFT and changes in muscle mass, physical performance, and serum hormone concentrations and enzymatic biomarkers were investigated. It was hypothesized that soldiers with a higher fat percentage would have smaller decrements in muscle mass, physical performance, and serum testosterone concentration. The change in muscle and fat mass was different between groups (p < 0.001) as the low-fat group lost 0.8 kg of muscle mass and 2.0 kg of fat mass, while there was no change in muscle mass and a loss of 3.7 kg of fat mass in the high-fat group during MFT. Fat percentage before MFT correlated with the changes in muscle mass (R2 = 0.26, p < 0.001), serum testosterone concentration (R2 = 0.22, p < 0.001), and evacuation test time (R2 = 0.10, p < 0.05) during MFT. The change in muscle mass was correlated with the changes in evacuation test time (R2 = 0.11, p < 0.05) and countermovement jump test results (R2 = 0.13, p < 0.01) during MFT. Soldiers with a higher initial fat percentage lost less muscle mass, and had smaller decrements in some aspects of physical performance, as well as in serum testosterone concentration during MFT.

Fat and fat-free mass measurement agreement by dual-energy X-ray absorptiometry versus bioelectrical impedance analysis: Effects of posture and waist circumference

Background

Bioelectrical impedance analysis (BIA) operates under the assumption that the conductor has a uniform cylindrical shape. However, this assumption may be violated if measures are taken in the seated position, especially in people with a high waist circumference (WC).

Aims

The aims of this research were to determine whether posture (supine, standing, and seated) and WC affect agreement between BIA and dual-energy X-ray absorptiometry (DXA) measures of fat mass (FM) and fat-free mass (FFM).

Materials & Methods

Baseline data were collected from 28 adults (mean = 61.4 ± 6.9 years, 64.3% female) with obesity (BMI 38.6 ± 5.0 kg/m2). Body composition was measured using BIA in the supine, standing, and seated positions and by DXA while supine. Intraclass correlation coefficient (ICC) analyses with two-way mixed effects and absolute agreement were performed to determine agreement.

Results

Point estimates were excellent for FM and FFM while supine, excellent for FM and good for FFM while standing, and moderate for FM and good for FFM while seated. BIA measures in the supine position resulted in the narrowest 95% confidence intervals compared with other positions. Better agreement was observed across all positions in participants with a WC below the median (118.3 cm).

Discussion

Despite the potential pragmatic value of measuring with BIA in a seated position, the results of this analysis demonstrate the poorest agreement between DXA and BIA methods, especially in individuals with high WC.

Conclusion

Findings from this study demonstrate that BIA, particularly when measured in a supine position, can serve as a viable alternative to DXA for measuring body composition in people with obesity.

Impact of cold exposure on life satisfaction and physical composition of soldiers

This article has been retracted.

The Association of Isocaloric Substitution of Dietary Protein in Middle Age with Muscle Mass and Strength in Old Age: The Hordaland Health Study

Background

Age-associated loss of muscle mass and strength is an important predictor of disability in older persons. Although several mechanisms contribute to the decline in muscle mass and function seen with aging, the process is thought to be accelerated by an inadequate protein intake. However, the optimal amount and source of protein and the role of dietary protein intake over the life course remain uncertain.

Objectives

In a sample of community-dwelling adults in Western Norway, the current study examined both cross-sectional and longitudinal associations over 20 y of dietary protein intake with appendicular skeletal muscle mass (ASMM) and muscle strength measured by handgrip strength (HGS) in older age.

Methods

Dietary intake was assessed using food frequency questionnaires (FFQs) in middle age (46-49 y) and older age (67-70 y) within the community-based Hordaland Health Study.

Results

Adjusted, multivariate linear regression analyses revealed a negative cross-sectional association between the substitution of total protein (TP) and animal protein (AP), with fat and carbohydrates, on ASMM in women but not in men. No longitudinal associations were found between substitution of dietary protein intake and ASMM in either sex in adjusted models. Similarly, no cross-sectional or longitudinal associations were evident between substitution of dietary protein intake and HGS in either sex in adjusted models.

Conclusion

The findings in the current study highlight the need to clarify the role of dietary protein intake in the maintenance of muscle mass and muscle strength in healthy older adults.

Development of an interpretable machine learning-based intelligent system of exercise prescription for cardio-oncology preventive care: A study protocol

Background

Cardiovascular disease (CVD) and cancer are the first and second causes of death in over 130 countries across the world. They are also among the top three causes in almost 180 countries worldwide. Cardiovascular complications are often noticed in cancer patients, with nearly 20% exhibiting cardiovascular comorbidities. Physical exercise may be helpful for cancer survivors and people living with cancer (PLWC), as it prevents relapses, CVD, and cardiotoxicity. Therefore, it is beneficial to recommend exercise as part of cardio-oncology preventive care.

Objective

With the progress of deep learning algorithms and the improvement of big data processing techniques, artificial intelligence (AI) has gradually become popular in the fields of medicine and healthcare. In the context of the shortage of medical resources in China, it is of great significance to adopt AI and machine learning methods for prescription recommendations. This study aims to develop an interpretable machine learning-based intelligent system of exercise prescription for cardio-oncology preventive care, and this paper presents the study protocol.

Methods

This will be a retrospective machine learning modeling cohort study with interventional methods (i.e., exercise prescription). We will recruit PLWC participants at baseline (from 1 January 2025 to 31 December 2026) and follow up over several years (from 1 January 2027 to 31 December 2028). Specifically, participants will be eligible if they are (1) PLWC in Stage I or cancer survivors from Stage I; (2) aged between 18 and 55 years; (3) interested in physical exercise for rehabilitation; (4) willing to wear smart sensors/watches; (5) assessed by doctors as suitable for exercise interventions. At baseline, clinical exercise physiologist certificated by the joint training program (from 1 January 2023 to 31 December 2024) of American College of Sports Medicine and Chinese Association of Sports Medicine will recommend exercise prescription to each participant. During the follow-up, effective exercise prescription will be determined by assessing the CVD status of the participants.

Expected outcomes

This study aims to develop not only an interpretable machine learning model to recommend exercise prescription but also an intelligent system of exercise prescription for precision cardio-oncology preventive care.

Ethics

This study is approved by Human Experimental Ethics Inspection of Guangzhou Sport University.

Clinical trial registration

http://www.chictr.org.cn, identifier ChiCTR2300077887.

Physiological and physical performance changes during a 20-day winter military training course and its subsequent 10-day recovery period

The present study investigated physiological, mental and physical performance changes during a 20-day winter military training course and the following 10-day recovery period. Fifty-eight (age 19 ± 1 years, height 182 ± 6 cm, body mass 78.5 ± 7.2 kg) male soldiers volunteered. Body composition, serum biomarker levels and performance tests were measured four times during the study. In addition, questionnaires were collected daily for subjective stress and rate of perceived exertion. The course induced significant declines in body (-3.9%, p < 0.05) and fat mass (-31.6%, p < 0.05) as well as in all assessed physical performance variables (-9.2 - -20.2%, p < 0.05), testosterone (-73.7%, p < 0.001) and IGF-1 concentrations (-43.6%, p < 0.001). At the same time, the sex hormone-binding globulin, creatine kinase, and C-reactive protein values increased significantly (46.3-1952.7%, p < 0.05). After the 10-day recovery period, the body composition and hormonal values returned to the baseline (p < 0.05), as did some physical performance variables, such as 2 min sit-ups and the evacuation test (p < 0.05). However, explosive force production in the upper and lower bodies remained unrecovered. The 20-day winter military training caused significant physiological and mental stress, as well as a drastic decline in physical performance even for highly physically fit soldiers, and the 10-day recovery period did not establish full recovery.

Substantial Loss of Skeletal Muscle Mass Occurs After Femoral Fragility Fracture

BACKGROUND

Femoral fragility fractures in older adults can result in devastating loss of physical function and independence. Skeletal muscle atrophy likely contributes to disability. The purpose of this study was to characterize the change in skeletal muscle mass, investigate the relationship with malnutrition and physical function, and identify risk factors for skeletal muscle loss.

METHODS

Adults ≥65 years of age who were treated with operative fixation of an isolated femoral fragility fracture were enrolled in this multicenter, prospective observational study. Skeletal muscle mass was assessed within 72 hours of admission using multifrequency bioelectrical impedance analysis, which was repeated at 6 weeks, 3 months, and 6 months. Sarcopenia was defined by sex-specific cutoffs for the appendicular skeletal muscle mass index. The Mini Nutritional Assessment was used to measure nutritional status at the time of injury. Physical function was measured using the Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function domain. Linear mixed models were used to evaluate changes in skeletal muscle mass and PROMIS Physical Function scores over time and to evaluate factors associated with skeletal muscle mass changes.

RESULTS

Ninety participants (74% female) with a mean age of 77.6 ± 9.0 years were enrolled. At the time of injury, 30 (33%) were sarcopenic and 44 (49%) were at risk for malnutrition or had malnutrition. Older age was associated with lower skeletal muscle mass (age of ≥75 versus <75 years: least squares mean [and standard error], -3.3 ± 1.6 kg; p = 0.042). From the time of injury to 6 weeks, participants lost an average of 2.4 kg (9%) of skeletal muscle mass (95% confidence interval [CI] = ‒3.0 to ‒1.8 kg; p < 0.001). This early loss did not recover by 6 months (1.8 kg persistent loss compared with baseline [95% CI = ‒2.5 to ‒1.1 kg]; p < 0.001). Participants with normal nutritional status lost more skeletal muscle mass from baseline to 6 weeks after injury compared with those with malnutrition (1.3 kg more loss [standard error, 0.6 kg]; p = 0.036). A 1-kg decrease in skeletal muscle mass was associated with an 8-point decrease in the PROMIS Physical Function (model parameter estimate, 0.12 [standard error, 0.04]; p = 0.002).

CONCLUSIONS

We found that older adults with femoral fragility fractures lost substantial skeletal muscle mass and physical function. Participants with adequate baseline nutrition actually lost more muscle mass than those who were malnourished, indicating that future investigations of interventions to prevent muscle loss should focus on older adults regardless of nutritional status.

LEVEL OF EVIDENCE

Prognostic Level II . See Instructions for Authors for a complete description of levels of evidence.

Association between total body muscle percentage and prevalence of non-alcoholic fatty liver disease in Korean adults findings from an 18-year follow-up: a prospective cohort study

BACKGROUND

This study aimed to elucidate the association between total lean muscle mass and the incidence of non-alcoholic fatty liver disease (NAFLD) in the adult Korean population.

METHODS

Utilizing data derived from the 18-year prospective cohort of the Korean Genome and Epidemiology Study, NAFLD was diagnosed via the hepatic steatosis index with an established cutoff value of 36. Lean muscle mass was assessed via bioelectrical impedance analysis and subsequently divided into tertiles. A generalized mixed model with a logit link was employed for repeated measures data analysis, accounting for potential confounders.

RESULTS

Analysis encompassed 7,794 participants yielding 49,177 measurements. The findings revealed a markedly increased incidence of NAFLD in the lower tertiles of muscle mass, specifically, tertile 1 (odds ratio [OR], 20.65; 95% confidence interval [CI], 9.66-44.11) and tertile 2 (OR, 4.57; 95% CI, 2.11-9.91), in comparison to tertile 3. Age-dependent decreases in the OR were observed within the tertile 1 group, with ORs of 10.12 at age of 40 years and 4.96 at age of 80 years. Moreover, each 1%-point increment in total muscle mass corresponded with an estimated OR of 0.87 (95% CI, 0.82-0.93) for NAFLD resolution.

CONCLUSIONS

The study demonstrates a significant association between total muscle mass and NAFLD prevalence among Korean adults. Given the potential endocrine role of muscle mass in NAFLD pathogenesis, interventions aimed at enhancing muscle mass might serve as an effective public health strategy for mitigating NAFLD prevalence.

The effect of acute hydration on body composition assessed by multi-frequency and single-frequency bioelectrical impedance

BACKGROUND

Multi-frequency bioelectrical impedance (MF-BIA) provides an estimate of total body water. However, it is unknown if MF-BIA detects body water increases due to acute hydration, thus affecting the validity of MF-BIA body composition measurements. The purpose of this study was to compare the effects of pre-testing fluid ingestion on body composition estimation using single-frequency bioelectrical impedance (SF-BIA) and MF-BIA.

METHODS

Thirty-nine subjects (20 male, 19 female) were tested for body composition using DXA, SF-BIA and MF-BIA before and after consumption of 2 L of water.

RESULTS

Hydration significantly increased fat percentage in men and women for MF-BIA (+2.1±0.7% for men, +2.6±0.7% for women) and SF-BIA (+1.3±0.7% for men, +2.1±0.9% for women). Additionally, hydration significantly increased fat-free mass (FFM) for DXA (+1.4±0.8 kg for men, +1.7±0.4 kg for women) and SF-BIA (+0.5±0.6 kg) in men. Hydration significantly increased fat mass (FM) for all modes (DXA +0.3±0.3 kg, MF-BIA +2.0±0.7 kg, SF-BIA +1.3±0.6 kg) in males, and only for MF-BIA (+2.2±0.3 kg) and SF-BIA (+1.7±0.5 kg) in females. Increases in FM were highest for MF-BIA for both males and females. Total body water was unchanged in males and significantly decreased with acute hydration in females.

CONCLUSIONS

MF-BIA improperly categorizes increased mass due to acute hydration as fat mass, resulting in an increase in measured body fat percentage. These findings confirm the need to standardize hydration status for body composition measurements using MF-BIA.

The association of dietary patterns with muscle mass and strength in old age: The Hordaland Health Study

PURPOSE

The single nutrient approach in nutrition research lacks the ability to account for synergistic relationships between dietary components. Current evidence suggests that diet quality, reflecting overall dietary intake, may influence muscle health. In a community-based observational study in Western Norway, we examined dietary patterns in relation to muscle mass and strength at age 67-70.

METHODS

The current analysis was conducted in men and women of The Hordaland Health Study (HUSK), who participated in both the second (HUSK2) and third study wave (HUSK3). Dietary patterns were extracted by principal component analysis (PCA) on food frequency questionnaire (FFQ) data. Individual dietary pattern scores (DPS) for HUSK2 (age 46-49) and HUSK3 (age 67-70), and overall DPS (oDPS) were calculated. Outcome variables were appendicular skeletal muscle mass (ASMM) and handgrip strength (HGS) measured in HUSK3. The relationships of HUSK3 DPS and oDPS with ASMM and HGS were assessed by multivariate linear regression analysis adjusted for potential confounding factors.

RESULTS

We identified three distinct dietary patterns, labelled 'Western', 'Healthy', and 'Sweets-focused'. A significant positive association was observed between the oDPS for the 'Healthy' dietary pattern and ASMM in both men and women at age 67-70. No significant associations were found between HUSK3 DPS or oDPS for any of the identified dietary patterns and HGS in our population.

CONCLUSION

Higher oDPS on a dietary pattern predominantly rich in fish, vegetables, nuts and seeds, fruit and berries, and eggs was associated with better ASMM at age 67-70. To establish the influence of diet quality on muscle health, further long-term studies with repeated dietary assessments are warranted.

Agreement Between Dual-Energy X-ray Absorptiometry and Bioelectric Impedance Analysis for Assessing Body Composition in Athletes: A Systematic Review and Meta-Analysis

OBJECTIVE

To compare dual-energy x-ray absorptiometry (DXA) and bioelectric impedance analysis (BIA) in the assessment of body composition in athletes.

DATA SOURCES

A systematic review and meta-analysis was conducted collating peer-reviewed studies that compared BIA with DXA for the assessment of body composition in athletes that indexed in MEDLINE, CINAHL, EMBASE, and PsycINFO databases.

MAIN RESULTS

After duplicate removal, 267 articles remained for full-text screening. Sixty-three studies remained for the final inclusion, with 8 focused on athletes (n = 461). Five studies were included in the meta-analysis and were rated as positive after risk of bias assessment, whereas the remaining were neutral. BIA overestimated fat-free mass (FFM) over DXA 2.78 (1.38-4.18) (mean difference ± 95% CI) with an effect size of 3.9( P < 0.001).

CONCLUSIONS

BIA was found to overestimate total FFM when compared with DXA. Correlations are high between BIA and DXA; however, the limits of agreement are wide. Hence, BIA may not be a suitable substitute for DXA body composition scanning of athletes. Because of the low level of ionizing radiation exposure, the use of DXA should always be medically justified, and therefore, it is not recommended for repeat, longitudinal measurements in healthy subjects.We recommend that clinicians do not use BIA interchangeably with DXA in the assessment of body composition in athletes. Considerations should be made over the safety and appropriateness of DXA in young healthy adults. For long-term use, BIA can be warranted for athletes.PROSPERO Registration Number: CRD42020183777.

Male Army ROTC Cadets Fail to Meet Military Dietary Reference Intakes and Exhibit a High Prevalence of Low Energy Availability and Poor Sleep Quality

The purpose of this study was to assess the dietary habits, prevalence of low energy availability (EA), and sleep quality in a cohort of male army Reserve Officer Training Corps (ROTC) cadets, and to investigate the relationship between EA and sleep quality as well as EA and various body composition variables that are important for tactical readiness. Thirteen male army ROTC cadets (22.2 ± 4.1 yrs; BMI: 26.1 ± 2.3) had their EA and body composition assessed using diet and exercise records alongside bioelectrical impedance analysis. Cadets also completed a validated sleep questionnaire. Sixty-two percent of participants presented with clinically low EA (<30 kcal/kg fat-free mass [FFM]) and none met the optimum EA threshold (≥45 kcal/kg FFM). Dietary analysis indicated that 15%, 23%, 46%, 23%, and 7% of cadets met the Military Dietary Reference Intakes (MDRI) for calories, carbohydrates, protein, fat, and fiber, respectively. Additionally, 85% of cadets exhibited poor sleep quality. Significant associations between EA and fat mass/percent body fat were shown (p < 0.05). There was, however, no statistically significant correlation between EA and sleep quality. The present study found a high prevalence of low EA and sleep disturbance among male army ROTC cadets and that many were unable to meet the MDRIs for energy and macronutrient intake. Further, low EA was associated with higher percent body fat and fat mass but not sleep quality.

Clinic and Home-Based Exercise with Blood Flow Restriction Resolves Thigh Muscle Atrophy after Anterior Cruciate Ligament Reconstruction with the Bone-Patellar Tendon-Bone Autograft: A Case Report

Anterior cruciate ligament reconstruction (ACLR) results in thigh muscle atrophy. Of the various interventions proposed to mitigate thigh muscle atrophy, exercise with blood flow restriction (BFR) appears safe and effective. Some literature suggests daily exposure to exercise with BFR may be indicated during the early phase of ACLR rehabilitation; this case report outlines the methodology utilized to prescribe clinic- and home-based BFR within an outpatient rehabilitation program. A 15-year-old male soccer player suffered a left knee injury involving the anterior cruciate ligament and both menisci. He underwent ACLR and completed exercise with BFR as part of his clinic- and home-based rehabilitation program, which included practical blood flow restriction during home-based rehabilitation. After 16 weeks of rehabilitation, surgical limb thigh girth values were objectively larger than the non-surgical limb (surgical, 52.25 cm; non-surgical 50 cm), as well as the multi-frequency bioelectrical impedance analysis of his lower-extremity lean body mass (surgical limb, 10.37 kg; non-surgical limb, 10.02 kg). The findings of this case report suggest that the inclusion of clinic- and home-based BFR within an outpatient rehabilitation program may be indicated to resolve thigh muscle atrophy early after ACLR.

Comparisons of Two Bioelectrical Impedance Devices and Manual versus Sensor-Based Short Physical Performance Batteries for Assessment of Muscle Mass and Physical Performance

The assessment of muscle mass and physical performance is essential for the diagnosis of sarcopenia. This study examined the validity of bioimpedance analysis (BIA) and a sensor-based short physical performance battery (SPPB) device for analyzing appendicular skeletal muscle mass (ASM) and physical performance. Forty-one older adults were measured for ASM and physical performance with two BIA devices (InBody770 vs. T-SCAN PLUS III) and two SPPB devices (manual mSPPB vs. sensor-based sSPPB). Validity statistics included the intraclass correlation coefficient (ICC) and Bland-Altman plots to examine the agreement of data from the BIA (InBody770 vs. T-SCAN PLUS III) and the SPPBs (mSPPB vs. sSPPB). There was a significant ICC for skeletal muscle mass between the T-SCAN PLUS III and InBody770 devices (ICC = 0.8822; p < 0.0001). The mSPPB and sSPPB values showed agreement across all components: 0.8654 for the total scores, 0.8879 for the walking speed, 0.8889 for the chair stand, and 0.6863 for the standing balance. No systemic bias was observed between the two methods for the BIA and SPPB devices. Measurements using the T-SCAN PLUS III and sSPPB seem to be highly correlated with the InBody770 and mSPPB devices in older adults and may be valid for assessing muscle mass and physical performance.

Pre-Season Nutritional Intake and Prevalence of Low Energy Availability in NCAA Division III Collegiate Swimmers

There is limited information regarding the dietary habits and energy availability (EA) of collegiate athletes. Therefore, the purpose of the present study is to assess the nutrient intakes, dietary habits, and prevalence of low EA (<30 kcals/kg FFM) in a group of National Collegiate Athletic Association (NCAA) Division III male and female swimmers. Energy and nutrient intake, body composition, and exercise energy expenditure was assessed in 30 (n = 15 males, n = 15 females) NCAA Division III swimmers during pre-season using three-day diet and seven-day activity records alongside multi-frequency, bioelectric impedance analysis. A validated screening tool was used to assess for low EA in the female swimmers. Mean EA in male and female athletes was 32.7 ± 12 and 34.9 ± 13.7 kcals/kg FFM, respectively, and was not significantly different between the sexes (p = 0.65). Twenty percent of swimmers (n = 3 males, n = 3 females) presented with optimal EA, 37% (n = 5 males, n = 6 females) presented with sub-optimal EA, and 43% (n = 7 males, n = 6 females) presented with low EA. Swimmers who presented with a low EA consumed significantly less calories, carbohydrates, and proteins than non-low EA swimmers (p < 0.02). The validated screening tool failed to classify 50% of female swimmers who presented with low EA. Only eight athletes achieved the USDA MyPlate recommendation for fruits, whereas three athletes achieved the recommendation for vegetables, with no differences between the sexes (p > 0.05). The present findings show that there was a high prevalence of low EA during the pre-season among male and female collegiate swimmers that was not fully captured using a validated screening tool for females. Low EA occurred alongside lower intakes of calories, carbohydrates, and proteins, and the majority of swimmers did not meet the United States Department of Agriculture recommendations for fruit and vegetable intake. These data stress the need for improved dietary intakes in NCAA Division III collegiate swimmers.

Development and validation of a prediction equation for body fat percentage from measured BMI: a supervised machine learning approach

Body mass index is a widely used but poor predictor of adiposity in populations with excessive fat-free mass. Rigorous predictive models validated specifically in a nationally representative sample of the US population and that could be used for calibration purposes are needed. The objective of this study was to develop and validate prediction equations of body fat percentage obtained from Dual Energy X-ray Absorptiometry using body mass index (BMI) and socio-demographics. We used the National Health and Nutrition Examination Survey (NHANES) data from 5931 and 2340 adults aged 20 to 69 in 1999-2002 and 2003-2006, respectively. A supervised machine learning using ordinary least squares and a validation set approach were used to develop and select best models based on R² and root mean square error. We compared our findings with other published models and utilized our best models to assess the amount of bias in the association between predicted body fat and elevated low-density lipoprotein (LDL). Three models included BMI, BMI², age, gender, education, income, and interaction terms and produced R-squared values of 0.87 and yielded the smallest standard errors of estimation. The amount of bias in the association between predicted BF% and elevated LDL from our best model was -0.005. Our models provided strong predictive abilities and low bias compared to most published models. Its strengths rely on its simplicity and its ease of use in low-resource settings.

The impact of high intensity interval training on serum omentin-1 levels, lipid profile, and insulin resistance in obese men with type 2 diabetes mellitus

BACKGROUND: High-intensity interval training (HIIT) is an effective exercise method that could lead to favorable changes in obese and diabetic subjects. OBJECTIVE: To investigate the effects of HIIT on serum omentin-1 levels, lipid profile, and insulin resistance in diabetic obese men. METHODS: Fifty obese men suffering from T2DM with ages between 40 and 60 years were enrolled. Subjects were divided into two groups: the HIIT (n= 26) and control group (n= 24). The HIIT group subjects underwent 12 weeks (3 sessions per week) of HIIT program, while the control group subjects kept to their normal daily activities. Fasting blood glucose levels, serum omentin-1 levels, lipid profile, and insulin resistance were evaluated at baseline and after the experiment. RESULTS: HIIT resulted in significant improvements in the subjects’ body composition, serum omentin-1 levels, lipid profiles, fasting insulin, HOMA-IR (p< 0.05). Further, highly significant negative correlations were observed between serum omentin levels, on the one hand, and body mass index, body weight, and waist circumference, on the other. CONCLUSIONS: Twelve weeks of HIIT may be an effective training strategy to improve serum omentin-1 levels, body composition, lipid profile, and insulin sensitivity in diabetic obese men.

Body composition and functional correlates of CF youth experiencing pulmonary exacerbation and recovery

BACKGROUND

Youth with cystic fibrosis (CF) and pulmonary exacerbation (PEx) often experience weight loss, then rapid weight gain. Little is known about body composition and its relationship to functional outcomes during this critical period.

METHODS

Twenty CF youth experiencing PEx were assessed on the day following admission and 7-17 days later at discharge for body mass index (BMI), fat mass index (FMI), lean mass index (LMI), skeletal muscle mass index (SMMI), and functional measures: percent predicted forced expiratory volume in 1 second (FEV1) (ppFEV1), maximal inspiratory and expiratory pressures (MIPs and MEPs), and handgrip strength (HGS). Changes from admission to discharge and correlations among body composition indices and functional measures at both times are reported.

RESULTS

Upon admission, participant BMI percentile and ppFEV1 varied from 2 to 97 and 29 to 113, respectively. Thirteen had an LMI below the 25th percentile and nine had a percent body fat above the 75th percentile. BMI and FMI increased significantly (p = 0.03, 0.003) during hospitalization. LMI and SMMI did not change. FEV1 and MIPS increased (p = 0.0003, 0.007), independent of weight gain, during treatment. HGS did not improve.

CONCLUSIONS

Many youth with CF, independent of BMI, frequently carried a small muscle mass and disproportionate fat at the time of PEx. During hospital treatment, weight gain largely represented fat deposition; muscle mass and strength did not improve. A need for trials of interventions designed to augment muscle mass and function, and limit fat mass accretion, at the time of PEx is suggested by these observations.

The Effects of Metabolism Tracker Device (Lumen) Usage on Metabolic Control in Adults with Prediabetes: Pilot Clinical Trial

INTRODUCTION

Prediabetes is a risk factor for type 2 diabetes mellitus (T2DM). However, it may be reversed via lifestyle changes. Lumen is a novel handheld device that measures exhaled CO2 producing results in agreement with those of indirect calorimetry when assessing metabolic fuel usage. The aim of this study was to examine the effects of following Lumen's personalized, measurement-guided lifestyle intervention program on anthropometric and metabolic variables in adults with prediabetes.

METHODS

A 12-week single-arm intervention study was conducted in 27 participants. Body composition and blood markers were measured at the start and end of the study. Each participant took a daily morning (fasted) measurement and received feedback on their metabolic state (i.e., their degree of fat vs. carbohydrate oxidation). Participants were then provided with personalized daily guidelines for their carbohydrate, fat, and protein consumption, along with recommended lifestyle changes.

RESULTS

Intention-to-treat analysis revealed a significant decrease in body weight (5.99 kg, p < 0.001), comprising a significant reduction in percentage body fat (2.93%, p < 0.001) and waist circumference (6.23 cm, p < 0.001). Significant reductions were also observed in glycated hemoglobin A1c (0.27%, p < 0.001), triglycerides (0.45 mg/dL, p < 0.001), and systolic blood pressure (0.5 mm Hg, p < 0.05).

CONCLUSION

In a 12-week pilot study of participants with prediabetes, Lumen usage significantly improved multiple metabolic parameters, demonstrating its potential to deliver better clinical outcomes for patients with T2DM and metabolic syndrome.

Resistance training volume does not influence lean mass preservation during energy restriction in trained males

This study investigated the effects of a relatively high- versus moderate-volume resistance training program on changes in lean mass during caloric restriction. Thirty-eight resistance-trained males were randomized to perform either a high-volume (HVG; 5 sets/exercise) or a moderate-volume (MVG; 3 sets/exercise) resistance training program. Both groups were supervised during lower body training. Participants consumed 30 kcal/kg for 6 weeks after 1 week of weight maintenance (45 kcal/kg), with protein intake fixed at 2.8 g/kg fat-free mass. Muscle thickness of the m. rectus femoris, body composition, contractile properties, stiffness, mood, and sleep status were assessed at pre-, mid-, and post-study. No significant group × time interaction was observed for muscle thickness of the m. rectus femoris at 50% (∆ [post-pre] 0.36 ± 0.93 mm vs. ∆ -0.01 ± 1.59 mm; p = 0.226) and 75% length (∆ -0.32 ± 1.12 mm vs. ∆ 0.08 ± 1.14 mm; p = 0.151), contractility, sleep, and mood in the HVG and MVG, respectively. Body mass (HVG: ∆ -1.69 ± 1.12 kg vs. MVG: ∆ -1.76 ± 1.76 kg) and lean mass (∆ -0.51 ± 2.30 kg vs. ∆ -0.92 ± 1.59 kg) decreased significantly in both groups (p = 0.022), with no between-group difference detected (p = 0.966). High-volume resistance training appears to have neither an advantage nor disadvantage over moderate-volume resistance training in terms of maintaining lean mass or muscle thickness. Given that both groups increased volume load and maintained muscle contractility, sleep quality, and mood, either moderate or higher training volumes conceivably can be employed by resistance-trained individuals to preserve muscle during periods of moderate caloric restriction.

Changes in body composition during the macrocycle of professional football players in relation to sports nutrition knowledge

Professional football players are obligated to meet the physical demands and maintain the best possible performance throughout the whole macrocycle. It is important to assess the players' nutrition knowledge, identify areas that require increased nutrition awareness and identify the impact of knowledge on changes in body composition as this can affect the players' health and performance. This study aimed to assess changes in the body composition of professional football players during the macrocycle of the spring round of the football championship and to identify the correlation between nutrition knowledge and maintaining body composition. The study included 38 football players. The players' body compositions were analyzed 6 times during the macrocycle consisting of preparatory, competitive, and transition periods using the Direct Segmental Multi-Frequency Bioelectrical Impedance Analysis method. Athletes completed the Nutrition for Sport Knowledge Questionnaire to assess their nutrition knowledge. During the preparatory period, a statistically significant negative correlation was demonstrated between the players' knowledge about the subsections of micronutrients in the diet and the dispersion of the adipose percentage tissue content (r = -0.36, p = 0.03). In the competitive period, there was a statistically significant negative correlation between the players' knowledge of sports nutrition and the dispersion of lean body mass (r = -0.46, p = 0.004), and skeletal muscle mass (r = -0.36, p = 0.03). During the transition period, a statistically significant negative correlation between the players' knowledge of weight control and the dispersion of body mass (r = -0.47, p = 0.00) and BMI values (r = -0.48, p = 0.00) was identified. The player's knowledge about the subsection of macronutrients significantly negatively correlated with the dispersion of skeletal muscle mass content (r = -0.33, p = 0.05). Nutrition knowledge has an impact on the stability of body composition during all analyzed periods: preparatory, competitive, and transition periods.

Assessment of Standing Multi-Frequency Bioimpedance Analyzer to Measure Body Composition of the Whole Body and Limbs in Elite Male Wrestlers

We investigated differences in body composition measurements for the whole body and limb segments in elite male wrestlers between results of multi-frequency bioelectrical impedance analyses (MF_BIA) and dual energy X-ray absorptiometry (DXA). Sixty-six elite male wrestlers from Taiwan were recruited. Wrestlers' body fat percentage (PBF_WB), whole body fat-free mass (FFM_WB), whole body lean soft tissue mass (LSTM_WB), and fat-free mass of arms, legs and trunk (FM_Arms, FFM_Legs, FFM_Trunk) were measured by MF_BIA and DXA, and analyzed using Pearson correlation coefficient and Bland-Altman plot. Correlations of FFM_WB, LSTM_WB, and PBF_WB between devices were 0.958, 0.954, and 0.962, respectively. Limits of agreement (LOA) of Bland-Altman plot were -4.523 to 4.683 kg, -4.332 to 4.635 kg and -3.960 to 3.802%, respectively. Correlations of body composition parameters FFM_Arms, FFM_Legs and FFM_Turnk between devices in each limb segment were 0.237, 0.809, and 0.929, respectively; LOAs were -2.877 to 2.504 kg, -7.173 to -0.015 kg and -5.710 to 0.777 kg, respectively. Correlation and consistency between the devices are high for FFM, LSTM and PBF but relatively low for limb segment FFM. MF_BIA may be an alternative device to DXA for measuring male wrestlers' total body composition but limb segment results should be used cautiously.

Exercise-Based Cancer Rehabilitation Program Improves Phase Angle in Breast Cancer Survivors

Phase angle (PhA) is an index of cell membrane integrity and prognostic indicator of survival and quality of life in cancer survivors. The efficacy of exercise-based cancer rehabilitation programs (ExCR) on PhA is unknown. To assess the effect of ExCR on PhA in breast cancer survivors. Fifty-nine female breast cancer survivors (61 ± 9 years) were referred to the ExCR by their oncologist and participated in one-on-one exercise-based training for 90 minutes, 3 times a week, for 12 weeks. Training sessions included 45 minutes of resistance training at intensities between 40-85% of 1-repetition maximum with a rate of perceived exertion (RPE) between 3-8, 30 minutes of cardiorespiratory training at intensities between 40-85% of heart rate reserve with an RPE between 3-8, and 15 minutes of flexibility training. Participants completed pre- and post-measurements of body composition, cardiorespiratory endurance, flexibility, muscular endurance, muscular strength, and PhA (Inbody 770). PhA significantly increased (p < 0.05) after ExCR (PhA_pre = 4.56; PhA_post = 4.64; Δ = 1.8%). Changes in measures of muscular strength have a weak but significant positive relationship (r = 0.20-0.39; p < 0.05) with changes in PhA. There was no relationship between changes in PhA and changes in cardiorespiratory endurance or muscular endurance. A 12-week ExCR significantly improves PhA in breast cancer survivors. Training muscular strength may be an integral component of ExCR with the objective of improving PhA.

Bioimpedance and Dual-Energy X-ray Absorptiometry Are Not Equivalent Technologies: Comparing Fat Mass and Fat-Free Mass

Bioimpedance (BIA) is the most frequently used technology for body composition assessment at a daily clinical level, mostly due to its low price and user-friendly operation. However, many doubts persist regarding its physiological meaning and applicability. The present study aimed to compare one BIA system and the Dual-Energy X-ray Absorptiometry (DXA) for the characterization of body composition in a previously selected cohort of healthy adult participants. A descriptive observational cross-sectional study included a final sample of 121 participants, 93 women and 28 men, with a mean age of 28.26 ± 9.72 years old and a mean body mass index (BMI) of 22.68 ± 3.13 kg/m². Statistics involved paired t-tests and agreement analysis by the Bland-Altman method. BIA underestimated the percent body fat (%BF) by 5.56% and overestimated Fat-Free Mass (FFM) by 2.90 kg. A strong positive correlation between both technologies was found for FFM (r = 0.980) and the %BF (r = 0.932), but the disagreement was statistically significant (p < 0.001). Although DXA and BIA seem to correlate, these technologies are not congruent. Therefore, the risk of (mis)interpretation and bias is clear with BIA, potentially impacting the nutritional planning of clinical dietitians and the further results of its patients.

Validation of a multi-frequency bioelectrical impedance analysis device for the assessment of body composition in older adults with type 2 diabetes

Background

Aging and type 2 diabetes (T2DM) are associated with an increased risk of sarcopenia. Diagnosis of sarcopenia is commonly done using dual-energy X-ray absorptiometry (DXA) in specialized settings. Another available method for assessing body composition is direct segmental multi-frequency bioelectrical impedance analysis (DSMF-BIA). Here, we examine the accuracy of a DSMF-BIA (InBody-770) for assessing body composition in older adults with T2DM when compared to DXA.

Methods

Eighty-four obese/overweight older adults (49 women, 71 ± 5 years) with T2DM who were recruited for the CEV-65 study and had both DSMF-BIA and DXA assessments at baseline were included. The analysis included Bland–Altman plots and intra class correlation coefficients. Sub-analyses were performed according to gender and following 10 weeks of interventions (diet, circuit training, and Empagliflozin).

Results

The leg lean mass results according to DSMF-BIA and DXA were 14.76 ± 3.62 kg and 15.19 ± 3.52 kg, respectively, with no difference between devices according to Bland–Altman analyses (p = 0.353). Assessment of appendicular skeletal mass index did not differ between DSMF-BIA and DXA (7.43 vs. 7.47 kg/m²; p = 0.84; ICC = 0.965, p < 0.0001; mean difference −0.068, p = 0.595). Gender and treatment interventions did not modify the accuracy of the DSMF-BIA when compared to DXA.

Conclusions

In older adults with T2DM the degree of agreement between DSMF-BIA and DXA, was high, supporting the use of DSMF-BIA to measure muscle mass.

Prognostic significance of sarcopenia as determined by bioelectrical impedance analysis in patients with advanced pancreatic cancer receiving gemcitabine plus nab‑paclitaxel: A retrospective study

Sarcopenia often affects patients with various types of cancer, and has been reported to affect patient prognosis and therapeutic effects. However, to the best of our knowledge, there are no reports on the relationship between gemcitabine plus nab-paclitaxel combination therapy (GnP) and sarcopenia in patients with unresectable pancreatic cancer. The present study analyzed the relationship between overall survival (OS), progression-free survival (PFS), response rate, disease control rate, adverse events (AEs) and sarcopenia in patients with pancreatic cancer treated with GnP. A total of 121 consecutive patients with advanced pancreatic cancer who received GnP as first-line chemotherapy between January 2015 and December 2017 were retrospectively analyzed. GnP consisted of 1,000 mg/m² gemcitabine and 125 mg/m² nab-paclitaxel, which were administered on days 1, 8 and 15 every 4 weeks. The skeletal muscle index (SMI) was calculated using bioimpedance analysis (BIA) as an index of sarcopenia prior to GnP. The patients were divided into sarcopenia (n=41) and non-sarcopenia (n=80) groups using cutoff values of 8.87 and 6.42 kg/m² for male and female patients, respectively. The sarcopenia and non-sarcopenia groups had a median OS of 8.1 and 13.9 months, respectively [hazard ratio (HR) 0.79; 95% confidence interval (CI) 0.53-1.20], and a median PFS of 4.3 and 6.3 months, respectively (HR 0.63; 95% CI 0.42-0.95). The response and disease controls rate were not statistically different between the groups (20 vs. 32%, P=0.20; 81 vs. 80%, P=1.0). In addition, comparison of common grade 3 and 4 AEs between the two groups revealed no statistically significant differences. In conclusion, the results of the present study indicated that SMI obtained by BIA may be a predictor of treatment response and prognosis in patients with advanced pancreatic cancer who undergo GnP.

Acute Water Supplementation Improved the Body Composition of Young Female Adults After Water Restriction of 12 h in Baoding, China: A Randomized Controlled Trial (RCT)

Insufficient intake of water may influence the balance of water in the human body. In this study, we explore the impacts of water supplementation on body composition indices among young adults after 12 h of water restriction, with the aim to determine the optimum volume of water for improving body water composition. A randomized controlled trial study was conducted among 64 young men and women in Baoding, China. After fasting overnight for 12 h, anthropometric measurements and urine and blood samples were collected as a baseline test at 8:00 a.m. of Day 2. Body composition was determined by measuring the ECW (extracellular water), ICW (intracellular water), and TBW (total body water) through bioelectrical impedance analysis (BIA). The participants were randomly divided into four groups, including water supplementation (WS) groups 1, 2, and 3, with 500, 200, and 100 mL of water, respectively, and a no water supplementation (NW) group. After 90 min, they were reassessed in a rehydration test (at 10:00 a.m. of Day 2). Repeated measurement ANOVA was used to assess the impact of water supplementation on body composition. Comparing the baseline and rehydration tests, interactions between time and volume were not significant among the men (all p > 0.05). Among women, a significant interaction was only found in ECW (p = 0.043), with TBW tending toward being significant (p = 0.055). Comparing the baseline and rehydration tests, the ECW in WS group 1, WS group 3, and the NW group all decreased (p = 0.028, p = 0.001, and p = 0.029), with reductions of 0.1, 0.3, and 0.2 kg, respectively; however, no significant decrease was observed in WS group 2 (p = 0.329). Furthermore, comparing the WS groups with the NW group in the rehydration test, the differences were not significant (p = 1.000, p = 1.000, and p = 0.288, respectively). Between men and women within groups, all of the body composition indices differed significantly, both at baseline and rehydration tests (all p < 0.05). Water supplementation led to changes in the distribution of the water content in young female adults in this study-but not men-after 12 h of water restriction, with no decrease in ECW. Finally, we found that 200 mL was the minimum volume capable of improving the water content distribution in participants in this study.

Trial Registration

[www.chictr.org.cn], identifier [ChiCTR-IOR-17011568].

Feasibility of a Digital Therapeutic Program for Cancer Patients During Active Treatment: Analysis of Engagement, Retention and Quality of Life (Preprint)

Background

Increasing evidence shows that lifestyle interventions can improve the symptoms, quality of life (QoL), and even overall survival of patients with cancer. Digital therapeutics (DTx) can help implement behavioral modifications and empower patients through education, lifestyle support, and remote symptom monitoring.

Objective

We aimed to test the feasibility of a DTx program for patients with cancer, as measured by engagement, retention, and acceptability. In addition, we explored the effects of the program on cancer-related QoL.

Methods

We conducted a 4-week single-arm trial in Iceland, where DTx was delivered through a smartphone app. The intervention consisted of patient education about mindfulness, sleep, stress, and nutrition; lifestyle coaching; and the completion of daily missions for tracking physical activity and exercise, reporting patient-reported outcomes (PROs), practicing mindfulness, and logging healthy food intake. Information on program engagement and retention, step goal attainment, as well as PROs were collected throughout the study. QoL was measured using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30 at baseline and follow-up.

Results

In total, 30 patients with cancer undergoing active therapy were enrolled, and 29 registered in the app (23 female, 18 with breast cancer; mean age 52.6, SD 11.5 years). Overall, 97% (28/29) of participants were active in 3 of the 4 weeks and completed the pre- and postprogram questionnaires. The weekly active days (median) were 6.8 (IQR 5.8-6.8), and 72% (21/29) of participants were active at least 5 days a week. Users interacted with the app on average 7.7 (SD 1.9) times per day. On week 1, all 29 participants used the step counter and logged an average of 20,306 steps; 21 (72%) participants reached their step goals of at least 3000 steps per day. On week 4, of the 28 active users, 27 (96%) were still logging their steps, with 19 (68%) reaching their step goals. Of the 28 participants who completed the satisfaction questionnaire, 25 (89%) were likely to recommend the program, 23 (82%) said the program helped them deal with the disease, and 24 (86%) said it helped them remember their medication. QoL assessment showed that the average global health status, functioning, and symptom burden remained stable from baseline to follow-up. In all, 50% (14/28) of participants reported less pain, and the average pain score decreased from 31 (SD 20.1) to 22.6 (SD 23.2; P=.16). There was no significant change in PROs on the quality of sleep, energy, and stress levels from the first to the last week.

Conclusions

The high retention, engagement, and acceptability found in this study demonstrate that multidisciplinary DTx is feasible for patients with cancer. A longer, full-scale randomized controlled trial is currently being planned to evaluate the efficacy of the intervention.

A Comparison of Double Poling Physiology and Kinematics Between Long-Distance and All-Round Cross-Country Skiers

Purpose

The objective of this study was to compare physiological and kinematic responses to double poling (DP) between long-distance (LDS) and all-round (ARS) cross-country skiers.

Methods

A number of five world-class LDS (28.8 ± 5.1 years, maximal oxygen uptake (VO_2max): 70.4 ± 2.9 ml·kg⁻¹·min⁻¹) and seven ARS (22.3 ± 2.8 years, VO_2max: 69.1 ± 4.2 ml·kg⁻¹·min⁻¹) athletes having similar training volumes and VO_2max performed three identical tests; (1) submaximal and incremental tests to exhaustion while treadmill DP to determine gross efficiency (GE), peak oxygen uptake (DP-VO_2peak), and peak speed; (2) submaximal and incremental running tests to exhaustion to determine GE, VO_2max (RUN-VO_2max), and peak speed; and (3) an upper-body pull-down exercise to determine one repetition maximum (1RM) and peak power. Physiological responses were determined during both DP and running, together with the assessments of kinematic responses and electromyography (EMG) of selected muscles during DP.

Results

Compared to ARS, LDS reached higher peak speed (22.1 ± 1.0 vs. 20.7 ± 0.9 km·h⁻¹, p = 0.030), DP-VO_2peak (68.3 ± 2.1 vs. 65.1 ± 2.7 ml·kg⁻¹·min⁻¹, p = 0.050), and DP-VO_2peak/RUN-VO_2max ratio (97 vs. 94%, p = 0.075) during incremental DP to exhaustion, as well as higher GE (17.2 vs. 15.9%, p = 0.029) during submaximal DP. There were no significant differences in cycle length or cycle rate between the groups during submaximal DP, although LDS displayed longer relative poling times (~2.4% points) at most speeds compared to ARS (p = 0.015). However, group × speed interaction effects (p < 0.05) were found for pole angle and vertical fluctuation of body center of mass, with LDS maintaining a more upright body position and more vertical pole angles at touchdown and lift-off at faster speeds. ARS displayed slightly higher normalized EMG amplitude than LDS in the muscles rectus abdominis (p = 0.074) and biceps femoris (p = 0.027). LDS performed slightly better on 1RM upper-body strength (122 vs. 114 kg, p = 0.198), with no group differences in power in the pull-down exercise.

Conclusions

The combination of better DP-specific aerobic energy delivery capacity, efficiency, and technical solutions seems to contribute to the superior DP performance found among specialized LDS in comparison with ARS.

Modal Frequencies Associations with Musculoskeletal Components of Human Legs for Extracorporeal Bone Healing Assessment Based on a Vibration Analysis Approach

Reliable and quantitative assessments of bone quality and fracture healing prompt well-optimised patient healthcare management and earlier surgical intervention prior to complications of nonunion and malunion. This study presents a clinical investigation on modal frequencies associations with musculoskeletal components of human legs by using a prototype device based on a vibration analysis method. The findings indicated that the first out-of-plane and coupled modes in the frequency range from 60 to 110 Hz are associated with the femur length, suggesting these modes are suitable quantitative measures for bone evaluation. Furthermore, higher-order modes are shown to be associated with the muscle and fat mass of the leg. In addition, mathematical models are formulated via a stepwise regression approach to determine the modal frequencies using the measured leg components as variables. The optimal models of the first modes consist of only femur length as the independent variable and explain approximately 43% of the variation of the modal frequencies. The subsequent findings provide insights for further development on utilising vibration-based methods for practical bone and fracture healing monitoring.

Analysis of Total and Segmental Body Composition Relative to Fitness Performance Measures in Law Enforcement Recruits

Law enforcement agencies often test the fitness performance and body composition of incoming recruits. This study investigated the relationships between whole and segmental body composition, and fitness tests in law enforcement recruits. A retrospective analysis of 72 male and 11 female recruits was performed. Bioelectrical impedance analysis (BIA) variables were: lean mass (LM), upper-extremity lean mass (UELM), trunk LM, lower-extremity lean mass (LELM), fat mass (FM), upper-extremity fat mass (UEFM), trunk FM, and lower-extremity fat mass (LEFM). Fitness tests included: vertical jump (VJ), peak anaerobic power (PAPw), 75-yard pursuit run (75PR), push-ups, sit-ups, 2-kg medicine ball throw (MBT), and the multi-stage fitness test (MSFT). Partial correlations and ANCOVAs between quartiles assessed relationships between body composition and performance. Significant moderate-to-large relationships were found; LM, UELM, trunk LM, LELM all related to PAPw (r = 0.500-0.558) and MBT (r = 0.494-0.526). FM, UEFM, trunk FM, LEFM all related to VJ (r = -0.481 to -0.493), 75PR (r = 0.533-0.557), push-ups (r = -0.484 to -0.503), sit-ups (r = -0.435 to -0.449), and MSFT (r = -0.371 to -0.423). The highest LM quartile (4) had superior PAPw and MBT than LM quartiles 1-3. Higher FM quartiles performed poorer in VJ, push-ups, and sit-ups. The 75PR quartiles 2, 3, and 4 were slower than quartile 1, and MSFT quartile 4 completed less shuttles. Total and segmental measures of LM and FM shared the same relationships; lower FM and higher LM related to better performance. Monitoring body composition could help guide training to optimize performance.

Water Distribution Changes in Complex Decongestive Treatment for Leg Lymphedema: Quantitative Evaluation by Direct Segmental Multi-Frequency Bioimpedance Analysis

Background: There is a need for a simple method for the quantitative evaluation of lymphedema swelling. In this study, we performed a direct segmental multi-frequency impedance analysis in patients with leg lymphedema.

Methods: The subjects were 36 patients (6 men and 30 women) with 46 lymphedema legs. The average age was 61 years. All patients had International Society of Lymphology stage II lymphedema. Swelling ratio and ultrasound subcutaneous tissue echo-free space (FS) were examined. InBody 770 was used to measure the extracellular water (ECW), intracellular water (ICW), and total body water (TBW) volumes. Changes before and after complex decongestive treatment (CDT) were examined.

Results: In 26 unilateral cases, the ECW, ICW, and TBW volumes of the affected legs were higher than those of the contralateral unaffected legs, and the ECW/TBW ratio was significantly higher in the affected legs (0.41) than in the contralateral unaffected legs (0.391). There was a significant correlation between the leg swelling ratio and the ECW/TBW ratio between the affected and contralateral unaffected legs (correlation coefficient=0.882). Ultrasound findings of the 46 affected legs were classified into no FS (group 0), minimal or only horizontal FS (group 1), and cobblestone-like FS (group 2). The ECW/TBW ratio of the affected legs in each group was 0.393 (14 legs), 0.407 (10 legs), and 0.426 (22 legs) respectively, demonstrating significant differences among the 3 groups. After CDT, the amount of water decreased in the affected legs and increased in the trunks and both upper limbs. The ECW/TBW ratio decreased significantly, from 0.432 to 0.414 in the affected legs, from 0.401 to 0.392 in the unaffected legs, and from 0.413 to 0.402 in the trunks. The ECW/TBW ratio had not changed and remained below 0.4 in the upper limbs.

Conclusion: The segmental water contents measured by direct segmental multi-frequency impedance analysis correlates well with the degree of lymphedema swelling, and subcutaneous echo findings and can demonstrate water distribution change before and after CDT, which is considered to be a useful quantitative evaluation method for lymphedema. (This is secondary publication from Jpn J Phlebol 2020; 31(1): 1–7.)

High-Protein Energy-Restriction: Effects on Body Composition, Contractile Properties, Mood, and Sleep in Active Young College Students

Background: It is often advised to ensure a high-protein intake during energy-restricted diets. However, it is unclear whether a high-protein intake is able to maintain muscle mass and contractility in the absence of resistance training. Materials and Methods: After 1 week of body mass maintenance (45 kcal/kg), 28 male college students not performing resistance training were randomized to either the energy-restricted (ER, 30 kcal/kg, n = 14) or the eucaloric control group (CG, 45 kcal/kg, n = 14) for 6 weeks. Both groups had their protein intake matched at 2.8 g/kg fat-free-mass and continued their habitual training throughout the study. Body composition was assessed weekly using multifrequency bioelectrical impedance analysis. Contractile properties of the m. rectus femoris were examined with Tensiomyography and MyotonPRO at weeks 1, 3, and 5 along with sleep (PSQI) and mood (POMS). Results: The ER group revealed greater reductions in body mass (Δ -3.22 kg vs. Δ 1.90 kg, p < 0.001, partial η ² = 0.360), lean body mass (Δ -1.49 kg vs. Δ 0.68 kg, p < 0.001, partial η ² = 0.152), body cell mass (Δ -0.85 kg vs. Δ 0.59 kg, p < 0.001, partial η ² = 0.181), intracellular water (Δ -0.58 l vs. Δ 0.55 l, p < 0.001, partial η ² = 0.445) and body fat percentage (Δ -1.74% vs. Δ 1.22%, p < 0.001, partial η ² = 433) compared to the CG. Contractile properties, sleep onset, sleep duration as well as depression, fatigue and hostility did not change (p > 0.05). The PSQI score (Δ -1.43 vs. Δ -0.64, p = 0.006, partial η ² = 0.176) and vigor (Δ -2.79 vs. Δ -4.71, p = 0.040, partial η ² = 0.116) decreased significantly in the ER group and the CG, respectively. Discussion: The present data show that a high-protein intake alone was not able to prevent lean mass loss associated with a 6-week moderate energy restriction in college students. Notably, it is unknown whether protein intake at 2.8 g/kg fat-free-mass prevented larger decreases in lean body mass. Muscle contractility was not negatively altered by this form of energy restriction. Sleep quality improved in both groups. Whether these advantages are due to the high-protein intake cannot be clarified and warrants further study. Although vigor was negatively affected in both groups, other mood parameters did not change.

Association of Body Composition with Type 2 Diabetes: A Retrospective Chart Review Study

This study analyzed the body composition of individuals with type 2 diabetes (T2DM). In this retrospective chart review study, body composition was measured through multifrequency bioelectrical impedance analysis (InBody 770). Body composition assessments were conducted in individuals with T2DM, who were aged ≥18 years. The parameters included body mass index (BMI), body fat mass (BFM), fat-free mass (FFM), visceral fat area, percent body fat (PBF), appendicular skeletal muscle mass (ASM), and skeletal muscle index (SMI). One-way ANOVA and independent t-tests were used to calculate differences in body composition distribution by age and sex. A total of 2404 participants were recruited. The prevalence of overall low muscle mass and sarcopenic obesity was 28.0% and 18.7%, respectively, which increased with age. The overall prevalence of obesity when PBF was used was 71.5%, which was higher than that when BMI was applied (32.4%). The normal BMI group exhibited a prevalence of low muscle mass of 55.6% and sarcopenic obesity of 34.8%. For both men and women, bodyweight, BFM, FFM, ASM, and SMI all decreased with age. The prevalence of low muscle mass and sarcopenic obesity was high in older adults and people with normal BMI. Using BMI to assess obesity and determine insufficient muscle mass underestimates the prevalence of obesity and neglects the problems of sarcopenia and high body fat in people with normal BMI.

Low Grip Strength and Muscle Mass Increase the Prevalence of Osteopenia and Osteoporosis in Elderly Women

The risk of developing low muscle strength and muscle mass is affected by aging, osteopenia, and osteoporosis and increases with age. The purpose of this study was to investigate the prevalence and cutoff values for osteoporosis and osteopenia according to the level of grip strength and muscle mass associated with sarcopenia. A cross-sectional study was conducted, and data from 734 women aged from 60 to 79 years old who visited the healthcare center from 2016 to 2019 were analyzed. Bone mineral density was measured on the lumbar spine from 1-4 using dual X-ray absorptiometry. Osteopenia and osteoporosis were classified on the basis of a T-score ranging from -1.0 to -2.4 and under -2.5, respectively. The diagnostic criteria for sarcopenia were a grip strength of <18 kg and muscle mass of <5.7 kg/m² according to the Asian Working Group of Sarcopenia. Logistic regression analysis was used to determine the odds ratio, and the receiver operating characteristic curve was applied for the cutoff values. There were 351 (47.8%) patients with osteopenia and 152 (20.7%) patients with osteoporosis. The prevalence of osteopenia increased 1.593 times in the lowest grip strength group and 1.810 times in the lowest muscle mass group (p < 0.05). For osteoporosis, the lowest grip strength increased 2.512 times and the lowest muscle mass increased 2.875 times, compared to the highest grip strength group. In the sarcopenia group, osteopenia increased 2.451 times and osteoporosis increased 3.137 times, compared to the non-sarcopenia group (p < 0.05). In conclusion, the prevalence of osteoporosis and osteopenia was increased in elderly women with low grip strength and muscle mass.

Effects of 4 Weeks of a Technique-Specific Protocol with High-Intensity Intervals on General and Specific Physical Fitness in Taekwondo Athletes: An Inter-Individual Analysis

The aim of this research was to compare the effects of a technique-specific high-intensity interval training (HIIT) protocol vs. traditional taekwondo training on physical fitness and body composition in taekwondo athletes, as well as to analyse the inter-individual response. Utilising a parallel controlled design, sixteen male and female athletes (five females and 11 males) were randomly divided into an experimental group (EG) that participated in the technique-specific HIIT and a control group (CG) that participated in traditional taekwondo training. Both groups trained three days/week for four weeks. Squat jump (SJ), countermovement jump (CMJ), 5-metre sprint (5M), 20-metre shuttle run (20MSR), taekwondo specific agility test (TSAT), multiple frequency speed of kick test (FSKT_MULT), total kicks, and kick decrement index (KDI), as well as body composition were evaluated. Results indicate that there are no significant differences (p > 0.05) in the factors group and time factor and group by time interaction (p > 0.05). Although percentage and effect size increases were documented for post-intervention fitness components in TSAT, total kicks, KDI, and 20MSR, responders and non-responders were also documented. In conclusion, a HIIT protocol based on taekwondo-specific technical movements does not report significant differences in fitness and body composition compared to traditional taekwondo training, nor inter-individual differences between athletes.

Relative fat mass is a better tool to diagnose high adiposity when compared to body mass index in young male adults: A cross-section study

BACKGROUND AND AIM

Relative fat mass (RFM) is a new method to estimate whole-body fat percentage in adults using an anthropometric linear equation. We aimed to assess the association between RFM and body fat (BF), evaluated by dual x-ray absorptiometry (DXA) or bioelectrical impedance (BIA), in young male adults.

METHODS

Eighty-one young males were assessed for BF fat and free fat mass (by BIA and DXA), waist circumference. BMI and RFM were then calculated from data collected from the subjects. The agreement between BMI and RFM or BIA/DXA was assessed by Pearson's Correlation and Kappa index. Univariate and multivariate linear regression were applied.

RESULTS

Analyzing all the participants together, the correlation between RFM and DXA (r_DXA = 0.90) or RFM and BIA (r_BIA = 0.88) were slightly higher than the correlation between BMI and DXA (r_DXA = 0.79) or BMI and BIA (r_BIA: 0.82). When analyzed by BF, low BF (LBF) individuals showed a much higher correlation with RFM (r_DXA = 0.58; r_BIA = 0.73) than BMI (r_DXA = 0.24; r_BIA: 0.46). However, subjects with excess BF (EBF) presented similar correlations when comparing RFM (r_DXA = 0.80; r_BIA = 0.64) and BMI (r_DXA = 0.78; r_BIA = 0.64). In general, RFM presented a higher strength of agreement with DXA and BIA (k_DXA = 0.75; k_BIA = 0.67) than BMI (k_DXA = 0.63; k_BIA = 0.60). Multivariable linear regression also revealed high associations between RFM and DXA or RFM and BIA (r²_DXA = 0.85; r²_BIA = 0.81).

CONCLUSION

Our findings suggest that RFM shows a good correlation and association with BF measured by DXA and BIA in young male adults. Furthermore, RFM seems to be better correlated to BF in LBF individuals when compared to BMI. Therefore, further studies investigating RFM as a tool to assess BF and obesity are motivated.

Associations of Sex Hormones and Hormonal Status With Arterial Stiffness in a Female Sample From Reproductive Years to Menopause

OBJECTIVE

Loss of sex hormones has been suggested to underlie menopause-associated increment in cardiovascular risk. We investigated associations of sex hormones with arterial stiffness in 19-58-years-old women. We also studied associations of specific hormonal stages, including natural menstrual cycle, cycle with combined oral contraceptives (COC) and menopausal status with or without hormone therapy (HT), with arterial stiffness.

METHODS

This study includes repeated measurements of 65 healthy women representing reproductive (n=16 natural, n=10 COC-users) and menopause (n=5 perimenopausal, n=26 postmenopausal, n=8 HT-users) stages. Arterial stiffness outcomes were aortic pulse wave velocity (PWVao) and augmentation index (AIx%) assessed using Arteriograph-device. Generalized estimating equation models were constructed to investigate associations of each hormone (wide age-range models) or hormonal stage (age-group focused models) with arterial stiffness. PWVao models with cross-sectional approach, were adjusted for age, relative fitness, fat mass and mean arterial pressure, while models with longitudinal approach were adjusted for mean arterial pressure. AIx% models used the same approach for adjustments and were also adjusted for heart rate.

RESULTS

Negative and positive associations with arterial stiffness variables were observed for estradiol and follicle-stimulating hormone, respectively, until adjustment for confounding effect of age. In naturally menstruating women, AIx% was higher at ovulation (B=3.63, p<0.001) compared to the early follicular phase. In COC-users, PWVao was lower during active (B=-0.33 - -0.57, p<0.05) than inactive pills. In menopausal women, HT-users had higher PWVao (B=1.43, p=0.03) than postmenopausal non-HT-users.

CONCLUSIONS

When using wide age-range assessments covering reproductive to menopausal lifespan it is difficult to differentiate age- and hormone-mediated associations, because age-mediated influence on arterial stiffness seemed to overrule potential hormone-mediated influences. However, hormonal status associated differentially with arterial stiffness in age-group focused analyses. Thus, the role of sex hormones cannot be excluded. Further research is warranted to resolve potential hormone-mediated mechanisms affecting arterial elasticity.

Usefulness of Psoas Muscle Cross-Sectional Area in Evaluating Physical Performance in Patients with Liver Cirrhosis

Objectives To investigate the relationship between the psoas muscle cross-sectional area and physical performance in patients with liver cirrhosis. Methods This study analyzed ambulatory patients with liver cirrhosis aged &lt; 65 years, who underwent abdominal computed tomography (CT) and Short Physical Performance Battery (SPPB) tests from December 2018 to December 2019. A total of 46 patients (36 men, 10 women) were included. In abdominal CT scans, the psoas muscle cross-sectional area (mm²) was measured at the distal end-plate level of the L4 vertebral body and normalized by dividing by height (m). Physical performance was evaluated using SPPB. A correlation analysis between the psoas muscle cross-sectional area and SPPB was performed. Kruskal-Wallis test was used to determine differences in the psoas muscle cross-sectional area and SPPB according to the Child-Pugh classification. Multiple regression analysis was performed to determine factors affecting SPPB. Results The correlation coefficient between the psoas muscle cross-sectional area and SPPB was 0.459 at the P &lt; 0.01 level. No difference was observed in the psoas muscle cross-sectional area and SPPB according to the Child-Pugh classification. The psoas muscle cross-sectional area was a factor affecting SPPB in multiple regression analysis. Conclusions Abdominal CT is an essential diagnostic tool in patients with liver cirrhosis. Ambulatory patients with liver cirrhosis aged &lt; 65 years could have reduced physical performance. In this study, the psoas muscle cross-sectional area was correlated with physical performance and was a factor affecting physical performance. The psoas muscle cross-sectional area and physical performance should be evaluated in patients with liver cirrhosis.

Effects of 12 weeks of water aerobics on body composition in those affected by breast cancer

Exercise may prevent changes in body composition and provide an effective means of improving the side effects of treatment without causing lymphedema.

PURPOSE

Test the effectiveness of a 12-week water aerobics program on body composition and lymphedema risk in breast cancer survivors.

METHODS

Body composition analysis was completed at weeks 0, 6, and 12 weeks.

RESULTS

Ten females completed all testing. Baseline subject characteristics were as follows: age (59.40 ± 8.22 years), weight (169.91 ± 41.70 lbs), body fat percent (%BF) (40.15 ± 9.84%), body fat mass (BFM) (71.27 ± 31.50 lbs), lean body mass (LBM) (98.66 ± 13.24 lbs), skeletal muscle mass (SMM) (53.17 ± 8.09 lbs), intracellular water (ICW) (44.24 ± 6.18 lbs), and extracellular water (ECW) (28.91 ± 3.62 lbs). One-way ANOVA showed no statistically significant differences over time as determined for weight (F(2.27) = 0.002, P = 0.96), %BF (F(2.27) = 0.004, P = 0.97), BFM (F(2.27) = 0.001, P = 0.97), LBM (F(2.27) = 0.013, P = 0.95), SMM (F(2.27) = 0.027, P = 0.91), ICW (F(2.27) = 0.021, P = 0.93), and ECW (F(2.27) = 0.01, P = 0.94) across the 12 weeks.

CONCLUSIONS

A water aerobics program for 12 weeks was not enough to observe changes in body composition nor did it increase the risk for lymphedema and may be a safe exercise method for breast cancer survivors.