Whole-body dual-energy X-ray absorptiometry demonstrates better reliability than segmental body composition analysis in college-aged students

Impact of skeletal muscle mass of the trunk and extremities on standing spine parameters before and after surgery for adult spinal deformity with a minimum 2-year follow-up

PURPOSE

The effect of skeletal muscle mass of the trunk and extremities on sagittal imbalance of the spine before and after surgery for adult spinal deformity (ASD) has not been elucidated. The purpose of this study was to examine the correlation between reduced skeletal muscle mass of the trunk and extremities, as well as spinopelvic parameters, preoperatively, postoperatively and at least 2 years after surgery for ASD.

METHODS

This retrospective observational study included 140 consecutive patients who had undergone surgery for ASD and were followed-up for at least 2 years and whose skeletal muscle mass could be measured preoperatively using whole-body dual-energy X-ray absorptiometry. Correlations between skeletal muscle mass and spinopelvic parameters were assessed preoperatively, postoperatively, and after 2 years of follow-up.

RESULTS

All spinopelvic parameters were significantly improved postoperatively compared with preoperatively. Between the postoperative period and two years post-surgery, a significant loss of correction was observed in SVA and GT. Trunk muscles mass showed significant negative correlations with preoperative PT, SS, PI-LL, SVA, GT, and TPA, but there was no significant correlation with postoperative parameters. Through univariate and multivariate regression analysis, lower limb skeletal muscle mass showed a significant negative correlation with SVA at two years postoperatively and the loss of corrected SVA (ΔSVA) over two years.

CONCLUSION

This study revealed that lower extremity muscle mass was implicated in the loss of corrected SVA 2 years after surgery. This study is clinically meaningful as it suggests that strength training for the lower extremities, performed preoperatively and/or postoperatively, can improve sagittal imbalances of the spine in patients with severe ASD or maintain SVA after corrective surgery.

LEVEL OF EVIDENCE: 3

Dietary antioxidant capacity is inversely associated with F2- isoprostane and body fat percentage in elite soccer referees

Background Dietary antioxidant Capacity (DaC) has been used as a tool for predicting plasma and dietary antioxidant concentrations. However, the DaC association with oxidative stress (OS) and body composition parameters is an unexplored area, mainly in physically active individuals. Given the potential for increased OS in physically active individuals, it becomes crucial to investigate this association. The aim of this study was to analyze the association between DaC, OS biomarkers, and body composition in healthy and physically active individuals. Methods This Cross-sectional study included 20 male soccer referees. Body composition measurements (body mass, fat mass, lean mass, and waist circumference), OS biomarkers (F2-isoprostane, total antioxidant state, total oxidative status, reduced glutathione, oxidized glutathione, superoxide dismutase, glutathione peroxidase (GPx) and catalase), and DaC were evaluated. Linear regression models were used to determine the association between DaC and the dependent variables. The study was approved by the Human Research Ethics Committee of the Federal University of Santa Catarina (UFSC), CAAE 82584318.0.0000.0121, and file no. 2.572.301. Results DaC was inversely associated with F2-isoprostane (p = 0.044), GPx activity (p = 0.048), and body fat percentage (p = 0.025). Conclusions Increased DaC in physically active individuals may bring benefits related to biomarkers of OS, such as decreasing F2-isoprostane and increasing GPx activity. The increase in DaC also showed an improvement in body composition, demonstrated by the lower percentage of body fat in the study subjects.

Relationship of female pelvic floor muscle function and body composition: cross-sectional study

PURPOSE

Investigate the relationship between female pelvic floor muscle (PFM) function and body composition.

METHODS

Cross-sectional study-participants answered sociodemographic and urogynecological questions. The amount of fat mass was measured by dual-emission X-ray densitometry (DXA), and subcutaneous fat thickness was assessed by abdominal ultrasound. PFM assessment was performed using the Modified Oxford Scale and vaginal manometry. Descriptive analysis, independent t test, spearman correlation, and univariate regression were performed.

RESULTS

Ninety-nine women were included. All body composition variables evaluated, except subcutaneous fat thickness, indicated that women with a higher concentration of fat in the pelvic, android, and visceral region have lower maximum voluntary PFM contraction strength assessed by Modified Oxford Scale and manometry. The univariate model pointed out that the fat concentration increases the chances of reduced PFM strength in the entire body (0.6%), android (5.4%), visceral region (25.3%), and pelvic (89.9%). There was a correlation between the concentration of total, pelvic, and android fat with MVC/average peak.

CONCLUSION

The accumulation of "total", "pelvic", "android", and "visceral" fat mass is correlated with reduction in PFM strength, and there is an association between MVC and the variables of total and segmented fat. However, pelvic fat concentration is predictive in 89.9% of cases.

What About Water? Implications for Body Composition Assessment in Military Personnel

ABSTRACT

Sergi, TE, Roberts, BM, and Heileson, JL. What About Water? Implications for Body Composition Assessment in Military Personnel. J Strength Cond Res 38(9): e534-e540, 2024-Body composition standards ensure service members maintain physical fitness, wellness, and support mission readiness. Anthropometric techniques (i.e., height/mass, circumference-based "tape test") have been the primary screening and percent body fat (%BF) assessment method in military personnel for about 4 decades. Recently, the Army and Marine Corps have implemented more advanced body composition assessment methods, such as air displacement plethysmography (ADP), multifrequency bioelectrical impedance analysis (MF-BIA), and dual-energy x-ray absorptiometry (DXA), to serve as supplemental %BF assessment after failing the tape test. Although supplemental assessments are intended to improve on the accuracy and precision of the tape test, preassessment standardization, specifically regarding acute water ingestion (AWI), is lacking. Thus, the purpose of this narrative review was to (a) summarize the available literature regarding the influence of AWI on body composition estimates derived from ADP, MF-BIA, and DXA and (b) provide evidence-based recommendations for researchers and practitioners. Studies indicate that AWI increases %BF estimates with ADP (4 of 6 [4/6] observations) and MF-BIA (6/7), whereas AWI increases muscle mass (6/6) and likely decreases %BF (2/3) when obtained by DXA. In conclusion, ADP, MF-BIA, and DXA are susceptible to confounding from AWI, leading to inaccurate body composition estimates that may negatively affect the careers of military personnel. Based on the findings from this narrative review, military practitioners and researchers should (a) follow manufacturer guidelines for calorie intake [food and fluid] and exercise avoidance, (b) conduct urine-specific gravity testing [if possible], and (c) limit AWI to <250 ml before assessment.

Korean Nationwide Exploration of Sarcopenia Prevalence and Risk Factors in Late Middle-Aged Women

This study examined specific clinical risk factors for age-related loss of skeletal muscle mass in late middle-aged women with sarcopenia. This Korean nationwide cross-sectional study analyzed data from 2814 community-dwelling women aged from 50 to 64 years old and screened them for sarcopenia. This study examined various risk factors such as age; height; weight; body mass index; waist circumference; skeletal muscle mass index; systolic and diastolic blood pressure; smoking and drinking habits; fasting glucose levels; triglyceride; and cholesterol levels. Complex sampling analysis was used for the data set. Prevalence of sarcopenia with a weighted prevalence of 13.43% (95% confidence interval: 2.15-15.78). The risk factors for sarcopenia were height, body mass index, waist circumference, skeletal muscle mass index, systolic blood pressure, diastolic blood pressure, triglyceride level, and total cholesterol level (p < 0.05). Weight, fasting glucose level, drinking status, and smoking status were not significant (p > 0.05). These results are expected to contribute to the existing literature on sarcopenia and identify potential risk factors associated with the development of sarcopenia in late middle-aged females. By acknowledging prevalence and recognized risk factors, healthcare professionals may augment their proficiency in recognizing and discerning potential instances of sarcopenia in female patients.

The effect of regular running on body weight and fat tissue of individuals aged 18 to 65

BACKGROUND

Age and reduction in performed physical activity cause physiological changes that include an increase in body fat (BF) and visceral fat (VF) during aging. These parameters, together with increased body mass (BM), are some of the risk factors of several noninfectious diseases. However, changes in body composition can be influenced by regular physical activity. Running is a suitable, accessible, and the most effective physical activity cultivating people. The objective of this study is to investigate the effects of long-term, regular PA, specifically recreational running, on changes in body composition among recreational adult runners covering a weekly distance of at least 10 km, compared with inactive adult individuals within the same age bracket.

METHODS

The study included 1296 runners and inactive individuals (691 male and 605 female), divided into 5 age groups: 18-25, 26-35, 36-45, 46-55, and 56-65 years. Runners are as follows: ran ≥ 10 km/week, and inactive is as follows: did not follow the WHO 2020 physical activity recommendations. The measured parameters included BM, BF, and VF. To check statistical significance, the Mann-Whitney U-test was used. Practical significance was assessed using the effect of size.

RESULTS

All age groups of runners were selected to include individuals who run at least 10 km per week. In fact, they ran, on average, from 21.6 to 31.4 km per week in relation to age and showed significantly lower values of BM, BMI, BF, and VF (p < 0.05) than inactive individuals. Exceptions included insignificant differences (p > 0.05) in BM and BMI in males in the age category of 18-25 and in females in the age category of 18-25 and 26-35.

CONCLUSION

The selected runners had to run at least 10 km per week. Their actual average volume was significantly higher (from 21.6 to 31.4 km/week), and the results showed that it could lead to significantly better body composition values. It may lead to significant changes in body mass, body fat, and visceral fat. It may meet the contemporary societal expectations for physical activities that are both achievable and effective at the lowest possible volume.

Why Temporal Inference Stimulation May Fail in the Human Brain: A Pilot Research Study

Temporal interference stimulation (TIS) aims at targeting deep brain areas during transcranial electrical alternating current stimulation (tACS) by generating interference fields at depth. Although its modulatory effects have been demonstrated in animal and human models and stimulation studies, direct experimental evidence is lacking for its utility in humans (in vivo). Herein, we directly test and compare three different structures: firstly, we perform peripheral nerve and muscle stimulation quantifying muscle twitches as readout, secondly, we stimulate peri-orbitally with phosphene perception as a surrogate marker, and thirdly, we attempt to modulate the mean power of alpha oscillations in the occipital area as measured with electroencephalography (EEG). We found strong evidence for stimulation efficacy on the modulated frequency in the PNS, but we found no evidence for its utility in the CNS. Possible reasons for failing to activate CNS targets could be comparatively higher activation thresholds here or inhibitory stimulation components to the carrier frequency interfering with the effects of the modulated signal.

Accuracy in body composition scanning by adult half-body DXA scanning

INTRODUCTION

dual-energy X-ray absorptiometry (DXA) is the gold standard method, although one limitation is the size of the scan area.

OBJECTIVE

the objective was to verify the accuracy of body composition (BC) scanning through half-body DXA scanning compared to standard total body scanning.

METHODS

a study was conducted on 145 volunteers. Weight and height were assessed. Body mass index (BMI) was calculated. DXA was used for whole-body scan (WBS) and half-body scan (HBS). WBS was used as the reference method and the following indicators were extracted: bone mineral content (BMC), fat mass (FM), lean soft tissue (LST) and percentage fat mass (%FM).

RESULTS

no differences were observed in the body composition indicators (BMC, FM, LST and %FM) when compared between the reference WBS scanner and the HBS scanner. The predictive power between both scans ranged in both sexes between R2 = 0.94 and 0.98. The DRI desirable reproducibility index values defining the degree of agreement between both scans ranged from 0.97 to 0.99, and the values for precision (0.97 to 0.99) and accuracy (0.99) were high.

CONCLUSION

HBS scanning by DXA evidenced agreement, and high values of accuracy and precision to assess body composition indicators (BMC, FM, LST and %FM).

Dietary protein and the glycemic index handle insulin resistance within a nutritional program for avoiding weight regain after energy-restricted induced weight loss

BACKGROUND AND AIM

The role of dietary protein and glycemic index on insulin resistance (based on TyG index) within a nutritional program for weight loss and weight maintenance was examined.

METHODS

This study analyzed 744 adults with overweight/obesity within the DIOGenes project. Patients who lost at least 8% of their initial weight (0-8 weeks) after a low-calorie diet (LCD) were randomly assigned to one of five ad libitum diets designed for weight maintenance (8-34 weeks): high/low protein (HP/LP) and high/low glycemic index (HGI/LGI), plus a control. The complete nutritional program (0-34 weeks) included both LCD plus the randomized diets intervention. The TyG index was tested as marker of body mass composition and insulin resistance.

RESULTS

In comparison with the LP/HGI diet, the HP/LGI diet induced a greater BMI loss (p < 0.05). ∆TyG was positively associated with resistance to BMI loss (β = 0.343, p = 0.042) during the weight maintenance stage. In patients who followed the HP/LGI diet, TyG (after LCD) correlated with greater BMI loss in the 8-34 weeks period (r = -0.256; p < 0.05) and during the 0-34 weeks intervention (r = -0.222, p < 0.05) periods. ΔTyG1 value was associated with ΔBMI2 (β = 0.932; p = 0.045) concerning the HP/LGI diet.

CONCLUSIONS

A HP/LGI diet is beneficial not only for weight maintenance after a LCD, but is also related to IR amelioration as assessed by TyG index changes. Registration Clinical Trials NCT00390637.

Comparison of body segment models for female high jumpers utilising DXA images

In motion analysis of sport competitions, the question is often about the most convenient choice for defining the segment endpoints when no visible landmarks can be used. The purpose of the present study was to determine the location of the body centre of mass (CoM) of female high jumpers by using a high accuracy reaction board and two different segment models: Dempster (1955) and de Leva (1996). Digitising the bony landmarks from the images of dual energy x-ray absorptiometry (DXA) and overhead digital camera were used to compare the digitising accuracy. The location of the CoM determined by a reaction board was 55.88 ± 0.52% of subjects' body height. The segment model of Dempster digitized from DXA images (56.66 ± 0.50%) differed from the reference values of reaction board (p = 0.004), whereas the model of de Leva (56.06 ± 0.61%) showed no significant difference. The model of de Leva adjusted for female subjects differed only slightly (0.32%), thus, providing appropriate model for female high jumpers. Since the digitised bony landmarks in the DXA images are obviously very close to the correct locations, the differences in results between the segment models and reaction board is most likely due to inaccuracies in the model itself and/or generalisation of one model to different body structures. When the segment landmarks were estimated without any markers on the body, the results did not differ much from the DXA results.

Gender-Specific Risk Factors and Prevalence for Sarcopenia among Community-Dwelling Young-Old Adults

Sarcopenia in the elderly is a serious global public health problem. Numerous sarcopenia studies classified their subjects into a single group, but health conditions and body composition vary according to age. This study examined the prevalence of sarcopenia according to gender and assessed the gender-specific risk factors in young-old adults. In this study, 2697 participants in Korea aged from 65 to 74 years were analyzed from Korea National Health and Nutrition Examination Surveys. The prevalence of sarcopenia in males and females was 19.2% (CI 95%: 16.4–22.3) and 26.4% (23.7–29.4), respectively. The risk factors in men were age, body mass index (BMI), waist circumference (WC), skeletal muscle index (SMI), fasting glucose (FG), triglyceride, and systolic blood pressure (SBP). Their odd ratios were 1.447, 0.102, 1.494, 0.211, 0.877, 1.012, and 1.347. The risk factors in women were age, height, weight, BMI, WC, SMI, and fasting glucose with values of 1.489, 0.096, 0.079, 0.158, 0.042, and 1.071, respectively. The prevalence of sarcopenia was higher in females than in males. Overall, the clinical risk factors in males were age, height, BMI, WC, SMI, FG, triglyceride, and SBP. Age, height, weight, BMI, WC, SMI, and FG were the risk factors for women.

Moderate-Intensity Exercise Preserves Bone Mineral Density and Improves Femoral Trabecular Bone Microarchitecture in Middle-Aged Mice

Background

Aging leads to significant bone loss and elevated osteoporosis risk. Exercise slows age-related bone loss; however, the effects of various moderate-intensity exercise training volumes on bone metabolism remain unclear. This study aimed to determine the degree to which different volumes of moderate-intensity aerobic exercise training influence bone mineral density (BMD), bone mineral content (BMC), femoral trabecular bone microarchitecture, and cortical bone in middle-aged mice.

Methods

Twenty middle-aged male C57BL/6 mice were randomly assigned 8 weeks of either (1) non-exercise (CON); (2) moderate-intensity with high-volume exercise (EX_MHV); or (3) moderate-intensity with low-volume exercise (EX_MLV) (N=6–7, respectively). Femoral BMD and BMC were evaluated using dual energy X-ray absorptiometry, and trabecular and cortical bone were measured using micro-computed tomography.

Results

Femoral BMD in EX_MHV but not EX_MLV was significantly higher (P<0.05) than in CON. The distal femoral fractional trabecular bone volume/tissue volume (BV/TV, %) was significantly higher (P<0.05) in both EX_MHV and EX_MLV than in CON mice. Increased BV/TV was induced by significantly increased trabecular thickness (mm) and tended to be higher (P<0.10) in BV (mm³) and lower in trabecular separation (mm) in EX_MHV and EX_MLV than in CON. The femoral mid-diaphysis cortical bone was stronger in EX_MLV than EX_MHV.

Conclusions

Long-term moderate-intensity aerobic exercise with low to high volumes can be thought to have a positive effect on hindlimb BMD and attenuate age-associated trabecular bone loss in the femur. Moderate-intensity aerobic exercise may be an effective and applicable exercise regimen to prevent age-related loss of BMD and BV.

Cross-sectional and longitudinal associations between subcutaneous adipose tissue thickness and dual-energy X-ray absorptiometry fat mass

The present study examined cross-sectional and longitudinal relationships between total and segmental subcutaneous tissue thicknesses from ultrasonography (US) and total and segmental fat mass (FM) estimates from dual-energy X-ray absorptiometry (DXA). Traditional US FM estimates were also examined. Twenty resistance-trained males (mean ± SD; age: 22.0 ± 2.6 years; body mass: 74.8 ± 11.5 kg; DXA fat: 17.5 ± 4.5%) completed a 6-week supervised resistance training programme while consuming a hypercaloric diet. Pre- and post-intervention body composition was assessed by DXA and B-mode US. Data were analysed using Pearson's correlation (r), Lin's correlation coefficient (CCC), paired t-tests, Wilcoxon signed-rank tests and Bland-Altman analysis, as appropriate. Cross-sectionally, correlations were observed between total DXA FM and total subcutaneous tissue thickness (r = 0.88). Longitudinally, a correlation was observed between total DXA FM changes and total subcutaneous tissue changes (r = 0.49, CCC = 0.38). Correlations of similar magnitudes were observed for the upper body and trunk estimates, but DXA FM changes were unrelated to subcutaneous tissue changes for the lower body and arms. Cross-sectionally, US 2-compartment FM and DXA FM were correlated (r = 0.91, CCC = 0.83). Longitudinally, a weaker correlation was observed (r = 0.47, CCC = 0.33). In summary, longitudinal associations between US and DXA are weaker than cross-sectional relationships; additionally, correlations between US subcutaneous tissue and whole-body DXA FM appear to be driven by the trunk region rather than appendages. Reporting raw skinfold thicknesses rather than FM estimates alone may improve the utility of techniques based on subcutaneous tissue thickness, such as US and skinfolds.

Nutritional consequences of endoluminal gastroplasty in the treatment of morbidly obese patients

BACKGROUND

The Endoscopic sleeve gastroplasty (ESG) is one of the new advanced restrictive techniques of bariatric endoscopy. The principle of this bariatric technique is the reduction of stomach volume through endoscopic plication. The long-term efficacy and metabolic effects of this procedure are the subject of this study.

METHODS

20 patients were enrolled; four men, sixteen women. Then they were followed for 24 months in terms of glycemic control, body composition, vitamin, and nutritional status. Observed parameters included glucose, triacylglycerols, high- and low-density lipoprotein cholesterol, micro and macro nutrients, fat mass, and lean body mass.

RESULTS

We observed significant weight loss and a decrease body composition resulted from procedure vs. baseline, with levels of blood glucose also showing statistically significant reductions. The most notable decline in measured values was observed in period six months after the procedure. No significant changes were observed in measurement of micronutrients.

CONCLUSIONS

Good restriction results were obtained following ESG, which might be mediated via altered glucose metabolism. The ESG method has shown a positive effect on fat and muscle mass. Unlike surgical methods, there were no deficits or deficiencies, especially in terms of essential vitamin levels.

Concurrent validity of five prediction equations to evaluate fat percentage in a sports group expected to yield high performance from Medellín, Colombia

INTRODUCTION

No equations to predict the body composition of athletes from Medellín expected to have high performance have been constructed and, thus, decisions regarding their training and nutrition plans lack support.

OBJECTIVE

To calculate the concurrent validity of five prediction equations for fat percentage in a group of athletes from Medellín, Colombia, expected to yield high performance.

MATERIALS AND METHODS

We conducted a cross-sectional analysis to validate diagnostic tests using secondary-source data of athletes under the age of 18 who were part of the "Medellín Team". The gold standard was dual-energy X-ray densitometry (DEXA). We analyzed the Slaughter, Durnin and Rahaman, Lohman, and Johnston prediction equations, as well as the five-component model. We used the intraclass correlation coefficient to assess the consistency of the methods and the Bland-Altman plot to calculate the average bias and agreement limits of each of the equations.

RESULTS

We included 101 athletes (50,5 % of them women). The median age was 14,8 years (IR: 13,0 - 16,0). The concurrent validity was "good/excellent" for the Johnston and the Durnin and Rahaman equations and the five-components model. The Lohman equation overestimated the fat percentage in 12,7 points. All of the equations showed broad agreement limits.

CONCLUSIONS

The Durnin and Rahaman and the Johnston equations, as well as the fivecomponent model, can be used to predict the FP in the study population as they showed a "good/excellent" concurrent validity and a low average bias. The equations analyzed have low accuracy, which hinders their use to diagnose the individual fat percentage within this population.

Strength, Endocrine, and Body Composition Alterations across Four Blocks of Training in an Elite 400 m Sprinter

The ability to produce force rapidly has the potential to directly influence sprinting performance through changes in stride length and stride frequency. This ability is commonly referred to as the rate of force development (RFD). For this reason, many elite sprinters follow a combined program consisting of resistance training and sprint training. The purpose of this study was to investigate the strength, endocrine and body composition adaptations that occur during distinct phases of a block periodized training cycle in a 400 m Olympic level sprinter. The athlete is an elite level 400 m male sprinter (age 31 years, body mass: 74 kg, years of training: 15 and Personal Best (PB): 45.65 s). This athlete completed four distinct training phases of a block periodized training program (16 weeks) with five testing sessions consisting of testosterone:cortisol (T/C) profiles, body composition, vertical jump, and maximum strength testing. Large fluctuations in T/C were found following high volume training and the taper. Minor changes in body mass were observed with an abrupt decrease following the taper which coincided with a small increase in fat mass percentage. Jump height (5.7%), concentric impulse (9.4%), eccentric impulse (3.4%) and power ratio (18.7%) all increased substantially from T1 to T5. Relative strength increased 6.04% from T1 to T5. Lastly, our results demonstrate the effectiveness of a competitive taper in increasing physiological markers for performance as well as dynamic performance variables. Block periodization training was effective in raising the physical capabilities of an Olympic level 400 m runner which have been shown to directly transfer to sprinting performance.

Glycemic and cardiometabolic effects of exercise in South Asian Sri Lankans with type 2 diabetes mellitus: A randomized controlled trial Sri Lanka diabetes aerobic and resistance training study (SL-DARTS)

BACKGROUND AND AIMS

To examine the effects of aerobic training (AT) and resistance training (RT) compared to standard care on glycemic control in South Asian Sri Lankan adults with Type 2 Diabetes Mellitus (T2DM).

METHODS

Randomized controlled trial (RCT) with parallel-group design recruited 86 sedentary Sri Lankans (aged 35-65 years) with T2DM into aerobic training (AT, n = 28), resistance training (RT, n = 28) and control (CN, n = 30) groups. Supervised progressive exercise training consisting of 75 min per session, 2 days per week for 12 weeks was conducted. The primary outcome was pre- and post-intervention absolute change in hemoglobin A1c (HBA1c). Secondary outcomes were serum lipids, liver enzymes, chronic inflammatory status, anthropometry, body composition and blood pressure.

RESULTS

The absolute change in HbA1c of RT vs. CN was -0.08% (95% CI, 0.8% to -0.7%, p = 0.8) and AT vs. CN was -0.22% (95% CI, 0.95% to -0.5%). Subgroup analysis (n = 49) with a high baseline HbA1c (>7.5%), absolute reduction in HbA1c in exercise groups were statistically significant (RT vs. CN was -0.37%; 95% CI 1.3% to -0.6%, p = 0.04 and AT vs. CN was -0.57%; 95% CI 1.7% to -0.6%, p = 0.03). The effect sizes (total and subgroup HbA1c >7.5%) ranged from 0.7 to 1.0 in AT, 0.4 to 1.1 in RT compared to 0.35 to 0.6 for the CN. Secondary outcomes did not significantly differ among groups.

CONCLUSIONS

Exercise training 2 days/week improved glycemic control in Sri Lankan adults with T2DM and the effects were significant in high baseline HbA1c (>7.5%) groups (RT > AT).

Intensity of resistance training via self-reported history is critical in properly characterizing musculoskeletal health

BACKGROUND

Intensity of resistance training history might be omitted or poorly ascertained in prescreening or data questionnaires involving musculoskeletal health. Failure to identify history of high-versus low-intensity training may overlook higher effect sizes with higher intensities and therefore diminish the precision of statistical analysis with resistance training as a covariate and bias the confirmation of baseline homogeneity for experimental group designation. The purpose was to determine the degree to which a single question assessing participant history of resistance training intensity predicted differences in musculoskeletal health.

METHODS

In the first research aim, participants were separated into groups with a history (RT) and no history (NRT) of resistance training. The second research aim evaluated the history of resistance training intensity on muscular strength, lean mass, and bone mineral density (BMD), RT participants were reassigned into a low- (LIRT) or high-intensity resistance training group (HIRT). 83 males and 87 females (19.3 ± 0.6 yrs., 171.1 ± 9.9 cm, 67.1 ± 10.5 kg, 22.9 ± 2.8 BMI, 26.2 ± 7.2% body fat) completed handgrip dynamometry (HG) and dual-energy x-ray absorptiometry scans (DXA) for BMD and bone mineral-free lean mass (BFLM).

RESULTS

A 3-group method (NRT, LIRT, HIRT) reduced type-I error compared with the 2-group method (NRT, RT) in characterizing the likely effects of one's history of resistance training. For the second aim, HIRT had significantly (p < 0.05) greater HG strength (76.2 ± 2.2 kg) and arm BFLM (6.10 ± 0.16 kg) than NRT (67.5 ± 1.3 kg; 4.96 ± 0.09 kg) and LIRT (69.7 ± 2.0 kg; 5.42 ± 0.14 kg) while also showing significantly lower muscle quality (HG/BFLM) than NRT (13.9 ± 0.2 vs. 12.9 ± 0.3). HIRT had greater BMD at all sites compared to NRT (whole body = 1.068 ± 0.008 vs. 1.120 ± 0.014; AP spine = 1.013 ± 0.011 vs. 1.059 ± 0.019; lateral spine = 0.785 ± 0.009 vs. 0.846 ± 0.016; femoral neck = 0.915 ± 0.013 vs. 0.970 ± 0.022; total hip = 1.016 ± 0.012 vs. 1.068 ± 0.021 g/cm2) while LIRT revealed no significant skeletal differences to NRT.

CONCLUSIONS

Retrospective identification of high-intensity history of resistance training appears critical in characterizing musculoskeletal health and can be ascertained easily in as little as a single, standalone question. Both retrospective-questionnaire style investigations and pre-screening for potential participation in prospective research studies should include participant history of resistance training intensity.

Indicators of Sarcopenia: Sex Differences in Competitive Runners Prior to Peak Muscle Mass

Strength, muscle mass, and muscle quality have been observed to be compromised in low body-mass index individuals such as competitive runners, increasing their risk for sarcopenia. The purpose was to compare indices of sarcopenia in young runners to age, height, body-mass, and body-mass index-matched non-runners. Handgrip strength and arm composition from dual-energy x-ray absorptiometry (baseline-T1, T2=5.3±1.4, T3=11.5±0.7 months later) were assessed in 40 non-runners and 40 runners (19.3±0.7 vs. 19.2±1.1 years, 170.7±10.3 vs. 171.1±9.1 cm, 60.2±7.4 vs. 60.2±7.9 kg, 20.6±0.9 vs. 20.5±1.5 kg m^-2). The unitless variable of muscle quality, was defined as the sum of right and left maximal handgrip (in kg) divided by the sum of bone-free lean mass of both arms (in kg). Female runners displayed the highest muscle quality (T1=15.3±1.7; T3=15.7±2.0) compared to male runners (T1=13.7±1.4, p < 0.001; T3=14.2±1.6, p < 0.001) and male non-runners (T1=12.4±1.8, p=0.001; T3=13.2±1.6, p < 0.001), while female non-runners (T1=14.6±2.5, p=0.154; T3=15.1 ±2.2, p=0.124) showed higher muscle quality than male non-runners. Higher muscle quality in low-body-mass index females persists over one-year during young-adulthood and while running contributes to whole-body muscle mass accrual, it does not appear to be significantly associated with improvements in the most commonly used upper-body diagnostic indicator of sarcopenia.