Body composition changes by DXA, BIA and skinfolds during exercise training in women

A comparative analysis of body composition assessment by BIA and DXA in children with type II and III spinal muscular atrophy

BACKGROUND

Body composition analysis is a valuable tool for assessing and monitoring the nutritional status of children with spinal muscular atrophy (SMA). This study was designed to compare the consistency of bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA), as the gold standard method for assessing body composition in clinical practice when treating children with type II and III SMA.

METHODS

From 2019 to 2021, we performed a retrospective analysis of body composition by DXA and BIA measurement methods in patients with type II and III SMA treated at a Chinese tertiary children's hospital. Fat mass (FM), muscle mass (MM), bone mineral content (BMC), and visceral fat area (VFA) were compared using paired sample t-tests. We calculated Lin's concordance correlation coefficient (CCC) and Spearman correlation coefficient to verify the correlation between DXA and BIA measurements. Bland-Altman analysis was used to assess the consistency of the two methods.

RESULTS

Fifty-seven children with type II and III SMA were recruited. Compared with body composition measured by DXA, the average FM measured by BIA is significantly lower (P <0.001), whereas the average MM, BMC, and VFA measured by BIA are significantly higher (P < 0.001) in children with SMA. Overall, the difference between MM (Delta [BIA-DAX] = 1.6 kg) and FM (Delta [BIA-DAX] = -1.6 kg) measured by DXA and BIA was minor, whereas the difference of VFA (Delta [BIA-DAX] = -43.5 cm) was significantly large. Correlation analysis indicated a substantial correlation of MM (CCC = 0.96 [95% confidence interval (CI) = 0.93-0.98], r = 0.967 [P < 0.0001]) and FM (CCC = 0.95 [95% CI = 0.92-0.97], r = 0.953 [P < 0.0001]), and poor correlation of BMC (CCC = 0.61 [95% CI = 0.42-0.75], r = 0.612 [P < 0.0001]) and VFA (CCC = 0.54 [95% CI = 0.33-0.70], r = 0.689 [P < 0.0001]) measurements between the two methods. The Bland-Altman analysis suggests that the majority of participants were within LOA. In addition, differences in MM and VFA measurements between BIA and DAX increased according to patients' increasing height, whereas differences in FM and BMC did not differ with height.

CONCLUSION

BIA overestimates MM and underestimates the FM, BMC, and VFA in children with SMA compared with DXA measurements. Overall, the non-invasive, easy-to-use, and repeatable BIA measurements were found to be in good agreement with DXA measurements, especially for FM and MM, which are essential parameters for the nutritional evaluation of children with SMA.

Body Composition, Energy Availability, Training, and Menstrual Status in Female Runners

PURPOSE

To determine body composition, energy availability, training load, and menstrual status in young elite endurance running athletes (ATH) over 1 year, and in a secondary analysis, to investigate how these factors differ between nonrunning controls (CON), and amenorrheic (AME) and eumenorrheic (EUM) ATH. Correlations to injury, illness, and performance were also examined.

METHODS

Altogether 13 ATH and 8 CON completed the Low Energy Availability in Females Questionnaire. Anthropometric, energy intake, and peak oxygen uptake assessments were made at 4 time points throughout the year: at baseline post competition season, post general preparation, post specific preparation, and post competition season the following year. Logs of physical activity, menstrual cycle, illness, and injury were kept by all participants. Performance was defined using the highest International Association of Athletics Federations points prior to and after the study.

RESULTS

ATH had significantly lower body mass (P < .008), fat percentage (P < .001), and body mass index (P < .027) compared with CON, while energy availability did not differ between ATH and CON. The Low Energy Availability in Females Questionnaire score was higher in ATH than in CON (P < .028), and 8 ATH (vs zero CON) were AME. The AME had significantly more injury days (P < .041) and ran less (P < .046) than EUM, while total annual running distance was positively related to changes in performance in ATH (r < .62, P < .043, n < 11).

CONCLUSIONS

More than half of this group of runners was AME, and they were injured more and ran less than their EUM counterparts. Furthermore, only the EUM runners increased their performance over the course of the year.

Comparative analysis of BIA, IBC and DXA for determining body fat in American Football players

BACKGROUND

Body composition is frequently measured by sports, fitness, and healthcare professionals. Dual-Energy X-ray Absorptiometry (DXA) analysis is a validated measurement of body composition and is considered a criterion or "gold-standard" measurement. However, due to long scan times, accessibility and cost, conducting DXA scans on larger athletes (i.e., football players) is difficult. Hence fitness professionals, notably strength and conditioning coaches, typically use other methods to measure body composition. The aim of this study was to assess the accuracy of the Bioelectrical Impedance Analysis (BIA) and Integrative Body Composition (IBC) techniques to DXA body fat percent (BF%) in collegiate American Football players.

METHODS

Participants performed all three modes of body composition measurement: DXA, BIA (BIA-A [athlete]and BIA-NA [non-athlete modes]), and IBC, on the same day during early morning hours in a fasted state.

RESULTS

The BF% measured via all methods significantly correlated with BF% measured via DXA (i.e., BIA-A [P<0.001, r=0.903], BIA-NA [P<0.001, r=0.891], and IBC [P<0.001, r=0.867]). However, values obtained via BIA-A (athlete) (P<0.001) and IBC (P<0.001) methods under predicted BF%.

CONCLUSIONS

BIA and IBC can be used as an alternative to DXA for measuring BF% in American Football players. The BIA-A and IBC under predicted BF% compare to DXA, therefore, a correction formula can be utilized by coaches and athletes to predict BF% more accurately compared to IBC and BIA-A methods in American Football players.

Short-term resistance training in older adults improves muscle quality: A randomized control trial

The purpose of this study was to evaluate whether dumbbell resistance training (DBRT) and elastic band resistance training (EBRT) are equally beneficial in the older adult. Sixty-five healthy participants (mean±SD; age=66.5±7.09 years; height=165.2±10.6 cm; body mass=74.5±14.6 kg) volunteered for this study. Participants underwent a total body dual-energy x-ray absorptiometry (DXA) scan for segmental and total body muscle and fat estimation. Functional tests included the short physical performance battery, timed up-and-go, and heel-to-toe walk. Strength was measured on dominant handgrip strength, maximal bench press, and leg press. Participants were block randomized into one of three groups: elastic band resistance training (EBRT), dumbbell resistance training (DBRT), or control (CON). EBRT and DBRT were asked to visit the laboratory twice weekly over 6-weeks while CON maintained their daily routine. Data were analyzed using a two-way repeated measures ANOVA and an alpha set at 0.05. Results indicated there was a two-way interaction for bench press, leg press, upper- and lower-body muscle quality and total arm lean mass (p<0.05). Specifically, the EBRT and DBRT improved from pre to post for total arm lean mass (p<0.021, p<0.004, respectively). Additionally, for bench press and leg press, all groups improved pre to post training (p<0.05) with DBRT superior to CON. These data suggest that EBRT provides an effective, portable, and cost-effective means to enhance lower-body function and muscle quality in an aging population, yet DBRT may be more impactful for total-body improvements.

Influence of Specific Collagen Peptides and Concurrent Training on Cardiometabolic Parameters and Performance Indices in Women: A Randomized Controlled Trial

The purpose was to examine the effects of concurrent training (CT) combined with specific collagen peptides (SCP) intake on cardiometabolic parameters and performance indices in women. In a double-blind, placebo-controlled, randomized trial recreationally active women (n = 59) completed a 12-week CT training (3 day/week) and ingested 15 g of SCP (treatment group [TG]) or placebo (control group [CG]) on a daily basis. Running distance as a marker of endurance performance (time trial), velocity and heart rate at the lactate and anaerobic threshold (incremental running test) and body composition (bioelectrical impedance analysis [BIA]) were measured. BIA measurements included determination of fat mass (FM) and fat free mass (FFM). Additionally, muscular strength (one-repetition-maximum [1RM]) and muscular endurance (60% of 1RM) were assessed. After 12-weeks, TG had a higher increase in running distance (1,034 ± 643 m) compared to the CG (703 ± 356 m) indicated by a significant interaction effect (p < 0.05). Velocity at lactate and anaerobic threshold improved in both groups over time (p < 0.001), with no significant differences between groups. Similarly, heart rate at lactate threshold decreased over time (p < 0.001), with no time × group interaction. TG declined more in heart rate at anaerobic threshold (−8 ± 14 bpm) than the CG (−1 ± 7 bpm), which resulted in a significant interaction effect (p < 0.01). FM decreased over time in TG and CG (p < 0.001), with no group differences. On contrary, TG had a higher increase in FFM (0.8 ± 0.9 kg) compared to the CG (0.3 ± 1.0 kg) (time × group interaction: p < 0.05). Both, 1RM and muscular endurance improved over time (p < 0.001), with no significant group differences. In conclusion, supplementation of SCP in combination with CT resulted in a significant increase in endurance performance compared to the control group. This might potentially be a consequence of improved structural and cardiometabolic adaptations.

Effect of Progressive Resistance Training on Circulating Adipogenesis-, Myogenesis-, and Inflammation-Related microRNAs in Healthy Older Adults: An Exploratory Study

BACKGROUND

Functional and physiological adaptations induced by resistance training have been extensively studied in older adults. However, microRNA (miRNA) as the novel regulator in protective effects remains poorly understood.

OBJECTIVE

The purpose of an exploratory study was to analyze the response of a panel of circulating miRNAs to adaptations mediated by resistance training.

METHODS

Ten healthy older adults (age: 67.6 ± 2.2 years, 7 women and 3 men) without previous experience in resistance training were recruited. Blood samples were collected at baseline and after a 12-week resistance training. Next-generation sequencing was used to determine circulating miRNA responses to chronic resistance training.

RESULTS

After the 12-week training, physical functions including grip strength, lower body strength and endurance, and walking capacity were improved in the older adults, while the serum levels of leptin (from 18.1 ± 20.0 to 14.9 ± 17.6 ng/mL, p = 0.029) and tumor necrosis factor alpha (TNFα; from 4.4 ± 0.6 to 4.0 ± 0.6 pg/mL, p < 0.001) were significantly decreased. In addition, adipogenesis-related miRNAs (miR-103a-3p, -103b, -143-5p, -146b-3p, -146b-5p, -17-5p, -181a-2-3p, -181b-5p, -199a-5p, -204-3p, and -378c), anti-adipogenesis-related miRNAs (miR-155-3p, -448, and -363-3p), myogenesis-related miRNAs (miR-125b-1-3p, -128-3p, -133a-3p, 155-3p, -181a-2-3p, -181b-5p, -199a-5p, -223-3p, and -499a-5p), and inflammation-related miRNAs (miR-146b-3p, -146b-5p, -155-3p, -181a-2-3p, and -181b-5p) were changed significantly in the older adults after training (fold change >2, p < 0.05). The log2 fold change of miRNA-125-1-3p was inversely correlated with delta walking time (R = -0.685, p = 0.029) and change in insulin-like growth factor 1 (R = -0.644, p = 0.044).

CONCLUSIONS

Our results can help explain the link between specific circulating miRNAs and beneficial effects of resistance training on functional and physiological adaptations in older adults.

Comparison of Multifrequency Bioelectrical Impedance vs. Dual-Energy X-ray Absorptiometry for Assessing Body Composition Changes After Participation in a 10-Week Resistance Training Program

Schoenfeld, BJ, Nickerson, BS, Wilborn, CD, Urbina, SL, Hayward, SB, Krieger, J, Aragon, AA, and Tinsley, G. Comparison of multifrequency bioelectrical impedance vs. dual-energy x-ray absorptiometry for assessing body composition changes after participation in a 10-week resistance training program. J Strength Cond Res 34(3): 678-688, 2020-The purpose of this study was to assess the ability of multifrequency bioelectrical impedance analysis (MF-BIA) to determine alterations in total and segmental body composition across a 10-week resistance training (RT) program in comparison with the criterion reference dual-energy X-ray absorptiometry (DXA). Twenty-one young male volunteers (mean ± SD; age = 22.9 ± 3.0 years; height = 175.5 ± 5.9 cm; body mass = 82.9 ± 13.6 kg; body mass index = 26.9 ± 3.6) performed an RT program that included exercises for all major muscle groups. Body composition was assessed using both methods before and after the intervention; change scores were determined by subtracting pre-test values from post-test values for percent body fat ([INCREMENT]%BF), fat mass ([INCREMENT]FM), and fat-free mass ([INCREMENT]FFM). Mean changes were not significantly different when comparing MF-BIA with DXA for [INCREMENT]%BF (-1.05 vs. -1.28%), [INCREMENT]FM (-1.13 vs. -1.19 kg), and FFM (0.10 vs. 0.37 kg, respectively). Both methods showed strong agreement for [INCREMENT]%BF (r = 0.75; standard error of the estimate [SEE] = 1.15%), [INCREMENT]FM (r = 0.84; SEE 1.0 kg), and [INCREMENT]FFM (r = 0.71; SEE of 1.5 kg). The 2 methods were poor predictors of each other in regards to changes in segmental measurements. Our data indicate that MF-BIA is an acceptable alternative for tracking changes in FM and FFM during a combined diet and exercise program in young, athletic men, but segmental lean mass measurements must be interpreted with circumspection.

Concordance in prediction body fat percentage of Brazilian women in reproductive age between different methods of evaluation of skinfolds thickness

OBJECTIVE

To assess the utility of bioimpedance (BIA) and skinfolds thickness (SF) in body fat percentage measuring (%BF) compared to the reference method dual-energy x-ray absorptiometry (DXA) in Brazilian reproductive age women, as well as to estimate of inter- and intra-observer precision for SF.

SUBJECTS AND METHODS

170 women aged 18-37 years with BMI between 18 and 39.9 kg/m2 were selected for this cross-sectional study. Body density was evaluated through equations proposed by Jackson, Pollock and Ward (1980) (EqJPW) and Petroski (1995) (EqPET), and %BF was estimated by BIA, DXA and Siri's formula (1961). The SF were measured by two separate observers: A and B (to determine inter-observer variability), who measured the folds at three times with 10-minute interval between them (to determine intra-observer variability - we used only observer A).

RESULTS

The %BF by DXA was higher than those measured by SF and BIA (p<0.01, for all) of 90 volunteers. The Lin coefficient of agreement was considered satisfactory for %BF values obtained by EqJPW and BIA (0.55) and moderate (0.76) for sum of SF (ΣSF) values obtained by EqJPW and EqPET. No agreement was observed for the values obtained by SF (EqJPW and EqPET), BIA and DXA. Analysis of inter- and intra-observer of 59 volunteers showed that different measures of SF thickness met acceptability standards, as well as the % BF.

CONCLUSION

BIA and SF measurements may underestimate %BF compared with DXA. In addition, BIA and SF measurements are not interchangeable with DXA. However, our results suggest the equation proposed by Jackson, Pollock and Ward (three skinfolds) compared to BIA are interchangeable to quantify the %BF in Brazilian women in reproductive age. Furthermore, our results show acceptable accuracy for intra- and inter-observer skinfold measurements. Arch Endocrinol Metab. 2020;64(3):257-68.

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

The purpose of this investigation was to compare two different methods of assessing body composition (i.e., a multi-frequency bioelectrical impedance analysis (MF-BIA) and dual-energy x-ray absorptiometry (DXA)) over a four-week treatment period in exercise-trained men and women. Subjects were instructed to reduce their energy intake while maintaining the same exercise regimen for a period of four weeks. Pre and post assessments for body composition (i.e., fat-free mass, fat mass, percent body fat) were determined via the MF-BIA and DXA. On average, subjects reduced their energy intake by ~18 percent. The MF-BIA underestimated fat mass and percentage body fat and overestimated fat-free mass in comparison to the DXA. However, when assessing the change in fat mass, fat-free mass or percent body fat, there were no statistically significant differences between the MF-BIA vs. DXA. Overall, the change in percent body fat using the DXA vs. the MF-BIA was -1.3 ± 0.9 and -1.4 ± 1.8, respectively. Our data suggest that when tracking body composition over a period of four weeks, the MF-BIA may be a viable alternative to the DXA in exercise-trained men and women.

Trimodal prehabilitation for colorectal surgery attenuates post-surgical losses in lean body mass: A pooled analysis of randomized controlled trials

BACKGROUND & AIMS

Preservation of lean body mass is an important cancer care objective. The capacity for prehabilitation interventions to modulate the lean body mass (LBM) of colorectal cancer patients before and after surgery is unknown.

METHODS

A pooled analysis of two randomized controlled trials of trimodal prehabilitation vs. trimodal rehabilitation at a single university-affiliated tertiary center employing Enhanced Recovery After Surgery (ERAS) care was conducted. The prehabilitation interventions included exercise, nutrition, and anxiety-reduction elements that began approximately four weeks before surgery and continued for eight weeks after surgery. The rehabilitation interventions were identical to the prehabilitation interventions but were initiated only after surgery. Body composition, measured using multifrequency bioelectrical impedance analysis, was recorded at baseline, pre-surgery, 4 and 8 weeks after surgery. The primary outcome was change in LBM before and after colorectal surgery for cancer. A mixed effects regression model was used to estimate changes in body mass and body composition over time controlling for age, sex, baseline body mass index (BMI), baseline six-minute walk test (6MWT), and postoperative compliance to the interventions. NCT02586701 &NCT01356264.

RESULTS

Pooled data included 76 patients who followed prehabilitation and 63 patients who followed rehabilitation (n = 139). Neither group experienced changes in preoperative LBM. Compared to rehabilitated patients, prehabilitated patients had significantly more absolute and relative LBM at four and eight-weeks post-surgery in models controlling for age, sex, baseline BMI, baseline 6MWT, and compliance to the postoperative intervention.

CONCLUSION

Trimodal prehabilitation attenuated the post-surgical LBM loss compared to the loss observed in patients who received the rehabilitation intervention. Patients who receive neither intervention (i.e., standard of care) would be likely to lose more LBM. Offering a prehabilitation program to colorectal cancer patients awaiting resection is a useful strategy to mitigate the impact of the surgical stress response on lean tissue in an ERAS setting, and, in turn, might have a positive impact on the cancer care course.

CLINICAL TRIAL REGISTRATION

NCT02586701 &NCT01356264 (clinicaltrials.gov).

Effect of Hand Positioning on DXA Total and Regional Bone and Body Composition Parameters, Precision Error, and Least Significant Change

Dual-energy X-ray absorptiometry (DXA) body composition measurements are performed in both clinical and research settings for estimations of total and regional fat mass, lean tissue mass, and bone mineral content. Subject positioning influences precision and positioning instructions vary between manufacturers. The aim of the study was to determine the effect of hand position and scan mode on regional and total body bone and body composition parameters and determine protocol-specific body composition precision errors. Thirty-eight healthy subjects (men; mean age: 27.1 ± 12.1 yr) received 4 consecutive total body GE-Lunar iDXA (enCORE v 15.0) scans with re-positioning, and scan mode was dependent on body size. Twenty-three subjects received scans in standard mode and 15 received scans in thick scan modes. Two scans per subject were conducted with subject hands prone and 2 with hands mid-prone. The precision error (root mean squared standard deviation; percentage coefficient of variation) and least significant change for each protocol were determined using the International Society for Clinical Densitometry calculator. Hands placed in the mid-prone position increased arm bone mineral density (BMD) (standard mode: 0.185 g*cm^-2, thick mode: 0.265 g*cm^-2; p < 0.05), total body BMD (standard mode: 0.051 g*cm^-2, thick mode: 0.069 g*cm^-2; p < 0.001), and total body BMD Z-score (standard mode: 0.5. thick mode: 0.7; p < 0.001). This was due to reductions in bone area and bone mineral content. In standard mode, hands mid-prone reduced fat mass (0.05 kg, p < 0.05) and increased lean mass (0.11 kg, p < 0.05). There were no differences in body composition for thick mode scans. Hands mid-prone reduced lean mass precision error at the arms, trunk, and total body (p < 0.01). DXA clinical and research centers are advised to maintain consistency in their hand positioning and scan mode protocols, and consideration should be given to the hand positioning used for reference data. As a best practice recommendation, published DXA-based studies and reports for clinic-based total body assessments should ensure that subject positioning is fully described.

Limitations of body mass index to assess body composition due to sarcopenic obesity during leukemia therapy

Obesity as defined by body mass index percentile (BMI%) is strongly associated with relapse and poorer survival in childhood ALL. Whether BMI% accurately reflects body fat percentage (BF%) in this population is unknown. We conducted a prospective study assessing body composition during frontline ALL therapy. Dual-energy X-ray absorptiometry measured BF% and lean muscle mass (LMM) at diagnosis, end of Induction, and end of Delayed Intensification. Sarcopenic obesity (gain in BF% with loss of LMM) was surprisingly common during ALL treatment, resulting in poor correlation between changes in BMI% (expressed as Z-score) and BF% overall (r = -0.05) and within patients (r = -0.09). BMI Z-score and BF% changed in opposite directions in >50% of interval assessments. While BMI% at diagnosis is a suitable predictor of obesity/BF% for epidemiological studies, change in BMI% (as expressed as Z-score) does not reflect body composition. Studies evaluating obesity in leukemia should consider using direct measures of body composition.

Body Composition of Women's Ice Hockey Players: Comparison of Estimates Using Skinfolds and iDXA

Gilenstam, K and Geithner, CA. Body composition of women's ice hockey players: comparison of estimates using skinfolds and iDXA. J Strength Cond Res 33(9): 2496-2502, 2019-The purpose of this study was to compare percent fat (% fat) estimates from anthropometric equations using skinfolds (SKF) in women's ice hockey players with estimates obtained from Lunar iDXA. Data were collected on 19 elite female Swedish hockey players (mean age ± SD = 18.4 ± 2.4 years). Four SKF (triceps, abdominal, suprailiac, and thigh) were measured within 2 hours of iDXA assessments. The % fat estimates from iDXA and 4 anthropometric equations were compared using paired t tests, and a 1-way analysis of variance was used to compare % fat estimates from the anthropometric equations. Bland-Altman analyses were used to assess agreement between % fat estimates from SKF and iDXA. The significance level was set a priori at p ≤ 0.05. The % fat estimates from anthropometric equations were significantly lower than those from iDXA (mean ± SD: 26.85 ± 4.93%, p = 0.000). Bland-Altman analyses indicated mean differences of -7.96 to -10.13 percentage points between anthropometric equations and iDXA. Estimates of % fat from anthropometric equations (range: 16.72-18.89%) were within the range reported in earlier studies using the sum of 7 SKF. Thus, SKF offer a reasonable alternative to iDXA for this population but result in underestimates of % fat relative to iDXA. Strength and conditioning coaches should use the same body composition assessment method consistently, and interpret the results with caution, as they are estimates and not true values.

Body Composition Evaluation Issue among Young Elite Football Players: DXA Assessment

Accurate assessment of body composition is an important issue among athletes. Different methodologies generate controversial results, leading to a deep uncertainty on individual exercise prescriptions. Thus, this study aims to identify the differences between field methods, such as bioelectrical impedance (BIA) and skinfold assessment, with a clinical method, highly accurate, dual-energy X-ray absorptiometry (DXA), among elite young football players. Thirty-eight male football players with a mean (sd) age of 16.7 (0.87) years, involved in the Portuguese national competition of U16 (n = 13) and U19 (n = 25), were evaluated and objective measures of body composition, muscle strength and football skills were collected by trained specialists. Body composition was assessed using BIA (Tanita BC-418, Tanita Corp., Tokyo, Japan), in agreement with all the evaluation premises. Additionally, all athletes were evaluated using the clinical method DXA (Hologic Inc., Waltham, MA, USA). Among the U19 athletes, three skinfold sites (SKF) were assessed: chest, abdomin and thigh. The Spearman correlation coefficients and the mean difference between methods were calculated. The agreement between both methods was analyzed using Bland-Altman plots. Among the evaluated athletes, lower mean values of body fat % were found using BIA as a method of body composition assessment compared with DXA (12.05 vs. 15.58 for U16; 11.97 vs. 14.16 for U19). Despite the moderate correlation between methods (r = 0.33) to estimate the percentage of total fat, the median of the difference (DXA vs. BIA) was relevant in clinical terms, with 2.90% and 1.47% for U16 and U19 athletes, respectively. Stronger correlations were found between the sum of the SKF and DXA fat estimation (r = 0.68). The Bland-Altman plots showed a clear underestimation in the evaluations using the BIA, namely among athletes with better body composition profiles (8%–12% of fat). Using BIA, an underestimation of body fat assessment was observed among 94.5% of the athletes with less than 12% body fat mass. Among the evaluated athletes, fat mass was underestimated at a median value of 2.21% using BIA in comparison with DXA. The sum of the SKF showed a stronger correlation with the reference method (DXA) (r = 0.68) than BIA.

Health Benefits of Zumba Fitness Training: A Systematic Review

OBJECTIVE

As an alternative to the traditional approach to physical exercise, new kinds of organized physical activity have been developed designed to engage large segments of the population. Among these, Zumba fitness is extremely popular, with a growing number of participants. This article aims to summarize and analyze the body of evidence on the effects of Zumba fitness interventions on physical function, fitness, and wellbeing. TYPE: Systematic review.

LITERATURE SURVEY

Keyword "Zumba" was identified as term for the literature research in MEDLINE, Scopus, Bandolier, PEDro, and Web of Science. Only studies published in peer-reviewed journals written in English language were considered.

METHODOLOGY

Eleven manuscripts were classified as eligible with 586 total participants, ranging in age from 18 to 65 years. After a quality appraisal, we classified 4 studies as high-quality investigations and 7 as low quality. Results were summarized in several domains: "anthropometric parameters and body composition," "hormonal and metabolic profiles," "aerobic and cardiovascular performance," "muscular fitness parameters," and "quality of life, pain score and physical activity questionnaire."

SYNTHESIS

Results from this systematic review indicated that Zumba fitness could be considered an effective type of physical activity able to improve aerobic capacity. Small but positive benefits were noted for reducing body weight and other body measurements. Furthermore, other effects, including psychological and social benefits on quality of life, were found after Zumba fitness interventions. Otherwise, limited evidence described positive effects on muscular strength and flexibility.

CONCLUSIONS

Zumba fitness could be considered an effective type of physical activity able to improve aerobic capacity. Limited evidence described positive effects on muscular strength and flexibility.

LEVEL OF EVIDENCE

II.

Subcutaneous and segmental fat loss with and without supportive supplements in conjunction with a low-calorie high protein diet in healthy women

BACKGROUND

Weight loss benefits of multi-ingredient supplements in conjunction with a low-calorie, high-protein diet in young women are unknown. Therefore, the purpose of this study was to investigate the effects of a three-week low-calorie diet with and without supplementation on body composition.

METHODS

Thirty-seven recreationally-trained women (n = 37; age = 27.1 ± 4.2; height = 165.1 ± 6.4; weight = 68.5 ± 10.1; BMI = 25.1 ± 3.4) completed one of the following three-week interventions: no change in diet (CON); a high-protein, low-calorie diet supplemented with a thermogenic, conjugated linoleic acid (CLA), a protein gel, and a multi-vitamin (SUP); or the high-protein diet with isocaloric placebo supplements (PLA). Before and after the three-week intervention, body weight, %Fat via dual X-ray absorptiometry (DXA), segmental fat mass via DXA, %Fat via skinfolds, and skinfold thicknesses at seven sites were measured.

RESULTS

SUP and PLA significantly decreased body weight (SUP: PRE, 70.47 ± 8.01 kg to POST, 67.51 ± 8.10 kg; PLA: PRE, 67.88 ± 12.28 kg vs. POST, 66.38 ± 11.94 kg; p ≤ 0.05) with a greater (p ≤ 0.05) decrease in SUP than PLA or CON. SUP and PLA significantly decreased %Fat according to DXA (SUP: PRE, 34.98 ± 7.05% to POST, 32.99 ± 6.89%; PLA: PRE, 34.22 ± 6.36% vs. POST, 32.69 ± 5.84%; p ≤ 0.05), whereas only SUP significantly decreased %Fat according to skinfolds (SUP: PRE, 27.40 ± 4.09% to POST, 24.08 ± 4.31%; p ≤ 0.05). SUP significantly (p ≤ 0.05) decreased thicknesses at five skinfolds (chest, waist, hip, subscapular, and tricep) compared to PLA, but not at two skinfolds (axilla and thigh).

CONCLUSIONS

The addition of a thermogenic, CLA, protein, and a multi-vitamin to a three-week low-calorie diet improved weight loss, total fat loss and subcutaneous fat loss, compared to diet alone.

The theory and fundamentals of bioimpedance analysis in clinical status monitoring and diagnosis of diseases

Bioimpedance analysis is a noninvasive, low cost and a commonly used approach for body composition measurements and assessment of clinical condition. There are a variety of methods applied for interpretation of measured bioimpedance data and a wide range of utilizations of bioimpedance in body composition estimation and evaluation of clinical status. This paper reviews the main concepts of bioimpedance measurement techniques including the frequency based, the allocation based, bioimpedance vector analysis and the real time bioimpedance analysis systems. Commonly used prediction equations for body composition assessment and influence of anthropometric measurements, gender, ethnic groups, postures, measurements protocols and electrode artifacts in estimated values are also discussed. In addition, this paper also contributes to the deliberations of bioimpedance analysis assessment of abnormal loss in lean body mass and unbalanced shift in body fluids and to the summary of diagnostic usage in different kinds of conditions such as cardiac, pulmonary, renal, and neural and infection diseases.

Running sprint interval training induces fat loss in women

Data on whether sprint interval training (SIT) (repeated supermaximal intensity, short-duration exercise) affects body composition are limited, and the data that are available suggest that men respond more favourably than do women. Moreover, most SIT data involve cycling exercise, and running may differ because of the larger muscle mass involved. Further, running is a more universal exercise type. This study assessed whether running SIT can alter body composition (air displacement plethysmography), waist circumference, maximal oxygen consumption, peak running speed, and (or) the blood lipid profile. Fifteen recreationally active women (age, 22.9 ± 3.6 years; height, 163.9 ± 5.1 cm; mass, 60.8 ± 5.2 kg) completed 6 weeks of running SIT (4 to 6, 30-s "all-out" sprints on a self-propelled treadmill separated by 4 min of rest performed 3 times per week). Training decreased body fat mass by 8.0% (15.1 ± 3.6 to 13.9 ± 3.4 kg, P = 0.002) and waist circumference by 3.5% (80.1 ± 4.2 to 77.3 ± 4.4 cm, P = 0.048), whereas it increased fat-free mass by 1.3% (45.7 ± 3.5 to 46.3 ± 2.9 kg, P = 0.05), maximal oxygen consumption by 8.7% (46 ± 5 to 50 ± 6 mL/(kg·min), P = 0.004), and peak running speed by 4.8% (16.6 ± 1.7 to 17.4 ± 1.4 km/h, P = 0.026). There were no differences in food intake assessed by 3-day food records (P > 0.329) or in blood lipids (P > 0.595), except for a slight decrease in high-density lipoprotein concentration (1.34 ± 0.28 to 1.24 ± 0.24 mmol/L, P = 0.034). Running SIT is a time-efficient strategy for decreasing body fat while increasing aerobic capacity, peak running speed, and fat-free mass in healthy young women.