Maximal oxygen uptake (V̇O2max), fractional utilization of V̇O2max during running, and running economy (RE) are crucial factors for running success for all endurance athletes. Although evidence is limited, investigations of these key factors indicate that East Africans’ superiority in distance running is largely due to a unique combination of these factors. East African runners appear to have a very high level of RE most likely associated, at least partly, with anthropometric characteristics rather than with any specific metabolic property of the working muscle. That is, evidence suggest that anthropometrics and body composition might have important parameters as determinants of superior performance of East African distance runners. Regrettably, this role is often overlooked and mentioned as a descriptive parameter rather than an explanatory parameter in many research studies. This brief review article provides an overview of the evidence to support the critical role anthropometrics and body composition has on the distance running success of East African athletes. The structural form and shape of these athletes also has a downside, because having very low BMI or body fat increases the risk for relative energy deficiency in sport (RED-S) conditions in both male and female runners, which can have serious health consequences.
Martin Mooses and Anthony C. Hackney
Alisa Nana, Gary J. Slater, Arthur D. Stewart and Louise M. Burke
Dual energy X-ray absorptiometry (DXA) is rapidly becoming more accessible and popular as a technique to monitor body composition, especially in athletic populations. Although studies in sedentary populations have investigated the validity of DXA assessment of body composition, few studies have examined the issues of reliability in athletic populations and most studies which involve DXA measurements of body composition provide little information on their scanning protocols. This review presents a summary of the sources of error and variability in the measurement of body composition by DXA, and develops a theoretical model of best practice to standardize the conduct and analysis of a DXA scan. Components of this protocol include standardization of subject presentation (subjects rested, overnight-fasted and in minimal clothing) and positioning on the scanning bed (centrally aligned in a standard position using custom-made positioning aids) as well as manipulation of the automatic segmentation of regional areas of the scan results. Body composition assessment implemented with such protocol ensures a high level of precision, while still being practical in an athletic setting. This ensures that any small changes in body composition are confidently detected and correctly interpreted. The reporting requirements for studies involving DXA scans of body composition include details of the DXA machine and software, subject presentation and positioning protocols, and analysis protocols.
Robert H. DuRant, William O. Thompson, Maribeth Johnson and Tom Baranowski
This follow-up investigation examined the relationship among observed time of television watching, physical activity, and body composition in 5- to 6-year-old children previously studied 2 years ago. Activity level on school and nonschool days was measured with the Children’s Activity Rating Scale. Television watching time was assessed by direct observation, and body composition was measured with the body mass index, skinfold thicknesses, and waist/hip ratio. Television watching behavior, which increased from the earlier study, was not associated with body composition. Physical activity was lower during television watching than nontelevision watching time.
Manny Felix, Jeff McCubbin and Janet Shaw
Many women with mild to moderate mental retardation (MMR) exhibit low levels of physical activity, muscle strength, and muscle mass, which place these individuals at risk for osteoporosis. Bone mineral density (BMD), the primary index of osteoporosis, of the femoral neck and the whole body was measured in premenopausal women with (M age = 28.14 ± 8.43) and without (M age = 29.64 ± 10.86) mental retardation (MMR and NMR, respectively). Multivariate analyses revealed no differences (p > .05) between groups (MMR = 16, NMR = 16) for BMD values. Significant differences existed (p < .05) between groups on body composition and muscle strength variables. In the MMR group, significant positive relationships (p < .05) were found between lean muscle mass and both femoral neck (r = .74) and whole body (r = .81) BMD. Unaccounted lifestyle factors may have contributed to nonsignificant BMD values between groups.
Emmanuel Van Praagh, Nicole Fellmann, Mario Bedu, Guy Falgairette and Jean Coudert
This study was done to determine the extent to which body composition accounts for differences in anaerobic characteristics between 12-year-old girls and boys. Peak leg power (PP), mean leg power (MP), percent body fat, fat free mass (FFM), and lean thigh volume (LTV) were determined by various tests. Pubertal stages and salivary testosterone concentration (in boys) were used to assess sexual maturation. Laboratory anaerobic indices were compared with performances in two running tests. Blood samples were taken for lactate determination. Absolute PP and MP outputs were similar in both sexes and were better correlated with LTV in girls, whereas in boys both PP and MP were highly correlated with FFM. Although nonsignificant gender difference in lean tissue was observed, PP and MP when corrected for LTV were significantly greater in boys than in girls. Factors other than the amount of lean muscle mass should be considered in explaining the gender differences in PP and MP in early pubertal children.
Phillip C. Usera, John T. Foley and Joonkoo Yun
The purpose of this study was to cross-validate skinfold and anthropometric measurements for individuals with Down syndrome (DS). Estimated body fat of 14 individuals with DS and 13 individuals without DS was compared between criterion measurement (BOP POD®) and three prediction equations. Correlations between criterion and field-based tests for non-DS group and DS groups ranged from .81 – .94 and .11 – .54, respectively. Root-Mean-Squared-Error was employed to examine the amount of error on the field-based measurements. A MANOVA indicated significant differences in accuracy between groups for Jackson’s equation and Lohman’s equation. Based on the results, efforts should now be directed toward developing new equations that can assess the body composition of individuals with DS in a clinically feasible way.
Richard B. Kreider, Robert Klesges, Karen Harmon, Pamela Grindstaff, Leigh Ramsey, Daryll Bullen, Larry Wood, Yuhua Li and Anthony Almada
This study examined the effects of ingesting nutritional supplements designed to promote lean tissue accretion on body composition alterations during resistance training. Twenty-eight resistance-trained males blindly supplemented their diets with maltodextrin (M), Gainers Fuel® 1000 (GF), or Phosphagain™ (P). No significant differences were observed in absolute or relative total body water among groups. Energy intake and body weight significantly increased in all groups combined throughout the study with no group or interaction differences observed. Dual energy x-ray absorptiometry-determined body mass significantly increased in each group throughout the study with significantly greater gains observed in the GF and P groups. Lean tissue mass (excluding bone) gain was significantly greater in the P group, while fat mass and percent body fat were significantly increased in the GF group. Results indicate that total body weight significantly increased in each group and that P supplementation resulted in significantly greater gains in lean tissue mass during resistance training.
Claudia D’Alessandro, Ester Morelli, Irene Evangelisti, Fabio Galetta, Ferdinando Franzoni, Donatella Lazzeri, Marina Piazza and Adamasco Cupisti
The aim of this study was to investigate the body composition and dietary intake of competitive club-level rhythmic gymnasts, who represent the larger cohort of the sport’s practitioners. Fifty-five rhythmic gymnasts and 55 nonathlete females (13–19 years of age) were seen individually to collect a dietary recall and to take anthropometric data and bioelectric-impedance analysis. Gymnasts had lower body-mass index and lesser skinfold thickness, although middle arm-muscle circumference was similar in the 2 groups. Gymnasts had lower body-fat measures but normal levels of fat-free mass (FFM) and body-cellular mass. Gymnasts had better dietary habits than the age-matched controls. Low levels of calcium, phosphorous, iron, and zinc and a disparity between reported energy intake and estimated energy requirement were observed in both groups.
Tanja Hechler, Elizabeth Rieger, Stephen Touyz, Pierre Beumont, Guy Plasqui and Klaas Westerterp
The study aimed to compare differences in physical activity, the relationship between physical activity and body composition, and seasonal variation in physical activity in outpatients with anorexia nervosa (AN) and healthy controls. Physical activity (CM-AMT) and time spent in different intensities of 10 female individuals with AN and 15 female controls was assessed across three seasons along with the percentage body fat. The two groups did not differ in their physical activity and both demonstrated seasonal variation. The percentage body fat of individuals with AN, but not that of the controls, was negatively related to CM-AMT and time spent in low-moderate intesnity acitivy (LMI). Seasonal variation in physical activity emerged with increases in engagement in LMI during the summer period for both groups. Possible interpretations of the finding that decreased physical activity was related to a normalization of percentage body fat in the individuals with AN are discussed and implications for treatment are highlighted.
Kate Lambourne, Richard Washburn, Jaehoon Lee, Jessica L. Betts, David Thomas, Bryan Smith, Cheryl Gibson, Debra Kay Sullivan and Joseph Donnelly
Fluid milk consumed in conjunction with resistance training (RT) provides additional protein and calcium, which may enhance the effect of RT on body composition. However, the literature on this topic is inconsistent with limited data in adolescents. Therefore, we examined the effects of a supervised RT program (6 mo, 3 d/wk, 7 exercises, 40–85% 1-repetition maximum) with daily milk supplementation (24 oz/day, one 16-oz dose immediately post-RT) on weight, fat mass (FM), and fat-free mass (FFM) assessed via dual-energy X-ray absorptiometry (baseline, 3 mo, 6 mo) in a sample of middle-school students who were randomly assigned to 1 of 3 supplement groups: milk, isocaloric carbohydrate (100% fruit juice), or water (control). Thirty-nine boys and 69 girls (mean age = 13.6 yr, mean BMI percentile = 85th) completed the study: milk n = 36, juice n = 34, water n = 38. The results showed no significant differences between groups for change in body weight (milk = 3.4 ± 3.7 kg, juice = 4.2 ± 3.1 kg, water = 2.3 ± 2.9 kg), FM (milk = 1.1 ± 2.8 kg, juice = 1.6 ± 2.5 kg, water = 0.4 ± 3.6 kg), or FFM (milk = 2.2 ± 1.9 kg, juice = 2.7 ± 1.9 kg, water = 1.7 ± 2.9 kg) over 6 mo. FFM accounted for a high proportion of the increased weight (milk = 62%, juice = 64%, water = 74%). These results from a sample of predominantly overweight adolescents do not support the hypothesis that RT with milk supplementation enhances changes in body composition compared with RT alone.