A Nomogram for the Estimate of Percent Body Fat from Generalized Equations

Abstract

Fifteen well-conditioned college women, who had been thoroughly trained in the correct technique for women's push-ups, were tested for maximal pushing strength in two positions and for the number of complete push-ups they were able to perform at the rate of 41 push-ups per minute. For statistical purposes, calculations of maximal strength for each individual were based upon the average of the recorded maximal arm strengths in the high and low positions plus the average of the weight supported in the high and low positions. The work load was calculated from the distance between the high and low positions, the average supported weight, and the number of push-ups the subject was able to perform until exhausted. A correlation coefficient of .76 was obtained between the calculated maximal strength measures and the work load, indicating a statistically significant positive relationship.     

A comparison of anthropometric and training characteristics of Ironman triathletes and Triple Iron ultra-triathletes

Abstract

We examined differences in anthropometry and training between 64 Triple Iron ultra-triathletes competing over 11.4 km swimming, 540 km cycling, and 126.6 km running, and 71 Ironman triathletes competing over 3.8 km swimming, 180 km cycling, and 42.2 km running. The association of anthropometry and training with race time was investigated using multiple linear regression analysis. The Triple Iron ultra-triathletes were smaller (P < 0.05), had shorter limbs (P < 0.05), a higher body mass index (P < 0.05), and larger limb circumferences (P < 0.01) than the Ironman triathletes. The Triple Iron ultra-triathletes trained for more hours (P < 0.01) and covered more kilometres (P < 0.01), but speed in running during training was slower compared with the Ironman triathletes (P < 0.01). For Triple Iron ultra-triathletes, percent body fat (P = 0.022), training volume per week (P < 0.0001), and weekly kilometres in both cycling (P < 0.0001) and running (P < 0.0001) were related to race time. For Ironman triathletes, percent body fat (P < 0.0001), circumference of upper arm (P = 0.006), and speed in cycling training (P = 0.012) were associated with total race time. We conclude that both Triple Iron ultra-triathletes and Ironman triathletes appeared to profit from low body fat. Triple Iron ultra-triathletes relied more on training volume in cycling and running, whereas speed in cycling training was related to race time in Ironman triathletes.     

The influence of` preseason training phase and training load on body composition and its relationship with physical qualities in professional junior rugby league players

ABSTRACT

This study investigated changes in body composition in relation to training load determined using RPE and duration (sRPE), and its relationship with physical qualities over a preseason period. Sixteen professional academy players (age = 17.2 ± 0.7 years; stature = 179.9 ± 4.9 cm; body mass = 88.5 ± 10.1 kg) participated in the study. Body composition was assessed before and after each training phase and physical qualities assessed at the start and end of preseason. Across the whole preseason period, skinfold thickness, body fat percentage and fat mass were most likely lower (ES = ?0.73 to ?1.00), and fat free mass and lean mass were likely to most likely higher (ES = 0.31 to 0.40). Results indicated that the magnitude of change appeared phase-dependent (ES = ?0.05 to ?0.85) and demonstrated large individual variability. Changes in physical qualities ranged from unclear to most likely (ES = ?0.50 to 0.64). Small to moderate correlations were observed between changes in body composition, and TL with changes in physical qualities. This study suggests training phase and TL can influence a player’s body composition; that large inter-participant variability exists; and that body composition and TL are related to the change in physical qualities.     

Notices

Kinanthropometry III. Proceedings of the VIII Commonwealth and International Conference on Sport, Physical Education, Dance, Recreation and Health. T. Reilly, J. Watkins and J. Borms (eds), E. &; F.N. Spon, London, 1986, xii + 312 pp, £25 (hb), ISBN 0 419 13970 2

Sensible fitness. J.H. Wilmore, Human Kinetics, Champaign, Illinois, USA, 1986, xii + 300 pp, $11.95, ISBN 0 88011 270 0

Running without fear. K.H. Cooper, Bantam Books, London, 1985, 256 pp, £3.95, ISBN 0 553 17356 1

Athletic training and sports medicine. American Academy of Orthopaedic Surgeons, Churchill Livingstone, Chicago, USA, 1986. viii + 602 pp, £40, ISBN 0 89203 002 X

Athletics and the heart. R. Rost, Year Book Medical Publishers Inc., Chicago, 1987, vii+159 pp, £21.50 (pb), ISBN 0 8151 7397 0

Psychology and sociology of sport: current selected research, Volume 1. L.V. Velden and J.M. Humprey (eds), AMS Press, New York, 1986, ix + 237 pp, £49.50 (hb), ISBN 0 404 63401 X     

The importance of accurate site location for skinfold measurement

Abstract

We assessed the importance of accurate site location for skinfold measurement in ten healthy males in a cross-sectional quantitative study. Nine measurements, in a 1-cm grid pattern, centred on each of eight ISAK-specified skinfold sites, were taken three times at each grid point by each of two ISAK Level 4 practitioners using Harpenden skinfold callipers. The presence of significant systematic discrepancy between reliability measures of different skinfold sites and grid points for each of the two testers was determined using P-values. Effect sizes were calculated to show the magnitude of effects. Skinfolds taken at the eight peripheral grid points were generally different from the skinfolds taken at a central ISAK grid point and there was an effect by direction away from the central ISAK point (anterior, posterior, superior or inferior). The subscapular skinfold had the least number of differences (three) and the abdominal had the most (eight). All other skinfold sites showed some variation with most care needed in marking the biceps and triceps skinfold sites. Adherence to identifying, marking, and measuring at the defined site is essential.     

Childhood single skinfold thickness is a better predictor for adult relative fat mass in females than the body mass index: Data from a 30-year longitudinal growth study

Abstract

Information on the prediction of adult relative fat mass (percent body fat,%BF) using measures from pre-pubertal ages and early childhood is scarce. In the present longitudinal study, we assess the development of different anthropometric indicators of percent body fat during childhood, adolescence, and adulthood in 37½-year-old females stratified for low and high percent body fat. Consequently, we study the predictability of percent body fat based on simple anthropometric measurements during childhood and adolescence.

Anthropometric data from the Belgian longitudinal experimental growth study “LEGS” were used. Beginning in 1969, five yearly cohorts of about 100 individuals each (mean age 6 years) were recruited in public kindergartens. Of the original 515 participants (260 males, 255 females) that were measured annually from age 6 to 18 years, 59 males and 60 females agreed to participate in a follow-up study in 2004. During the follow-up measurements, the participants were invited for a body-composition assessment by bioelectrical impedance analysis (BIA). We stratified the participants into low (%BF-BIA < 35%) and high (%BF-BIA≥35%) relative fat mass samples. Pearson correlations were calculated and used as tracking coefficients. Multiple stepwise linear regression was applied with anthropometric variables at each age separately as predictors for adult percent body fat, expressed as%BF-BIA, %BF-Segal, and %BF-D&W (Durnin & Womersley, 1974).

The results indicate that a single skinfold thickness during adolescence is a better predictor for adult percent body fat than adolescent body mass index. Additionally, our results suggest that this holds during childhood as early as from age 8 onwards. The use of single skinfold measurements as predictors for adult adiposity and obesity is supported by other arguments, including: (1) body mass index as a proxy for overweight does not discriminate between fat mass and fat-free mass, and (2) an excess of adipose tissue is more strongly associated with morbidity than the body mass index.     

Monitoring seasonal and long-term changes in test performance in elite swimmers

Abstract

The purpose of this study was to characterize changes and variability in test performance of swimmers within and between seasons over their elite competitive career. Forty elite swimmers (24 male, 16 female) performed a 7×200-m incremental swimming step test several times each 6-month season (10±5 tests, spanning 0.5–6.0?y). Mixed linear modeling provided estimates of percent change in the mean and individual responses (within-athlete variation as a coefficient of variation) for measures based on submaximal performance (fixed 4-mM lactate), maximal performance (the seventh step) and lean mass (from skinfolds and body mass). Submaximal and maximal swim speed increased within each season from pre to taper phase by ～2.2% for females and ～1.5% for males (95% confidence limits ±1.0%), with variable contributions from stroke rate and stroke length. Most of the gains in speed were lost in the off-season, leaving a net average annual improvement of ～1.0% for females and ～0.6% for males (±1.0%). For submaximal and maximal speed, individual variation between phases was ±2.2% and the typical measurement error was ±0.80%. Step test and anthropometric measures can be used to confidently monitor progressions in swimmers in an elite training program within and between seasons.     

Motor coordination,physical activity and fitness as predictors of longitudinal change in adiposity during childhood

Abstract

The purpose of this study was to examine the influence of motor coordination (MC), physical fitness (PF) and physical activity (PA) on the development of subcutaneous adiposity in a sample of children followed longitudinally from 6 to 10 years of age. Participants were 142 girls and 143 boys. Height, weight, and the triceps and subscapular skinfolds were measured annually between the ages of 6 and 10 years. PA was estimated with the Godin–Shephard questionnaire. MC was evaluated with the Körperkoordination Test für Kinder (KTK) test battery, and PF was assessed with four Fitnessgram tests: curl-ups (CU), push-ups (PU), trunk-lifts (TL) and one mile run/walk (MRW). Hierarchical linear modelling with MC, PF items and PA as predictors of the sum of two skinfolds (SKF) was used. The results showed that boys and girls differed significantly in SKF at baseline (girls: 19.7 mm; boys: 16.6 mm). Three PF items (CU, PU and MRW) and MC had a positive influence on SKF. For each unit improvement in CU, PU, MRW and MC, SKF was reduced by 0.06, 0.04, 0.06 and 0.12 mm, respectively. In conclusion, motor coordination, muscular strength and endurance, and aerobic endurance attenuated the accumulation of subcutaneous adipose tissue during childhood.     

Validity of “Generalized” Equations for Body Composition Analysis in Women Athletes

Abstract

Equations by Jackson, Pollock, and Ward (1980) and by Durnin and Womersly (1974) for estimating body density (BD) from skinfolds (SF) purportedly overcome the criticism of “population specificity” by taking into account age and the curvilinear relationship between SFs and BD. Selected equations were validated on 79 women athletes against %fat and fat(kg) measured by underwater weighing. Equations by Sloan, Burt, and Blyth (1962), Wilmore and Behnke (1970), and Katch and McArdle (1973) were also evaluated to compare the newer equations to older ones. The mean estimate of %fat by one equation by Jackson et al. utilizing the sum of triceps, abdomen, suprailiac and thigh SF was the same as the true value (20.1%) and correlated .795 (SEE ± 3.27 total error 3.23). Regression analysis showed it to have acceptable accuracy over the range of sample values (10.3–34.0%). The Durnin-Womersly equations overestimated %fat by 3.9 to 4.4% and were not acceptable. For the older equations, the mean Sloan et al. estimate (20.8 %Fat) was not significantly different from the true value and correlated .779 (SEE ± 3.37 total error 3.47). Regression analysis showed it to overestimate fat in leaner subjects and to underestimate it in fatter ones, making it unacceptable. The Wilmore-Behnke equation overestimated %fat by 4.3%. Equations by Jackson et al., using the sum of triceps, suprailiac and thigh skinfolds, and by Katch and McArdle were shown to be acceptable if the ordinate values were adjusted (1.0994921 to 1.1074921 and 1.08347 to 1.09147 respectively) to account for the higher density of women athletes.     

Efficacy of Skinfold Training Clinics: A Comparison between Clinic Trained and Experienced Testers

Abstract

In an attempt to differentiate more adequately between the terms motor ability and athletic participation in their relationship to some measurable aspects of personality, a group of 167 Pomona College junior and senior male students were classified both as to level of motor ability and participation in athletics and were administered the CPI. Utilizing a total test response derived from the sum of ranks of median scores, low and middle motor ability groups ranked higher in the main effects and within the nonathlete and intramural participation groups, but athletic participation did not appear to have any effect upon the measures studied. The pattern of results suggested an expectation hypothesis wherein higher ratings in the personality inventory might be achieved by groups of subjects who participated at a level which would be “expected” in relation to their motor ability.