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Eric C. Haakonssen, David T. Martin, Louise M. Burke and David G. Jenkins

Body composition in a female road cyclist was measured using dual-energy X-ray absorptiometry (5 occasions) and anthropometry (10 occasions) at the start of the season (Dec to Mar), during a period of chronic fatigue associated with poor weight management (Jun to Aug), and in the following months of recovery and retraining (Aug to Nov). Dietary manipulation involved a modest reduction in energy availability to 30–40 kcal · kg fat-free mass−1 · d−1 and an increased intake of high-quality protein, particularly after training (20 g). Through the retraining period, total body mass decreased (−2.82 kg), lean mass increased (+0.88 kg), and fat mass decreased (−3.47 kg). Hemoglobin mass increased by 58.7 g (8.4%). Maximal aerobic- and anaerobic-power outputs were returned to within 2% of preseason values. The presented case shows that through a subtle energy restriction associated with increased protein intake and sufficient energy intake during training, fat mass can be reduced with simultaneous increases in lean mass, performance gains, and improved health.

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Mathieu L. Maltais, Karine Perreault, Alexandre Courchesne-Loyer, Jean-Christophe Lagacé, Razieh Barsalani and Isabelle J. Dionne

The decrease in resting energy expenditure (REE) and fat oxidation with aging is associated with an increase in fat mass (FM), and both could be prevented by exercise such as resistance training. Dairy consumption has also been shown to promote FM loss in different subpopulations and to be positively associated with fat oxidation. Therefore, we sought to determine whether resistance exercise combined with dairy supplementation could have an additive impact on FM and energy metabolism, especially in individuals with a deficit in muscle mass. Twenty-six older overweight sarcopenic men (65 ± 5 years old) were recruited for the study. They participated in 4 months of resistance exercise and were randomized into three groups for postexercise shakes (control, dairy, and nondairy isocaloric and isoprotein supplement with 375 ml and ~280 calories per shake). Body composition was measured by dual X-ray absorptiometry and REE by indirect calorimetry. Fasting glucose, insulin, leptin, inflammatory profile, and blood lipid profile were also measured. Significant decreases were observed with FM only in the dairy supplement group; no changes were observed for any other variables. To conclude, FM may decrease without changes in metabolic parameters during resistance training and dairy supplementation with no caloric restriction without having any impact on metabolic properties. More studies are warranted to explain this significant decrease in FM.

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Adam J. Zemski, Shelley E. Keating, Elizabeth M. Broad and Gary J. Slater

), distinct differences in body composition exist. Forwards have consistently been shown to be heavier, taller, and possess more fat-free mass (FFM) and fat mass (FM), whereas backs display proportionally lower body fat ( Lees et al., 2017 ; Zemski et al., 2015 ). Optimal body composition assists athletes in

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Adam J. Zemski, Shelley E. Keating, Elizabeth M. Broad, Damian J. Marsh, Karen Hind and Gary J. Slater

). Increases in LM can influence the power-to-weight ratio of players, thus increasing the potential to proliferate momentum, strength, power, and speed ( Bell et al., 2005 ). Excess fat mass (FM) has negative implications for thermoregulation ( Selkirk & McLellan, 2001 ) and concurrently increases energy

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Felipe Fossati Reichert, Jonathan Charles Kingdom Wells, Ulf Ekelund, Ana Maria Baptista Menezes, Cesar Gomes Victora and Pedro C. Hallal

Background:

Physical activity may influence both fat and lean body mass. This study investigated the association between physical activity in children between the ages of 11 and 13 years and both fat and lean mass.

Methods:

A subsample of the 1993 Pelotas (Brazil) Birth Cohort was visited in 2004–2005 and 2006–2007. Physical activity was estimated through standardized questionnaires. Body composition (ie, fat and lean mass) was measured using deuterium dilution. Those with moderate-to-vigorous activity greater than 420 min/wk were classified as active, and physical activity trajectory was defined as being above or below the cutoff at each visit.

Results:

Four hundred eighty-eight adolescents (51.8% boys) were evaluated. The mean difference in fat mass in boys and girls who reported ≥ 420 min/wk of physical activity in both visits compared with those who were consistently inactive was –4.8 kg (P ≤ .001). There was an inverse association between physical activity and fat mass among boys in both crude and confounder-adjusted analyses, whereas for girls, the association was evident only in the crude analysis. There was no significant association between physical activity and lean mass.

Conclusion:

Physical activity may contribute to tackling the growing epidemic of adolescent obesity in low- and middle-income countries.

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Darryn S. Willoughby

This study examined 12 wk of resistance training and cystoseim canariensis supplementation on serum levels of myostatin and follistatin-like related gene (FLRG) and muscle strength and body composition. Twenty-two untrained males were randomly assigned to a placebo (PLC) or myostatin binder (MYO) group in a double-blind fashion. Blood was obtained before and after 6 and 12 wk of training. PLC and MYO trained thrice weekly using 3 sets of 6 to 8 repetitions at 85% to 90% 1 repetition maximum. MYO ingested 1200 mg/d of cystoseim canariensis. Data were analyzed with 2-way ANOVA. After training, total body mass, fat-free mass, muscle strength, thigh volume/mass, and serum myostatin and FLRG increased for both groups (P < 0.05); however, there were no differences between groups (P > 0.05). Twelve wk of heavy resistance training and 1200 mg/d of cystoseim canariensis supplementation appears ineffective at inhibiting serum myostatin and increasing muscle strength and mass or decreasing fat mass.

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Danielle R. Bouchard, K. Ashlee McGuire, Lance Davidson and Robert Ross

One hundred forty-six abdominally obese adults age 60–80 yr were studied to investigate the interaction between cardiorespiratory fitness (CRF) and obesity on functional limitation. Obesity was determined by fat mass (FM), CRF was determined by a maximal treadmill test, and functional limitation was based on 4 different tasks that are predictive of subsequent disability. Both FM (r = –.34, p ≤ .01) and CRF (r = .54, p ≤ .01) were independently associated with functional limitation in bivariate analysis. After further control for sex, age, and the interaction term (CRF × FM), FM was no longer independently associated with functional limitation (p = .10). Analyses were also based on sex-specific tertiles of FM and CRF. The referent group demonstrated significantly lower functional limitation than the low-CRF/low-FM and the low-CRF/high-FM groups (both p ≤ .05). These results highlight the value of recommending exercise for abdominally obese adults.

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Asunción Ferri-Morales, Marcus Vinicius Nascimento-Ferreira, Dimitris Vlachopoulos, Esther Ubago-Guisado, Ana Torres-Costoso, Augusto Cesar F. De Moraes, Alan R. Barker, Luis A. Moreno, Vicente Martínez-Vizcaino and Luis Gracia-Marco

specific density in fat mass ( 33 ). Air-displacement plethysmography (ADP) is an alternative method that has been extensively used worldwide to calculate body volume by measuring the volume of air displaced by the participant inside the chamber ( 22 ). Nunez et al ( 27 ) found a high correlation between

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Kevin Till, Ben Jones, John O’Hara, Matthew Barlow, Amy Brightmore, Matthew Lees and Karen Hind

Purpose:

To compare the body size and 3-compartment body composition between academy and senior professional rugby league players using dual-energy X-ray absorptiometry (DXA).

Methods:

Academy (age 18.1 ± 1.1 y, n = 34) and senior (age 26.2 ± 4.6 y, n = 63) rugby league players received 1 total-body DXA scan. Height, body mass, and body-fat percentage alongside total and regional fat mass, lean mass, and bone mineral content (BMC) were compared. Independent t tests with Cohen d effect sizes and multivariate analysis of covariance (MANCOVA), controlling for height and body mass, with partial eta-squared (η2) effect sizes, were used to compare total and regional body composition.

Results:

Senior players were taller (183.2 ± 5.8 vs 179.2 ± 5.7 cm, P = .001, d = 0.70) and heavier (96.5 ± 9.3 vs 86.5 ± 9.0 kg, P < .001, d = 1.09) with lower body-fat percentage (16.3 ± 3.7 vs 18.0 ± 3.7%, P = .032, d = 0.46) than academy players. MANCOVA identified significant overall main effects for total and regional body composition between academy and senior players. Senior players had lower total fat mass (P < .001, η 2 = 0.15), greater total lean mass (P < .001, η 2 = 0.14), and greater total BMC (P = .001, η 2 = 0.12) than academy players. For regional sites, academy players had significantly greater fat mass at the legs (P < .001, η 2 = 0.29) than senior players.

Conclusions:

The lower age, height, body mass, and BMC of academy players suggest that these players are still developing musculoskeletal characteristics. Gradual increases in lean mass and BMC while controlling fat mass is an important consideration for practitioners working with academy rugby league players, especially in the lower body.

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Kaelin C. Young, Kristina L. Kendall, Kaitlyn M. Patterson, Priyanka D. Pandya, Ciaran M. Fairman and Samuel W. Smith

Purpose:

To assess changes in body composition, lumbar-spine bone mineral density (BMD), and rowing performance in collegelevel rowers over a competition season.

Methods:

Eleven Division I college rowers (mean ± SD 21.4 ± 3.7 y) completed 6 testing sessions throughout the course of their competition season. Testing included measurements of fat mass, bone-free lean mass (BFLM), body fat (%BF), lumbar-spine BMD, and 2000-m time-trial performance. After preseason testing, rowers participated in a periodized training program, with the addition of resistance training to the traditional aerobic-training program.

Results:

Significant (P < .05) improvements in %BF, total mass, and BFLM were observed at midseason and postseason compared with preseason. Neither lumbar-spine BMD nor BMC significantly changed over the competitive season (P > .05). Finally, rowing performance (as measured by 2000-m time and average watts achieved) significantly improved at midseason and postseason compared with preseason.

Conclusion:

Our results highlight the efficacy of a seasonal concurrent training program serving to improve body composition and rowing performance, as measured by 2000-m times and average watts, among college-level rowers. Our findings offer practical applications for coaches and athletes looking to design a concurrent strength and aerobic training program to improve rowing performance across a season.