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Eleni Michopoulou, Alexandra Avloniti, Antonios Kambas, Diamanda Leontsini, Maria Michalopoulou, Symeon Tournis and Ioannis G. Fatouros

This study determined dietary intake and energy balance of elite premenarcheal rhythmic gymnasts during their preseason training. Forty rhythmic gymnasts and 40 sedentary age-matched females (10–12 yrs) participated in the study. Anthropometric profile and skeletal ages were determined. Dietary intake and physical activity were assessed to estimate daily energy intake, daily energy expenditure, and resting metabolic rate. Groups demonstrated comparable height, bone age, pubertal development, resting metabolic rate. Gymnasts had lower body mass, BMI, body fat than age-matched controls. Although groups demonstrated comparable daily energy intake, gymnasts exhibited a higher daily energy expenditure resulting in a daily energy deficit. Gymnasts also had higher carbohydrate intake but lower fat and calcium intake. Both groups were below the recommended dietary allowances for fiber, water, calcium, phosphorus and vitamin intake. Gymnasts may need to raise their daily energy intake to avoid the energy deficit during periods of intense training.

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R. Scott Van Zant

Maintenance of a healthy body weight results from equating total enegy intake to total energy expenditure (resting metabolic rate, RMR, the thermic effect of feeding, TEF; the thermic effect of activity, TEA, and adaptive thermogenesis, AT). Dietary quantity and composition and acute and chrvnic exercise have been shown to influence all components of total energy expenditure. This paper reviews the effects of exercise and diet on energy expenditure and, ultimately, energy balance. Overnutrition increases RMR and TEF while undernutrition decreases them. Carbohydrate and protein oxidation is closely tied to intake whereas fat oxidation does not closely parallel fat intake. Thus excess fat intake is likely to lead to fat storage. Acute endurance exercise at >70% VO2max increases postexercise RMR and TEF. Chronic exercise training may increase RMR while also increasing TEF. Review of the research indicates that energy balance may best be achieved by consuming an energy appropriate, low fat diet complemented by endurance exercise.

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Cynthia A. Gillette, Richard C. Bullough and Christopher L. Melby

Postexercise energy metabolism was examined in male subjects age 22-35 years in response to three different treatments: a strenuous bout of resistive exercise (REx), a bout of stationary cycling (AEx) at 50% peak VO2, and a control condition (C) of quiet sitting. Resting metabolic rate (RMR) was measured the morning of and the morning following each condition. Recovery oxygen consumption (RcO2) was measured for 5 hr following each treatment. Total 5-hr RcO2 was higher for the REx treatment relative to both AEx and C, with the largest treatment differences occurring early during recovery. There were no large treatment differences in postexercise respiratory exchange ratio values, except for the first hour of recovery following REx. RMR measured 14.5 hr postexercise for the REx condition was significantly elevated compared to C. These results suggest that strenuous resistive exercise results in a greater excess postexercise oxygen consumption compared to steady-state endurance exercise of similar estimated energy cost.

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Jennifer Gornall and Rudolph G. Villani

The primary aim was to investigate whether the reduction in resting metabolic rate (RMR) and fat free mass (FFM) associated with a short-term very low kilojoule diet (VLKD) is altered by concurrent resistance exercise. Twenty overweight, premenopausal women were pair matched on body surface area and randomly assigned to either diet only (3,400 kJ/day) or diet combined with resistance training. Before and after 4 weeks of treatment, RMR was assessed by indirect calorimetry; total body mass (TBM), FFM, and fat mass (FM) by dual energy x-ray absorptiometry; total body water (TBW) by bioelectrical impedance; and strength by a weight-lifting test. Both groups had significantly lower TBM, FFM, FM, TBW, absolute RMR, and RMR, with FFM as the covariate, in the posttests than the pretests with no significant differences between groups. It was concluded that 4 weeks of resistance training did not prevent or reduce the decline in FFM and RMR observed with a VLKD.

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Douglas R. Seals, Kevin D. Monahan, Christopher Bell, Hirofumi Tanaka and Pamela P. Jones

Tonic vagal modulation of cardiac period (R-R interval) decreases with advancing age, but is greater in middle-aged and older adults who habitually perform aerobic exercise compared with their sedentary peers. Cardiovagal baroreflex sensitivity also declines markedly with age in sedentary adults but only 50% as much in regularly exercising adults. In previously sedentary middle-aged and older adults, a 3-month program of moderate aerobic exercise increases cardiovagal baroreflex sensitivity by 25%. Tonic (basal) sympathetic nervous system (SNS) activity increases with advancing age in both sedentary and habitually exercising adults. Despite this, SNS b-adrenergic support of energy metabolism (resting metabolic rate-RMR) declines with age in sedentary individuals. However, SNS b-adrenergic support of RMR is maintained with age inenduranceexercise-trainedadultsandthereforeismuchgreaterinmiddle-aged and older individuals who exercise regularly compared with their sedentary peers. Thus, regular aerobic (endurance) exercise modulates selective age associated impairments in autonomic nervous system-physiological function.

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Lisa H. Colbert, Charles E. Matthews, Dale A. Schoeller, Thomas C. Havighurst and KyungMann Kim

This study examined the intensity of activity contributing to physical activity energy expenditure in older adults. In 57 men and women aged ≥ 65, total energy expenditure (TEE) was measured using doubly labeled water and resting metabolic rate was measured using indirect calorimetry to calculate a physical activity index (PAI). Sedentary time and physical activity of light and moderate to vigorous (mod/vig) intensity was measured using an accelerometer. The subjects were 75 ± 7 yrs (mean ± SD) of age and 79% female. Subjects spent 66 ± 8, 25 ± 5, and 9 ± 4% of monitor wear time in sedentary, light, and mod/vig activity per day, respectively. In a mixture regression model, both light (β = 29.6 [15.6–43.6, 95% CI]), p < .001) and mod/vig intensity activity (β = 28.7 [7.4−50.0, 95% CI]), p = .01) were strongly associated with PAI, suggesting that both light and mod/vig intensity activities are major determinants of their physical activity energy expenditure.

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Jeffer Eidi Sasaki, Cheryl A. Howe, Dinesh John, Amanda Hickey, Jeremy Steeves, Scott Conger, Kate Lyden, Sarah Kozey-Keadle, Sarah Burkart, Sofiya Alhassan, David Bassett Jr and Patty S. Freedson

Background:

Thirty-five percent of the activities assigned MET values in the Compendium of Energy Expenditures for Youth were obtained from direct measurement of energy expenditure (EE). The aim of this study was to provide directly measured EE for several different activities in youth.

Methods:

Resting metabolic rate (RMR) of 178 youths (80 females, 98 males) was first measured. Participants then performed structured activity bouts while wearing a portable metabolic system to directly measure EE. Steady-state oxygen consumption data were used to compute activity METstandard (activity VO2/3.5) and METmeasured (activity VO2/measured RMR) for the different activities.

Results:

Rates of EE were measured for 70 different activities and ranged from 1.9 to 12.0 METstandard and 1.5 to 10.0 METmeasured.

Conclusion:

This study provides directly measured energy cost values for 70 activities in children and adolescents. It contributes empirical data to support the expansion of the Compendium of Energy Expenditures for Youth.

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Yong Gao, Haichun Sun, Jie Zhuang, Jian Zhang, Lynda Ransdell, Zheng Zhu and Siya Wang

Background:

This study determined the metabolic equivalents (METs) of several activities typically performed by Chinese youth.

Methods:

Thirty youth (12 years) performed 7 activities that reflected their daily activities while Energy Expenditure (EE) was measured in a metabolic chamber.

Results:

METs were calculated as activity EE divided by participant’s measured resting metabolic rate. A MET value ranging from 0.8 to 1.2 was obtained for sleeping, watching TV, playing computer games, reading and doing homework. Performing radio gymnastics had a MET value of 2.9. Jumping rope at low effort required 3.1 METs. Except for watching TV, METs for other activities in this study were lower than Youth Compendium values.

Conclusions:

The results provide empirical evidence for more accurately assessing EE of activities commonly performed by Chinese youth. This is the first study to determine METs for radio gymnastics and jump rope in Chinese youth.

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Lance Ratcliff, Sareen S. Gropper, B. Douglas White, David M. Shannon and Kevin W. Huggins

This study compared type of habitual exercise and meal form on diet-induced thermogenesis (DIT) in 29 men age 19–28 yr. Resting metabolic rate (RMR) and DIT response to solid-meal (bar) vs. liquid-meal (shake) ingestion were measured via indirect calorimetry; classifications were sedentary (n = 9), endurance trained (n = 11), or resistance trained (n = 9). Height, weight, and body composition (using bioelectrical impedance) were measured for each subject. Energy expenditure was determined before and every 30 min after meal consumption for 210 min. RMR was significantly (p = .045) higher in the endurance- and resistance-trained groups. However, when expressed per kilogram fat-free mass (FFM; relative RMR), differences were not significant. Both DIT (kcal/min) and relative DIT (kcal · min−1 · kg FFM−1) significantly increased with time (p < .0001) from RMR for each meal form. There was no significant exercise-group effect on DIT or relative DIT. There was a significant (p = .012) effect of meal form on DIT; shakes elicited a higher DIT. This significant difference was not found for relative DIT. There was a significant interaction between group and meal form for DIT (p = .008) and relative DIT (p < .0001). Shakes elicited a significantly greater DIT (p = .0002) and relative DIT (p = .0001) in the resistance-trained group. In the sedentary group, relative DIT from shakes was significantly lower than from bars (p = .019). In conclusion, habitual exercise appears to increase RMR, and meal form may impart changes in relative DIT depending on exercise status.

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George Wilson, Neil Chester, Martin Eubank, Ben Crighton, Barry Drust, James P. Morton and Graeme L. Close

Professional jockeys are unique among weight-making athletes, as they are often required to make weight daily and, in many cases, all year-round. Common methods employed by jockeys include dehydration, severe calorie restriction, and sporadic eating, all of which have adverse health effects. In contrast, this article outlines a structured diet and exercise plan, employed by a 22-yr-old professional National Hunt jockey in an attempt to reduce weight from 70.3 to 62.6 kg, that does not rely on any of the aforementioned techniques. Before the intervention, the client’s typical daily energy intake was 8.2 MJ (42% carbohydrate [CHO], 36% fat, 22% protein) consumed in 2 meals only. During the 9-wk intervention, daily energy intake was approximately equivalent to resting metabolic rate, which the athlete consumed as 6 meals per day (7.6 MJ, 46% CHO, 19% fat, 36% protein). This change in frequency and composition of energy intake combined with structured exercise resulted in a total body-mass loss of 8 kg, corresponding to reductions in body fat from 14.5% to 9%. No form of intentional dehydration occurred throughout this period, and mean urine osmolality was 285 mOsm/kg (SD 115 mOsm/kg). In addition, positive changes in mood scores (BRUMS scale) also occurred. The client was now able to ride light for the first time in his career without dehydrating, thereby challenging the cultural practices inherent in the sport.