High Energy Flux Mediates the Tonically Augmented β-Adrenergic Support of Resting Metabolic Rate in Habitually Exercising Older Adults

Bell, Christopher; Day, Danielle S.; Jones, P. P.; Christou, Demetra D.; Petitt, Darby S.; Osterberg, Kris L.; Melby, Christopher L.; Seals, Douglas R.

doi:10.1210/jc.2003-032146

Cited by 50 publications

(53 citation statements)

References 32 publications

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“…Efferent multiunit postganglionic MSNA was measured from the peroneal nerve via standard microneurography procedures as previously described (Bell et al 2003(Bell et al , 2004. Briefly, two tungsten microelectrodes (FHC, Inc., Bowdoin, ME, USA) were inserted into the lower limb distal to the knee: one impaled the peroneal nerve, while the other served as a reference electrode and was placed nearby, but not in the nerve.…”

Section: Methodsmentioning

confidence: 99%

Short-term sympathoadrenal inhibition augments the thermogenic response to β-adrenergic receptor stimulation

Newsom

Richards²,

Johnson³

et al. 2010

Journal of Endocrinology

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Sedentary behavior is associated with an attenuated thermogenic response to b-adrenergic receptor (b-AR) stimulation, an important regulator of energy expenditure (EE) in humans. Chronic stimulation of b-ARs, via heightened activity of the sympathoadrenal system, leads to diminished b-AR function. We have investigated the hypothesis that the thermogenic response of sedentary adults to b-AR stimulation will be increased during short-term sympathoadrenal inhibition. Using a randomly ordered, repeated measures study design, resting EE (REE; indirect calorimetry, ventilated hood technique) and the % increase in EE above REE (%DEE) during acute i.v. isoproterenol administration (nonselective b-AR agonist; 6, 12, and 24 ng/kg fat-free mass per min) were determined in 16 sedentary adults (nine females and seven males, 25G1 years, body mass index: 26 . 1G0 . 9 kg/m 2 , maximal oxygen uptake: 40G2 ml/kg per min (meanGS.E.M.)) in the basal state and on the 6th day of transdermal clonidine administration (centrally acting a2-AR agonist; 0 . 2 mg/day).Relative to baseline, clonidine inhibited sympathoadrenal activity, as evidenced by decreased plasma norepinephrine concentration (1 . 04G0 . 13 vs 0 . 34G0 . 03 nmol/l; P!0 . 001), skeletal muscle sympathetic nerve activity (22 . 5G3 . 8 vs 8 . 5 G1 . 9 bursts/min; PZ0 . 003), and resting heart rate (63G2 vs 49G1 beats/min; P!0 . 001). Sympathoadrenal inhibition decreased REE (6510G243 vs 5857G218 kJ/day; P!0 . 001), increased respiratory exchange ratio (0 . 84G0 . 01 vs 0 . 86 G0 . 01; PZ0 . 03), and augmented the thermogenic response to b-AR stimulation (%DEE: 11G2, 16G2, and 24G2 vs 14G1, 20G2, and 31G2; PZ0 . 04). These data demonstrate that in sedentary humans, short-term inhibition of sympathoadrenal activity increases the thermogenic response to b-AR stimulation, an important determinant of EE and hence energy balance.

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Section: Methodsmentioning

confidence: 99%

Short-term sympathoadrenal inhibition augments the thermogenic response to β-adrenergic receptor stimulation

Newsom

Richards²,

Johnson³

et al. 2010

Journal of Endocrinology

Self Cite

View full text Add to dashboard Cite

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“…Although RMR decreases during energy restriction, there is evidence that RMR is preserved when weight loss is caused by exercise 66 , and recent data suggest that RMR is greater in adults who perform regular aerobic exercise than their sedentary peers. [67][68][69][70][71][72] Compensatory changes can also occur in levels of spontaneous physical activity outside the exercise period of the study. Donnelly and Smith 27 have reported anecdotal observations which suggest that when an exercise program is initiated, spontaneous physical activity might temporarily decline because of fatigue, but returns to baseline levels at some time point and might eventually increase to above baseline levels as fitness increases.…”

Section: Gaps In Our Knowledge Of Physical Activity and Weight Lossmentioning

confidence: 99%

The role of physical activity in producing and maintaining weight loss

2007

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SummaryThe majority of randomized, controlled trials (RCTs) show only modest weight loss with exercise intervention alone, and slight increases in weight loss when exercise intervention is added to dietary restriction. In most RCTs, the energy deficit produced by the prescribed exercise is far smaller than that usually produced by dietary restriction. In prospective studies that prescribed high levels of exercise, enrolled individuals achieved substantially greater weight losscomparable to that obtained after similar energy deficits were produced by caloric restriction. High levels of exercise might, however, be difficult for overweight or obese adults to achieve and sustain. RCTs examining exercise and its effect on weight-loss maintenance demonstrated mixed results; however, weight maintenance interventions were usually of limited duration and long-term adherence to exercise was problematic. Epidemiologic, cross-sectional, and prospective correlation studies suggest an essential role for physical activity in weight-loss maintenance, and post hoc analysis of prospective trials shows a clear dose-response relationship between physical activity and weight maintenance. This article reviews the role of physical activity in producing and maintaining weight loss. We focus on prospective, RCTs lasting at least 4 months; however, other prospective trials, meta-analyses and large systematic reviews are included. Limitations in the current body of literature are discussed.

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“…PA, on the other hand, manipulates energy expenditure and regulates the use of fuels. When prolonged strenuous PA is performed on a regular basis, it causes an increase in overall energy turnover 1 and leads either to loss of body weight, or to a need for an increase in food intake. 2 Nevertheless, many questions remain open in that regard.…”

Section: Introductionmentioning

confidence: 99%

Effects of physical activity on food intake

Melzer¹,

Kayser²,

Saris³

et al. 2005

Clinical Nutrition

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SummaryThe understanding of the effect of physical activity (PA) on food intake is imperative for considering PA as an additional tool for prevention and treatment of many diseases. Prolonged strenuous PA performed on a regular basis causes an increase in overall energy turnover, and leads either to loss of body weight, or to an increased food intake. When leading to loss of body weight, PA may be used as a therapeutic adjunct in the treatment of obesity. When increasing food intake to compensate for increased energy expenditure and maintaining body weight, PA, by increasing intake of other constituents of food like minerals and vitamins, may contribute to micronutrient deficiency coverage. However, the type of activity, as well as body composition of the individuals engaging in sport, play an important role in food intake regulation and its changes with time. Some studies indicate that shortterm exercise does not have the same effect on food intake as long-term exercise and that eventual increase in food intake due to increased PA does not follow the same pattern in obese as in lean individuals. To better understand the relationship between PA on food intake, current findings on this topic will be summarized in this paper.

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High Energy Flux Mediates the Tonically Augmented β-Adrenergic Support of Resting Metabolic Rate in Habitually Exercising Older Adults

Cited by 50 publications

References 32 publications

Short-term sympathoadrenal inhibition augments the thermogenic response to β-adrenergic receptor stimulation

Short-term sympathoadrenal inhibition augments the thermogenic response to β-adrenergic receptor stimulation

The role of physical activity in producing and maintaining weight loss

Effects of physical activity on food intake

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