Relationship between basal metabolic rate body mass and surface area

Resting metabolic rate, weight, surface area and body composition in obese women.

relationship between basal metabolic rate body mass and surface area

The scaling of surface area, A, with the radius, R, goes as A~R2. relationship between the resting metabolic energy requirement per unit mass (B/M) and orders of magnitudes of body size and widely differing phylogenetic groups the rates. in a relationship of the form BMR = aWb where W is body mass. influence of volume and surface area boundary constraints and thus has a. Interest in the relationship between body mass and metabolic rate can .. Smaller mammals have a higher surface area to volume ratio and all.

The resting energy demand of organisms has recently been compared among more than different organisms spanning over 20 orders of magnitude in mass! In contrast to the Kleiber law prediction, this recent work found a relatively small range of variation with the vast majority of organisms having power requirements lying between 0. Further evidence for breaking of Kleiber scaling was provided recently for protists and prokaryotes J.

The metabolic rate of an organism is condition dependent, and thus should be strictly defined if one wants to make an honest comparison across organisms. The most extreme example we are aware of is that bees in flight increase their oxygen consumption and thus their energy consumption by about fold in comparison to resting conditions BNID Similarly, humans taking part in the strenuous Tour de France consume close to 10, kcal a day, about five times the normal resting value.

It is most common to refer to the resting metabolic rate, which operationally means the animal is not especially active but well fed.

Resting metabolic rate, weight, surface area and body composition in obese women.

As the alert reader can imagine, it is not easy to ensure rest for all animals, think of an orca killer whale as one example. The values themselves are often calculated from the energy consumption rate that is roughly equal to the energy production rate, or in other cases from the oxygen consumption.

A famous illustration representing this relationship is shown in Figure 1.

relationship between basal metabolic rate body mass and surface area

The difference between Over the years, several models have been put forward to rationalize why the scaling is different from that expected based on surface area. Most prominent are models that discuss the rate of energy supply in hierarchical networks, such as blood vessels in our body, which supply the oxygen required for energy production in respiration.

relationship between basal metabolic rate body mass and surface area

The respiratory quotient for protein metabolism can be demonstrated by the chemical equation for oxidation of albumin: This process could severely degrade the protein structures needed to maintain survival such as contractile properties of proteins in the heart, cellular mitochondria, myoglobin storage, and metabolic enzymes within muscles.

The oxidative system aerobic is the primary source of ATP supplied to the body at rest and during low intensity activities and uses primarily carbohydrates and fats as substrates.

Protein is not normally metabolized significantly, except during long term starvation and long bouts of exercise greater than 90 minutes. Following the onset of activity, as the intensity of the exercise increases, there is a shift in substrate preference from fats to carbohydrates. Both studies find that aerobic fitness levels do not improve the predictive power of fat free mass for resting metabolic rate.

However recent research from the Journal of Applied Physiology, published in Sep.

relationship between basal metabolic rate body mass and surface area

PMC, compared Resistance Training and Aerobic training on body mass and fat mass in overweight adults: When you consider time commitments against health benefits, AT is the optimal mode of exercise for reducing fat mass and body mass as a primary consideration, RT is good as a secondary factor when aging and lean mass are a concern. RT causes injuries at a much higher rate than AT. RT if time is available is also helpful in post exercise metabolism, but it is an adjunctive factor because the body needs to heal sufficiently between RT episodes, whereas with AET, the body can accept this every day.

Metabolic rate

Anaerobic exercisesuch as weight liftingbuilds additional muscle mass. Muscle contributes to the fat-free mass of an individual and therefore effective results from anaerobic exercise will increase BMR. Various studies [26] [27] suggest that the resting metabolic rate of trained muscle is around 55kJ per kilogram, per day. Heartbeat hypothesis InRaymond Pearl proposed that longevity varies inversely with basal metabolic rate the "rate of living hypothesis".

Support for this hypothesis comes from the fact that mammals with larger body size have longer maximum life spans large animals do have higher total metabolic rates, but the metabolic rate at the cellular level is much lower, and the breathing rate and heartbeat are slower in larger animals and the fact that the longevity of fruit flies varies inversely with ambient temperature.

relationship between basal metabolic rate body mass and surface area

Calorie restriction and reduced thyroid hormone levels, both of which decrease the metabolic rate, have been associated with higher longevity in animals.

Animals also vary in the degree of coupling between oxidative phosphorylation and ATP productionthe amount of saturated fat in mitochondrial membranesthe amount of DNA repairand many other factors that affect maximum life span.

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» How does metabolic rate scale with size?

June Learn how and when to remove this template message In allometric scalingmaximum potential life span MPLS is directly related to metabolic rate MRwhere MR is the recharge rate of a biomass made up of covalent bonds. That biomass W is subjected to deterioration over time from thermodynamic, entropic pressure. Metabolism is essentially understood as redox coupling, and has nothing to do with thermogenesis. Metabolic efficiency ME is then expressed as the efficiency of this coupling, a ratio of amperes [ clarification needed ] captured and used by biomass, to the amperes available for that purpose.

MR is measured in watts, W is measured in grams. All of the cells of an organism fit into this range, i.

relationship between basal metabolic rate body mass and surface area

Weight training can have a longer impact on metabolism than aerobic trainingbut there are no known mathematical formulas that can exactly predict the length and duration of a raised metabolism from trophic changes with anabolic neuromuscular training. A decrease in food intake will typically lower the metabolic rate as the body tries to conserve energy. Some research has focused on developing antiobesity drugs to raise the metabolic rate, such as drugs to stimulate thermogenesis in skeletal muscle.

  • Metabolic rate
  • Basal metabolic rate

The metabolic rate may be elevated in stressillnessand diabetes.