Comparison of oxygen uptake during and after the execution of resistance exercises and exercises performed on ergometers, matched for intensity.

The aim of this study was to compare the values of oxygen uptake (VO2) during and after strength training exercises (STe) and ergometer exercises (Ee), matched for intensity and exercise time. Eight men (24 ± 2.33 years) performed upper and lower body cycling Ee at the individual's ventilatory threshold (VE/VCO2).

Combustion, respiration and intermittent exercise: a theoretical perspective on oxygen uptake and energy expenditure.

While no doubt thought about for thousands of years, it was Antoine Lavoisier in the late 18th century who is largely credited with the first "modern" investigations of biological energy exchanges. From Lavoisier's work with combustion and respiration a scientific trend emerges that extends to the present day: the world gains a credible working hypothesis but validity goes missing, often for some time, until later confirmed using proper measures. This theme is applied to glucose/glycogen metabolism where energy exchanges are depicted as conversion from one form to another and, transfer from one place to another made by both the anaerobic and aerobic biochemical pathways within working skeletal muscle, and the hypothetical quantification of these components as part of an oxygen (O2) uptake measurement.

Estimating the energy costs of intermittent exercise.

To date, steady state models represent the only acceptable methodology for the estimation of exercise energy costs. Conversely, comparisons made between continuous and intermittent exercise generally reveal major physiological discrepancies, leading to speculation as to why steady state energy expenditure models should be applied to intermittent exercise. Under intermittent conditions, skeletal muscle invokes varying aerobic and anaerobic metabolic responses, each with the potential to make significant contributions to overall energy costs.

Glucose and fat oxidation: bomb calorimeter be damned.

For both respiration and combustion, the energy loss difference between glucose and fat oxidation often is referenced to the efficiency of the fuel. Yet, the addition of anaerobic metabolism with ATP resynthesis to complete respiratory glucose oxidation further contributes to energy loss in the form of entropy changes that are not measured or quantified by calorimetry; combustion and respiratory fat/lactate oxidation lack this anaerobic component. Indeed, the presence or absence of an anaerobic energy expenditure component needs to be applied to the estimation of energy costs in regard to glucose, lactate, and fuel oxidation, especially when the measurement of oxygen uptake alone may incorrectly define energy expenditure.

The effect of time-under-tension and weight lifting cadence on aerobic, anaerobic, and recovery energy expenditures: 3 submaximal sets.

We examined the aerobic and anaerobic energy expenditures of weight lifting (bench press); submaximal work was kept constant among protocols. Ten male subjects (age, 23.2 ± 3.

Energy expenditure characteristics of weight lifting: 2 sets to fatigue.

We investigated the work performed and energy expenditure characteristics within and among 2 sets of the bench press at 70%, 80%, and 90% of 1 repetition maximum (1RM). For both sets fatigue was the end point. We asked: do multiple sets affect subsequent work output along with aerobic, anaerobic, and excess postexercise oxygen consumption (EPOC) contributions? Ten males participated.

Quantifying the immediate recovery energy expenditure of resistance training.

As opposed to steady state aerobic-type exercise involving long duration, continuous, rhythmic, large muscle group activities that consume large volumes of oxygen, a resistance training set is brief, intermittent, uses multiple and isolated muscles, and is considered anaerobic in description. Because differences are evident between aerobic- and anaerobic-type exercise, it is proposed that the methods used for estimating resistance training energy expenditure should be different as compared with walking, jogging, cycling, etc. After a single set of weight lifting, for example, oxygen uptake is greater in the recovery from lifting as opposed to during the actual exercise; likewise, the anaerobic energy expenditure contribution to lifting may exceed exercise oxygen uptake.

Aerobic, anaerobic, and excess postexercise oxygen consumption energy expenditure of muscular endurance and strength: 1-set of bench press to muscular fatigue.

We use a new approach to the estimation of energy expenditure for resistance training involving nonsteady state measures of work (weight × displacement), exercise O2 uptake, blood lactate, and recovery O2 uptake; all lifts were performed to muscular failure. Our intent was to estimate and compare absolute and relative aerobic and anaerobic exercise energy expenditure and recovery energy expenditure. Single-set bench press lifts of ∼ 37, ∼ 46, and ∼ 56% (muscular endurance-type exercise) along with 70, 80, and 90% (strength-type exercise) of a 1 repetition maximum were performed.

Energy expenditure before, during, and after the bench press.

We examined the reliability and validity of non-steady-state aerobic and anaerobic estimations of energy expenditure during and after bouts of the bench press exercise. A Smith machine, not free weights, was used. On different days, 8 subjects (28.

Onset of the Thermic Effect of Feeding (TEF): a randomized cross-over trial.

Background: The purpose of this investigation was to identify the onset of the thermic effect of feeding (TEF) after ingestion of a high carbohydrate (CHO) and a high protein (PRO) 1255 kJ (300 kcal) drink.

Methods: Resting metabolic rate (RMR) and TEF were measured over 30-minute periods via indirect calorimetry using a ventilated hood technique. Eighteen subjects (7 men and 11 women) completed two randomized, double-blind trials.

Contribution of blood lactate to the energy expenditure of weight training.

Bioenergetic interpretations of energy transfer specify that rapid anaerobic, substrate-level adenosine triphosphate (ATP) turnover with lactate production is not appropriately represented by an oxygen uptake measurement. Two types of weight training, 60% of 1 repetition maximum (1RM) with repetitions to exhaustion and 80% of 1RM with limited repetitions, were compared to determine if blood lactate measurements, as an estimate of rapid substrate-level ATP turnover, provide a significant contribution to the interpretation of total energy expenditure as compared with oxygen uptake methods alone. The measurement of total energy expenditure consisted of blood lactate, exercise oxygen uptake, and a modified excess postexercise oxygen consumption (EPOC); oxygen uptake-only measurements consisted of exercise oxygen uptake and EPOC.

Estimating energy expenditure for brief bouts of exercise with acute recovery.

Four indirect estimations of energy expenditure were examined, (i) O(2) debt, (ii) O(2) deficit, (iii) blood lactate concentration, and (iv) excess CO(2) production during and after 6 exercise durations (2, 4, 10, 15, 30, and 75 s) performed at 3 different intensities (50%, 100%, and 200% of VO(2) max). Analysis of variance (ANOVA) was used to determine if significant differences existed among these 4 estimations of anaerobic energy expenditure and among 4 estimations of total energy expenditure (that included exercise O(2) uptake and excess post-exercise oxygen consumption, or EPOC, measurements). The data indicate that estimations of anaerobic energy expenditure often differed for brief (2, 4, and 10 s) bouts of exercise, but this did not extend to total energy expenditure.

Differences in oxygen uptake but equivalent energy expenditure between a brief bout of cycling and running.

Background: We examined aerobic and anaerobic exercise energy expenditure and excess post-exercise oxygen consumption (EPOC) between a 250 Watt, 1-minute bout of cycling and uphill treadmill running.

Methods: Fourteen active to well-trained subjects volunteered for the investigation (VO2 max: 57.0 +/- 12.

Contribution of anaerobic energy expenditure to whole body thermogenesis.

Heat production serves as the standard measurement for the determination of energy expenditure and efficiency in animals. Estimations of metabolic heat production have traditionally focused on gas exchange (oxygen uptake and carbon dioxide production) although direct heat measurements may include an anaerobic component particularly when carbohydrate is oxidized. Stoichiometric interpretations of the ratio of carbon dioxide production to oxygen uptake suggest that both anaerobic and aerobic heat production and, by inference, all energy expenditure--can be accounted for with a measurement of oxygen uptake as 21.

Direct and indirect calorimetry of lactate oxidation: implications for whole-body energy expenditure.

Whole-body energy expenditure for heavy/severe exercise is currently accounted for by either: (1) anaerobic and oxygen uptake measures during exercise where recovery energy expenditure is omitted; or (2) oxygen uptake during, and an EPOC (excess post-exercise oxygen consumption), measure following exercise where substrate level phosphorylation during exercise is considered part of EPOC. Simultaneous direct/indirect calorimetry enabled us to determine if a thermodynamic reversal (i.e.

Unloading-induced remodeling in the normal and hypertrophic left ventricle.

To date, no study has assessed the degree of similarity between left ventricular (LV) reverse remodeling and atrophic remodeling. Stable LV hypertrophy was induced by creation of an arteriovenous fistula (AVF) in Lewis rats (32 days). LV unloading was induced by heterotopic transplantation of normal (NL-HT) and/or hypertrophic (AVF-HT) hearts (7 days).