Energy expenditure of heavy to severe exercise and recovery.

A method of indirect calorimetry is proposed that attempts to better quantify the energy expenditure associated with heavy/severe exercise and the recovery from that exertion. To accomplish this objective, the energy expenditure associated with rapid anaerobic glycolysis is separated from that of mitochondrial respiration both during and after heavy/severe exercise. This model contrasts with those hypotheses that employ oxygen uptake as the sole measure of energy expenditure (e.g. the oxygen debt) or that utilizing a measure of anaerobic energy expenditure while ignoring the recovery energy expenditure. Anaerobic metabolism and its energy promoting effect on oxidative recovery must be independently acknowledged regardless of the eventual fate of lactate.

Issues in quality of life assessment during cancer therapy.

Current treatments for cancer do not differentiate between malignant and normal cells; this limitation results in the adverse effects associated with radiotherapy and chemotherapy. Adverse effects of treatment severely impact the cancer patient's quality of life. Quality of life assessment can help the clinician gauge the efficacy of interventions that reduce the adverse effects of radiotherapy and chemotherapy. Quality of life is an increasingly important outcome measure in the evaluation of cancer treatments, and a variety of tools have been developed for evaluating changes in quality of life. This report reviews several of these measurement tools, focusing primarily on those used in lung cancer trials.

Aerobic and anaerobic energy expenditure during exhaustive ramp exercise.

Ramp tests are often manipulated so that oxygen uptake is able to interpret energy expenditure in its entirety. We hypothesized that oxygen deficits during ramp exercise to exhaustion would be significant, providing a more complete description of the types of energy expenditure available for this mode of testing. Oxygen deficits were obtained during a slow ramp (681 +/- 71 s) and a fast ramp (275 +/- 33 s) to exhaustion. Twelve healthy men (age 35 +/- 3 yrs; VO2max 51 +/- 10 ml x kg(-1) x min(-1)) performed several 10 min submaximal bike rides (at or below ventilatory threshold) to determine work rate -O2 uptake demands. Estimated O2 demands were compared to measured O2 uptake during each ramp test, the difference representing an oxygen deficit. Work levels were controlled and measurements collected with a commercially available electrically braked bike ergometer and metabolic testing system (MedGraphics, Minn., MN). Data were collected and averaged in 30 s time periods, power in watts (W), energy expenditure in cumulative O2 (L). Using a paired t-test, cumulative O2 uptakes were significantly lower (p = 0.0001) when measured O2 uptakes (26.0 L +/- 4.5 for slow ramp; 10.8 L +/- 2.8 for fast ramp) were compared to estimated O2 demands (29.0 L +/- 3.7 for slow ramp; 14.1 L +/- 3.5 for fast ramp). Anaerobic energy expenditures (oxygen deficits) represented 10.8% and 23.4% of total energy expenditure for slow ramps and fast ramps, respectively. Comparisons of the slopes for each test condition revealed significant differences (steady state > slow ramp > fast ramp; p = 0.0001,ANOVA). We conclude that the oxygen deficit during ramp testing represents a significant part of total energy expenditure.

Re-interpreting anaerobic metabolism: an argument for the application of both anaerobic glycolysis and excess post-exercise oxygen comsumption (EPOC) as independent sources of energy expenditure.

Due to current technical difficulties and changing cellular conditions, the measurement of anaerobic and recovery energy expenditure remains elusive. During rest and low-intensity steady-state exercise, indirect calorimetric measurements successfully represent energy expenditure. The same steady-state O2 uptake methods are often used to describe the O2 deficit and excess post-oxygen consumption (EPOC): 1 l O2 = 5 kcal = 20.9 kJ. However, an O2 deficit plus exercise O2 uptake measurement ignores energy expenditure during recovery, and an exercise O2 uptake plus EPOC measurement misrepresents anaerobic energy expenditure. An alternative solution has not yet been proposed. Anaerobic glycolysis and mitochondrial respiration are construed here as a symbiotic union of metabolic pathways, each contributing independently to energy expenditure and heat production. Care must be taken when using O2 uptake alone to quantify energy expenditure because various high-intensity exercise models reveal that O2 uptake can lag behind estimated energy demands or exceed them. The independent bioenergetics behind anaerobic glycolysis and mitochondrial respiration can acknowledge these discrepancies. Anaerobic glycolysis is an additive component to an exercise O2 uptake measurement. Moreover, it is the assumptions behind steady-state O2 uptake that do not permit proper interpretation of energy expenditure during EPOC; 1 l O2 not = 20.9 kJ. Using both the O2 deficit and a modified EPOC for interpretation, rather than one or the other, leads to a better method of quantifying energy expenditure for higher intensity exercise and recovery.

Home care: what is it?

The oft quoted phrase, "There's no place like home," has no greater meaning than when long-term care decisions are being made. In the midst of ongoing late life changes, one's home is often the only anchor. Through carefully selected home care and nursing and care management services, living at home remains a viable option for older adults and their families. Physicians can serve as a vital link between older adults and the home care system by educating the patient where services can be obtained. Physician input into referral and collaboration with other care managers can help determine the best approach to home care.

Interpreting energy expenditure for anaerobic exercise and recovery: an anaerobic hypothesis.

Energy expenditure during and after exercise is composed of aerobic and anaerobic bioenergetics and the energy demands of aerobic recovery. Current attempts to measure energy expenditure include an exercise oxygen uptake + oxygen debt (EPOC) measurement or, an oxygen deficit + exercise oxygen uptake measurement. This investigation illustrates how oxygen debt and oxygen deficit interpretation can effect a total energy expenditure measurement. It was hypothesized that the total energy expenditure for several intermittent bouts of exercise and recovery would be greater than for one bout of continuous exercise and recovery when equivalent work was compared. Exercise was performed under low-intensity and high-intensity conditions. Both oxygen debt and oxygen deficit methodology resulted in similar energy expenditure measurements for both intermittent and continuous exercise. This implies little to no recovery energy demand or considerable methodology errors. Differences in total energy expenditure were found when the oxygen deficit and parts of the oxygen debt (EPOC) were considered separate and independent (p < 0.05). These differences can be accounted for when the data are interpreted utilizing thermodynamic (2nd law) and engineering (in-series efficiency) concepts rather than the heat equivalent of carbohydrate oxidation (20.9 kJ equals one liter of O2). It is suggested that while oxygen uptake provides an excellent representation of aerobic metabolism during exercise and recovery, oxygen uptake may be an inadequate measure of the energetics of lactate production (fermentation). In application, energy expenditure differences appear realistic only for high-intensity, intermittent exercise rather than lower intensity exercise.

A model emerges for the community-based nurse care management of older adults.

Changes in the demographics of older adults and the structure and financing of the health care delivery system have created a need to develop alternative models of care delivery for the elderly. The nurse care management model is a potentially cost-effective solution for provision of comprehensive care to this population. By providing timely health promotion and illness prevention education, as well as coordinating community resources, nurses can reduce the health care costs of this growing segment of the population. Funding this model, however, remains a challenge as such services are not directly reimbursed by third-party payers.

Radiation Therapy Oncology Group quality of life assessment: design, analysis, and data management issues.

The Radiation Therapy Oncology Group (RTOG) has embarked on seven phase II or phase III multicentre clinical trials involving a quality of life component. Each quality of life trial used questionnaires or examinations that have been tested for reliability and validity by independent investigators. Each trial includes questionnaires that examine the patient's physical, functional, social, and emotional status, and that measure a specific quality of life issue pertinent to the patient's diagnosis or treatment. Two trial designs have been implemented for studies with quality of life endpoints. One design involves companion trials to the primary treatment study pertaining solely to the quality of life endpoint. The second design integrates the quality of life component into the primary trial design. The RTOG has found a need for education of individuals and institutions expected to administer and obtain the quality of life data. Once the data have been collected several methods for the analysis of the quality of life data are available. However, there is no one best method for analysing quality of life data, thus more than one method should be used in order to provide insight into the data.