Pediatric Exercise Testing: Value and Implications of Peak Oxygen Uptake.

Peak oxygen uptake (peak V ˙ O 2 ) measured by clinical exercise testing is the benchmark for aerobic fitness. Aerobic fitness, estimated from maximal treadmill exercise, is a predictor of mortality in adults. Peak V ˙ O 2 was shown to predict longevity in patients aged 7-35 years with cystic fibrosis over 25 years ago.

The clinical translation gap in child health exercise research: a call for disruptive innovation.

In children, levels of play, physical activity, and fitness are key indicators of health and disease and closely tied to optimal growth and development. Cardiopulmonary exercise testing (CPET) provides clinicians with biomarkers of disease and effectiveness of therapy, and researchers with novel insights into fundamental biological mechanisms reflecting an integrated physiological response that is hidden when the child is at rest. Yet the growth of clinical trials utilizing CPET in pediatrics remains stunted despite the current emphasis on preventative medicine and the growing recognition that therapies used in children should be clinically tested in children.

Simulated obesity-related changes in lung volume increases airway responsiveness in lean, nonasthmatic subjects.

Study Objective: To determine if obesity-related changes in lung volume might contribute to airway reactivity, we investigated the effects of simulated mild obesity-related lung volume reductions on airway responsiveness in lean, nonasthmatic subjects.

Participants And Methods: We simulated the lung volume reductions of class 1 obesity in eight lean, nonasthmatic subjects by externally mass loading the chest wall and abdomen, and shifting blood volume into the lung with lower limb compression (LLC). Airway responsiveness was assessed by measuring FEV(1) before and after methacholine challenge tests (1, 2.

Development of an unsupported arm exercise test in patients with chronic obstructive pulmonary disease.

Background: Unsupported arm exercise tests have been used to evaluate the effects of pulmonary rehabilitation in patients with chronic obstructive pulmonary disease (COPD), but the reliability and validity of these tests are not established.

Objective: We evaluated the test-retest reliability and validity of a 6-minute pegboard and ring test (PBRT) in 27 outpatients with COPD and 30 age-matched controls.

Methods: We evaluated a 6-minute PBRT, subject demographics, pulmonary function and disease-specific quality of life questionnaire, and the Pulmonary Functional Status Dyspnea Questionnaire-Modified version in 27 patients with COPD.

Arm work interferes with normal ventilation.

Arm work, by limiting movement of the chest wall and use of the respiratory muscles, may alter breathing pattern and gas exchange sufficiently to interfere with the ability to perform certain tasks. To determine the effects of arm work on breathing pattern during a well-controlled work task, depth of breathing, breathing frequency and end-expiratory lung volume (EELV) were measured at rest and during cycling exercise using an arm and a leg ergometer. Six subjects performed arm work at light, moderate and heavy intensities (30%, 60% and 90% of maximum arm work capacity respectively) and leg work at three intensities where ventilation was matched for that achieved during the arm work.

Physiologic evidence for the efficacy of positive expiratory pressure as an airway clearance technique in patients with cystic fibrosis.

Background And Purpose: Individuals with cystic fibrosis (CF) have large amounts of infected mucus in their lungs, which causes irreversible lung tissue damage. Although patient-administered positive expiratory pressure (PEP) breathing has been promoted as an effective therapeutic modality for removing mucus and improving ventilation distribution in these patients, the effects of PEP on ventilation distribution and gas mixing have not been documented. Therefore, this preliminary investigation described responses in distribution of ventilation and gas mixing to PEP breathing for patients with moderate to severe CF lung disease.

Ventilatory response to exercise in simulated obesity by chest loading.

Introduction & Purpose: Obesity-related increases of weight on the chest wall are known to decrease lung volume and chest wall compliance, but the effect of this mass loading, independent of other obesity-related complications on the ventilatory response to exercise is unknown. The purpose of this study was to investigate the effect of chest mass loading on the ventilatory response to exercise.

Methods: External chest loading (CL) was used to simulate the effect of moderate obesity (BMI = 32 kg x m).

Neandertal cold adaptation: physiological and energetic factors.

European Neandertals employed a complex set of physiological cold defenses, homologous to those seen in contemporary humans and nonhuman primates. While Neandertal morphological patterns, such as foreshortened extremities and low relative surface-area, may have explained some of the variance in cold resistance, it is suggested the adaptive package was strongly dependent on a rich array of physiological defenses. A summary of the environmental cold conditions in which the Neandertals lived is presented, and a comparative ethnographic model from Tierra del Fuego is used.

Exercise and Cystic Fibrosis: A Review.

Cystic fibrosis (CF) results in chronic obstructive pulmonary disease with progressive increases in areas of the lung with poor gas exchange (dead space). The pulmonary response to exercise is characterized by a higher than expected minute ventilation (V̇). In some patients the elevated V̇is inadequate to overcome the large dead space, resulting in decreases in arterial oxygen and/or increases in arterial carbon dioxide levels during exercise.