Airway obstruction during exercise in asthma.

Airway obstruction (AO) in exercise-induced asthma (EIA) is considered a postexercise phenomenon. However, many with EIA complain of respiratory distress during exercise. We evaluated AO in six asthmatic subjects during a short (SX = 6 min) and a long (LX = 20 min) exercise session.

Longitudinal effects of aging on lung function at rest and exercise in healthy active fit elderly adults.

We retested 18 healthy, active, and highly fit [maximal O2 consumption (VO2max) 201 +/- 12% of predicted] older adults over a 6-yr period (mean age 67-->73 yr) to determine the longitudinal effects of aging on lung function at rest and during exercise. In the 6-yr period, total lung capacity (TLC), functional residual capacity, and diffusion capacity did not change; vital capacity, forced expiratory volume in 1 s, and maximal volitional flow rates decreased; and residual volume and closing capacity/TLC increased 11-13%, all of which were greater than predicted from cross-sectional data. At maximum exercise over the 6-yr period, VO2max fell 11.

Static lung load and posture effects on pulmonary mechanics and comfort in underwater exercise.

Static lung load (SLL), or transrespiratory pressure gradient, imposed by underwater breathing apparatus can affect breathing comfort and mechanics, especially during exertion. We examined the effects of body position and SLL on two factors known to affect or limit exertion: a) tidal flow-volume limitation, i.e.

Mechanical constraints on exercise hyperpnea in a fit aging population.

We studied 12 physically fit (VO2 max = 44 ml.kg-1.min-1) older subjects (age = 63 to 77 yr) who showed the usual age-related declines in lung function (i.

Flow limitation and regulation of functional residual capacity during exercise in a physically active aging population.

In 29 older (69 +/- 1 yr), physically active subjects (VO2max = 44 +/- 2 ml.kg-1.min-1), we determined the effect of an age-related decline in elastic lung recoil (i.

Differences in frequency of finger tremor in otherwise asymptomatic mercury workers.

Tremor was measured from the index finger during low force, position holding in 18 control subjects and 18 battery workers with low level exposure to mercury. All workers were asymptomatic on clinical neurological examination. No differences were found in average tremor amplitudes between the groups, but statistically significant abnormalities in tremor frequency distribution existed.

Behavioral effects of increased CO2 load in divers.

The behavioral effects of elevated PACO2 were examined to clarify risks due to CO2 retention in diving. In two separate laboratory studies, experienced divers breathed 6% CO2 mixtures under normobaric conditions. Normoxic study: Subjects (n = 8) first breathed air (control); then 6% CO2, 21% O2, balance N2 (exposure); and then air again (postexposure).

Assessment of a cold air breathing aid.

During nasal breathing, heat and humidity are exchanged over a 160 cm(2) area of mucous membrane. This capacity is not sufficient for airway comfort during cold air breathing. Similarly, airway discomfort and constriction may be experienced during exercise-induced mouth breathing in marginally cold temperatures.

The effects of post-exercise glucose and alanine ingestion on plasma carnitine and ketosis in humans.

1. Several studies have hypothesized that alanine decreases plasma ketone body levels by increasing availability of oxaloacetate, thus allowing acetyl groups to enter the tricarboxylic acid cycle and releasing co-enzyme A (CoA). 2.

Physiologic and metabolic response to progressive and prolonged exercise in amyotrophic lateral sclerosis.

Physical work capacity in 35 ALS patients and 6 untrained controls was evaluated during progressive bicycle ergometry. In the ALS patients, maximum oxygen consumption (VO2max) and work capacity (Wmax) drop in relation to the decrease in ALS functional score. However, the oxygen cost (ml O2/kpm) of submaximal exercise was significantly increased.

Role of muscular exercise in amyotrophic lateral sclerosis.

The general, systemic, and specific neuromuscular adaptation to physical exercise and training in healthy individuals is reviewed with application to individuals with neuromuscular disease in general and ALS in particular. A pilot study utilizing patients with ALS suggests the cardiopulmonary response to acute exercise is similar to normal individuals. However, a case study of a training response suggests the success of neuromuscular adaptation will be dependent upon the degree of motor neuron involvement.

Carnitine metabolism during prolonged exercise and recovery in humans.

Lennon et al. (J. Appl.

Epidemiologic study of clinical and physiologic parameters in grain handlers of northern United States.

To study the effects of grain dust exposure, we compared respiratory parameters between 310 grain handlers and 237 city workers of comparable age, height, weight, and smoking habits. Both populations resided and worked in the same geographic area of the United States. Information was obtained by questionnaire, interview, and examination.

Physical work capacity in adolescent patients with mild idiopathic scoliosis.

The purpose of this study was to investigate the physical work capacity of adolescent patients with mild idiopathic scoliosis (less than 60 degrees). Fourteen subjects, who were being treated with a Milwaukee brace, were given a progressive exercise stress test. Ventilatory volume, frequency of breathing, end-tidal PCO2, heart rate, and blood pressure were continuously monitored and oxygen consumption (VO2) was computed for each work load.

Acute effects of grain dust exposure during a work shift.

We studied 248 grain handlers and 192 city services workers (control subjects) before and after an 8-h work shift and measured total dust levels using personal samplers. We found that grain workers exposed to a mean total dust level of 3.3 +/- 7.

Chest wall and abdominal motion during exercise in patients with chronic obstructive pulmonary disease.

The study was undertaken to evaluate the role of coordination between the chest wall and abdomen during exercise in patients with chronic obstructive pulmonary disease (COPD). There were 40 patients with COPD and 6 control subjects with normal lung function who underwent a progressive exercise stress test on a treadmill ergometer. The normal subjects exhibited symmetrical motion between the chest wall and abdomen.

Exercise training in patients with COPD.

Exercise is a useful therapeutic intervention for many COPD patients. The progressive stress test is the single most important means of clinical evaluation, although a thorough physical examination and preexercise ECG are also mandatory. The exercise program is prescribed according to duration of exercise and the maximal load reached by the patient during testing.

Determinants and consequences of ventilatory responses to competitive endurance running.

Pulmonary ventilation and pattern, arterial blood gases, and [H+] were studied in 15 highly trained runners [maximum O2 consumption (VO2 max) 53--82 ml . kg-1 . min-1] during road racing (24 km, n = 5) and 60--70 min of treadmill running (70--75% VO2 max, n = 13).

Physical activity and calcium modalities for bone mineral increase in aged women.

This study tested the hypothesis that physical activity and/or supplemental calcium (0.75 g/day) and vitamin D (400 IU) would effectively slow bone loss, and /or increase bone mineral content (BMC) in aged females (X = 81) over three years. In vivo BMC and width of the radius was determined by photon absorptiometry at two sites.

Respiratory abnormalities among grain handlers: a clinical, physiologic, and immunologic study.

A survey of 300 grain elevator workers revealed that 77 per cent complained of eye symptoms; 64 per cent, of nasal symptoms; and 88 per cent, of one or more respiratory symptoms on exposure to airborne grain dust. Symptoms on exposure were independent of age and length of employment. Cough and wheezing on exposure were more common among smokers than nonsmokers (P less than 0.