The effect of habitual smoking on measured and predicted VO2(max).

Background: Nonexercise models were developed to predict maximal oxygen consumption (VO2(max)). While these models are accurate, they don't consider smoking, which negatively impacts measured VO2(max). The purpose of this study was to examine the effects of smoking on both measured and predicted VO2(max).

Temporal and postural variation of 12-lead high-frequency QRS electrocardiographic signals in asymptomatic individuals.

Because changes in the 12-lead high-frequency QRS electrocardiogram (HF QRS ECG) more sensitively identify myocardial ischemia than do changes in the ST segments of the conventional ECG, it is important that changes in HF QRS signals that are merely physiological be distinguishable from those that are potentially pathological. We therefore studied the temporal variation of HF QRS measures such as root mean square (RMS) voltage and the presence vs absence of reduced amplitude zones (RAZs) in 107 asymptomatic individuals in the supine position during a brief period of ECG monitoring. In addition, to ascertain the effects of posture on the 12-lead HF QRS ECG, we collected additional seated data from 25 of these individuals and estimated the fifth and 95th percentile of the percent relative change between the supine and seated measurements.

Nonexercise models for estimating VO2max with waist girth, percent fat, or BMI.

Unlabelled: Previously published nonexercise models using either percent fat or body mass index (BMI) as body composition measures provided valid estimates of VO2max.

Purpose: This study was conducted to investigate the use of waist girth (WG) as a body composition surrogate in the nonexercise models and to compare the accuracy of nonexercise models that include WG, %fat, or BMI.

Methods: A total of 2417 men and 384 women were measured for VO2max by indirect calorimetry (RER > 1.