Bryant Stamford

Smoking and smoking cessation-The relationship between cardiovascular disease and lipoprotein metabolism : A review

Cigarette smoking is generally accepted as the most preventable cause of death in the United States today. Individuals who smoke experience a wide range of physiologic side effects that increase the risk of cardiovascular disease (CVD), including insulin resistance, elevated catecholamine levels which contribute to an elevated heart rate and blood pressure, and hypercholesterolemia. The link between hypercholesterolemia and cardiovascular disease has been extensively researched and is undeniable. What is more, this link is strengthened in smokers as cigarette smoking is known to increase total cholesterol (TC), triglycerides (TG), and low-density lipoprotein (LDL), while acting to decrease the cardio-protective high-density lipoprotein (HDL). Alterations in the enzymes that control lipid transport may be a key underlying mechanism contributing to these health destroying effects. This review examines the current literature related to: (1) smoking, lipoproteins, and lipid-related enzymes; (2) the impact of nicotine, carbon monoxide and free radicals on physiologic parameters related to health; and (3) metabolic issues involving smoking cessation and nicotine replacement therapy.

Validity and Reliability of Subjective Ratings of Perceived Exertion During Work.

The purpose of the present investigation was to determine the reliability of the Borg (RPE) Scale under a variety of experimental conditions. Fourteen sedentary female subjects performed six repeated work tasks (12 in all) distributed over four experimental testing sessions and presented in a randomized order. Work tasks involved treadmill walking and jogging, cycling, and stool stepping. Work loads were presented in progressive (step-wise), oscillating, or single load submaximal intensities. During work, heart rate (HR) was recorded at regular intervals and ratings of perceived exertion (RPE) were elicited either at regular intervals (interval) or only during the final minute of work (terminal). RPE responses were found to be highly reproducible whether interval or terminal. High correlations were also found between interval and terminal RPE responses. RPE demonstrated a strong relationship with HR and work intensity. It was concluded that category ratings of perceived exertion according to the Borg (RPE) Scale offer a sensitive and reliable measure of stress encountered during work.

Exercise Recovery, Lactate Removal, and Subsequent High Intensity Exercise Performance.

Abstract In order to examine the effects of different recoveries from high intensity short duration exercise on lactate removal and subsequent performance, 11 subjects completed 8 experimental sessions. Each subject completed an initial all-out pedaling task against 5.5 kg resistance (Monark bicycle ergometer) for 1 min followed by a randomly assigned recovery pattern and a repeat of the all-out exercise task. The main effects examined were active (1.0 kg, 60 rpm) vs passive recovery, inhalation of inhalation of oxygen vs room air during recovery, and 10- vs-20-min duration of recovery. Pedal revolutions were analyzed on a 6- by 6-sec and on a cumulative basis. Blood lactate concentrations were determined during rest, the 3rd–4th, 9th–10th, and 19th–20th min of recovery. Results revealed significant main effects for active vs passive recovery and for 10- vs 20-min recovery, with active and 20-min recovery resulting in significantly higher postrecovery pedal revolutions (p < .001) and enhanced rates of lac...

Cigarette smoking, physical activity, and alcohol consumption: Relationship to blood lipids and lipoproteins in premenopausal females

A total of 164 premenopausal female subjects were randomly selected for evaluation from a much larger pool of volunteers. The relationships between blood lipid and lipoprotein levels as dependent variables and cigarette smoking, physical activity, and alcohol consumption were determined from partial regression coefficients. A lower HDL-C level (10.1 mg/dL) was seen in smokers v nonsmokers. For each ounce of alcohol consumed, HDL-C level was higher by 2.8 mg/dL, and greater physical activity was associated with a higher HDL-C level of 8.6 mg/dL. An analysis of covariance with covariance adjustments for age and body fat revealed that smokers who regularly exercise or consume alcohol had significantly lower HDL-C levels than nonsmokers with similar habits. Subjects who both exercise and consume alcohol demonstrated higher HDL-C levels than those who indulge in one or the other separately. Results suggest that cigarette smoking may attenuate the effects of chronic exercise or alcohol consumption, or of both, to raise HDL-C levels. Also, chronic exercise and alcohol consumption may exert an additive effect, raising HDL-C level.

Cigarette smoking, exercise and high density lipoprotein cholesterol

Cigarette smoking is associated with depressed levels of HDL-C, whereas exercise is associated with elevated levels of HDL-C. The purpose was to determine effects of smoking and exercise on blood lipids and lipoproteins in middle-aged males. It was hypothesized that smoking may attenuate the effects of exercise to elevate HDL-C. A total of 269 males (70 smokers) met all criteria for inclusion in the study population. Age, height, weight, body fatness via hydrostatic weighing, daily caloric consumption and alcohol intake, and smoking habits and history were determined. Interviews concerning physical activity patterns were conducted and cardiovascular responses to treadmill exercise were determined. Subjects were grouped as sedentary (low activity), participants in vigorous recreational activities (moderate activity) and joggers/runners (high activity). Analysis of covariance with adjustments for factors which may affect blood lipids and lipoproteins was employed. Smokers demonstrated lower HDL-C and higher total cholesterol levels than nonsmokers. High activity subjects demonstrated significantly higher HDL-C levels than the low and moderate groups which did not differ. High activity smokers did not differ from low activity nonsmokers with respect to HDL-C. This supports the proposed hypothesis. Nonsmokers were higher in weight and body fatness than smokers even though smokers consumed 288 more calories per day on the average. This suggests that smoking may account for a significant number of calories through altered metabolism or some other means.

Effects of Daily Physical Exercise on the Psychiatric State of Institutionalized Geriatric Mental Patients

Abstract Nine male geriatric mental patients exercised daily, Monday through Friday for a total of 12 weeks. Exercise was in the form of walking on a motor-driven treadmill at workloads which elicited 70% of the age adjusted, predicted maximal heart rate. Eight patients served as controls and received similar social stimulation as did the experimental patients. All patients were physiologically evaluated on treadmill and bicycle ergometer stress tests administered before and immediately following the 12 wk. training period. Psychiatric evaluation was in the form of a series of four psychological tests also administered pre- and posttraining. Results of the posttraining evaluation indicate a physiological training effect experienced by experimental patients as evidenced by significantly decreased heart rate and systolic blood pressure responses to treadmill and bicycle ergometer constant workload tests. Accompanying the physiological training effect was a significant change on two of the four psychological...

Smoking multiple high- versus low-nicotine cigarettes: Impact on resting energy expenditure

The thermic effect of smoking multiple cigarettes varying substantially in nicotine yield was investigated. Three treatments were imposed: nonsmoking at baseline, smoking six low-nicotine (0.8 mg nicotine) cigarettes (LOW), and smoking six high-nicotine (1.74 mg nicotine) cigarettes (HIGH). An initial increase of 6.8% in resting energy expenditure (REE) above baseline REE occurred after consumption of two consecutive cigarettes for both the HIGH and LOW treatments. With consumption of more cigarettes, the peak increase for the HIGH treatment was 9.3%, significantly greater than the peak of 5.9% for the LOW. Averaged over 2 hours, the HIGH treatment significantly increased REE by 6.9% and the LOW treatment significantly increased REE by 5.2%. Expired carbon monoxide (CO) measurements indicated that LOW cigarettes were smoked more aggressively than HIGH cigarettes. It was concluded that, initially, the nicotine yield of cigarettes is not an important influence on the thermic effect of smoking. But over a longer period and after multiple cigarettes, the nicotine yield may become an important influential factor.

Anabolic steroid usage in athletics: facts, fiction, and public relations.

Anecdotal evidence suggests the widespread usage of anabolic steroids among athletes (20–90%), particularly at the professional and elite amateur levels. In contrast, scientific studies indicate that usage is rare and no higher than 6%. Conclusions from scientific studies suggest that anabolic steroid usage declines progressively from high school to college and beyond; however, anecdotal evidence claims the opposite trend. In this clash between “hard” scientific data vs. “soft” anecdotal information, it is natural that professionals would gravitate toward scientifically based conclusions. However, in the case of anabolic steroids (a stigmatized and illegal substance), should word-of-mouth testimony from individuals closest to the issues—those who have participated in and coached sports, those who have served as drug-testing overseers, and journalists who relentlessly track leads and verify sources—be set aside as irrelevant? Not if a complete picture is to emerge. In this review, hard scientific evidence is placed on the table side-by-side with soft anecdotal evidence, without weighting or bias. The purpose is to allow the opportunity for each to illuminate the other and, in so doing, potentially bring us a step closer to determining the true extent of anabolic steroid usage in athletics.

The effect of smoking on energy expenditure and plasma catecholamine and nicotine levels during light physical activity

A number of studies have found that cigarette smoking causes an acute increase in resting energy expenditure, but the effect on energy expenditure during light physical activity is less clear. Since both smoking and activity have been shown to increase plasma catecholamines, these could produce additive effects on energy expenditure when smoking during light physical activity. In this study, the impact of cigarette smoking on energy expenditure, cardiovascular function, plasma nicotine and plasma catecholamine levels was determined in adult male subjects at rest and while engaged in light physical activity. Smoking at rest resulted in a 3.6% increase in energy expenditure above the resting baseline; whereas the increase in energy expenditure caused by smoking during light physical activity (compared with the light physical activity baseline) was 6.3%. This increase during light physical activity was significantly greater than the increase observed at rest (p < 0.025). As expected, plasma nicotine increased with smoking during both rest and light physical activity. An increase in plasma nicotine was associated with smoking during light physical activity. When this increase was adjusted as a covariate, the difference in smoking-related energy expenditure between light physical activity and rest disappeared, suggesting nicotine accounts for the effect. Plasma epinephrine and norepinephrine levels increased with smoking and showed a significantly greater increase during light physical activity compared to rest. Cigarette smoking caused a significantly greater increase in heart rate during light physical activity than it did while at rest, but there was no significant effect of smoking on mean blood pressure. It was concluded that there is enhanced energy expenditure associated with cigarette smoking during light physical activity when compared with smoking at rest which could be due in part to smoking-induced increases in circulating plasma catecholamines and perhaps nicotine.

Task Specific Changes in Maximal Oxygen Uptake Resulting from Arm versus Leg Training

Abstract The purpose of the present study was to investigate metabolic responses to submaximal and maximal exercise performed with trained versus untrained muscles. The subjects were 17 male college students randomly assigned to one of two experimental groups. Group II (N = 8) performed high intensity arm cranking exercise on a modified bicycle ergometer and Group II (N = 9) performed high intensity bench stepping with arms at sides to a height of 50·8 cm. Both groups trained three days per week for ten weeks. Each subject was tested twice at the beginning and twice at the conclusion of the ten week period. Discontinuous tests (5 min bouts) for determination of submaximal and maximal oxygen uptake ([Vdot]o2 max ) were randomly assigned and performed on bicycle and arm crank ergometers. respectively. [Vdot]o2 max (ml kg−1 min−1) significantly increased (19%) and submaximal heart rate (EKG) significantly decreased during arm testing of arm trained subjects. Similar results ( [Vdot]o2 max ml kg−1 min−1, incr...