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A W Gardner

Publications and source records attributed to A W Gardner.

At least 19 recordsLinked to original sources
PubMed1992

Resting energy metabolism and cardiovascular disease risk in resistance-trained and aerobically trained males.

The objectives of this study were (1) to examine differences in resting metabolic rate (RMR) and cardiovascular risk factors among aerobically trained (n = 36), resistance-trained (n = 18), and untrained (n = 42) young males; and (2) to investigate the influence of body composition, dietary intake, and VO2max as possible modulators of differences in cardiovascular risk among groups. Results showed that RMR, adjusted for differences in fat-free weight (FFW), was 5% higher in aerobically trained males compared with resistance-trained males (P < .01), and 10% higher than that in untrained males (P < .01). Plasma levels of cholesterol and low-density lipoprotein cholesterol (LDL-C) were comparable between resistance-trained and aerobically trained males, but were lower (P < .05) than those in untrained males. (The percent intake of dietary fat was related to plasma cholesterol [r = .32, P < .01] and LDL-C [r = .30, P < .01].) When compared with untrained males, fasting triglyceride (TG) levels were 39% and 43% lower (P < .01) in resistance-trained and aerobically trained males, respectively. When compared with untrained males, the fasting insulin to glucose ratio (I/G) was 45% and 53% lower (P < .01) in resistance- and aerobically trained males, respectively. Mean arterial pressure (MAP) was 7% lower (P < .01) in aerobically trained compared with untrained males. Statistical control for differences in percent body fat or percent intake of dietary fat diminished the differences among the groups for plasma lipids, blood pressure, and the I/G ratio. We conclude that aerobically trained and resistance-trained males have higher resting energy requirements independent of FFW compared with untrained males. Aerobically trained and resistance-trained young males have comparable and favorable cardiovascular disease risk profiles compared with untrained males, and this appears to be related to their low level of adiposity and low intake of dietary fat.

Adolescent↗
PubMed1992

Influence of endurance training on energy intake, norepinephrine kinetics, and metabolic rate in older individuals.

The role of physical activity in the regulation of energy intake in older persons is presently unclear. We therefore examined the influence of endurance training on voluntary energy intake and the associated changes in resting metabolic rate (RMR) and norepinephrine (NE) kinetics in seven healthy (six men, one woman) older individuals (69.4 +/- 2.2 years) under supervised living conditions. Energy intake was measured by covert assessment in a clinical research environment during: (1) a 10-day inpatient control period (no exercise); (2) a 10-day light exercise period (150 kcal per session, 3 times/wk); and (3) a 10-day moderate exercise period (300 kcal per session, 3 times/wk). RMR was determined after all three periods, and NE kinetics were assessed before and after training by infusions of tritiated NE ([3H]-NE). No significant change in energy intake was found between the control (2,378 +/- 130 kcal/d) and light exercise (2,449 +/- 104 kcal/d) periods, whereas energy intake increased 17% (P less than .01) during moderate exercise (2,785 +/- 161 kcal/d). Changes in RMR paralleled those of energy intake, as no differences were noted in RMR after control (1.03 +/- 0.12 kcal/min) and light exercise periods (1.04 +/- 0.12 kcal/min), but RMR increased 9% (1.13 +/- 0.14 kcal/min, P less than .01) after moderate endurance training, despite no changes in body composition.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Influence of aerobic capacity, body composition, and thyroid hormones on the age-related decline in resting metabolic rate.

It has been suggested that changes in fat-free weight may not fully explain the decline of resting metabolic rate (RMR) that occurs with aging. We therefore examined the hypothesis that a reduction in maximal aerobic capacity (VO2max) may partially explain the lower RMR in older men, after accounting for differences in fat-free weight and fat weight. We also considered differences in energy intake and plasma thyroid hormones as possible modulators of the age-related decline in RMR in men. Three-hundred healthy men (aged 17 to 78 years) were characterized for: (1) RMR (kcal/min) from indirect calorimetry; (2) body composition from underwater weighing; (3) maximal aerobic capacity from a test of VO2max; (4) plasma thyroid hormones (total triiodothyronine [T3], free T3, total thyroxine [T4], and free T4); and (5) estimated energy intake (kcal/d) from a 3-day food diary. A curvilinear decline of RMR with age was found (P less than .01), in which no relationship was found in men less than 40 years of age (r = .10, slope = 0.002 kcal/min/yr), whereas in men older than 40 years, RMR was negatively related to age (r = -.52, slope = -0.008 kcal/min/yr). After statistical control for differences in fat-free weight and fat weight, a negative relationship between age and RMR persisted (partial r = -.30, P less than .01). It was only after control for fat-free weight, fat weight, and VO2max (partial r = -.10, P greater than .05) that no association between age and RMR was noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Resting metabolic rate and the influence of the pretesting environment.

We examined the effect of pretesting environment on measurement of resting metabolic rate (RMR). RMR was measured in 18 older (66.1 +/- 1.4 y) individuals after an overnight stay in the Clinical Research Center (ie, inpatient) and after subjects transported themselves to the laboratory (ie, outpatient). Similar measurements were also performed after an 8-wk endurance-training program. RMR was higher (P less than 0.01) before exercise training in subjects who transported themselves to the laboratory (ie, outpatients; 4.9 +/- 0.13 kJ/min) than in inpatients (4.6 +/- 0.13 kJ/min) and after exercise training in outpatients (5.4 +/- 0.08 kJ/min) vs inpatients (5.0 +/- 0.13 kJ/min). Training increased RMR under both inpatient (10%; P less than 0.01) and outpatient (11%; P less than 0.01) conditions. We conclude that RMR is higher when measured under outpatient conditions in older volunteers. Therefore, when daily energy requirements based on the assessment of RMR are being estimated, the pretesting environment should be considered. However, the exercise-training-induced increase in RMR can be detected by using either an inpatient or an outpatient protocol.

Aged↗
PubMed1992

Comparison of three progressive exercise protocols in peripheral vascular occlusive disease.

Although claudication pain and hemodynamic responses to exercise are usually clinically assessed via graded treadmill walking, measuring these responses to other commonly performed tasks may yield a more nearly complete evaluation of peripheral vascular occlusive disease. Thus, the purpose of this study was twofold: (1) to determine the reliability of claudication and hemodynamic responses to level walking and stairclimbing and (2) to compare these responses with those obtained with graded walking at similar oxygen consumption. Ten patients with stable claudication symptoms performed graded walking, level walking, and stairclimbing progressive protocols with respective increases in grade, walking speed, and stepping rate on a modified stairclimbing device every two minutes. Similar peak oxygen consumption (13.60 to 14.18 mL/kg/min) was attained with the three protocols (P = NS). Reliability coefficients for the times to onset and to maximal claudication pain during level walking (R = 0.95 and 0.95, respectively) and during stairclimbing (R = 0.92 and 0.82, respectively) were similar to those previously obtained during graded walking. Reliability coefficients for foot transcutaneous oxygen tension during and following level walking (R = 0.78 to 0.96) and stairclimbing (R = 0.65 to 0.98) and for ankle systolic blood pressure following level walking (R = 0.95 to 0.97) and stairclimbing (R = 0.90 to 0.98) were also similar to those previously found with graded walking. Additionally, claudication and hemodynamic measurements were similar among the three exercise protocols. Thus, because graded walking, level walking, and stairclimbing progressive exercise protocols yield reliable and similar information about the hemodynamic severity of peripheral vascular occlusive disease, only one is needed for evaluation.

Aged↗
PubMed1992

Prediction of claudication pain from clinical measurements obtained at rest.

The ability to predict claudication pain during single-stage (S) and progressive (P) treadmill protocols from clinical measurements obtained at rest was examined. Peripheral hemodynamic measurements from the more severely diseased lower limb and medical history data were obtained from 56 claudicant patients during supine rest immediately preceding S (1.5 mph and 7.5% grade) and P (2 mph, 0% grade with 2% increase every 2 min) treadmill protocols. Distance walked to onset of claudication pain (CPD) and to maximal pain (MPD) during both protocols were recorded. The claudication distances during the S protocol were not correlated with either the peripheral hemodynamic or medical history variables. In contrast, CPD and MPD during the P protocol were predicted (P less than 0.05) by ankle/brachial systolic blood pressure index (ABI) (quadratic relationship), laterality of claudication pain (1 = unilateral, 2 = bilateral), and gender (1 = female, 2 = male) from the following regression equations: CDP (m) = 159.9 - (321.8 x ABI) + (445.6 x ABI2) - (93.5 x laterality) + (99.0 x gender), R = 0.74, R2 = 0.55, adjusted R2 = 0.53, SEE = 110.5, P less than 0.0001; and MPD (m) = 83.1 + (195.0 x ABI) + (174.0 x ABI2) - (76.4 x laterality) + (114.2 x gender), R = 0.76, R2 = 0.58, adjusted R2 = 0.55, SEE = 138.3, P less than 0.0001. It is concluded that the regression equations for the prediction of CPD and MPD may be used to quickly estimate the functional severity of peripheral vascular occlusive disease in clinical settings where treadmill testing is not feasible or is impractical.

Aged↗
PubMed1991

Effects of handrail support on claudication and hemodynamic responses to single-stage and progressive treadmill protocols in peripheral vascular occlusive disease.

Because handrail support reduces the energy cost of treadmill walking, claudication and hemodynamic responses of patients with peripheral vascular occlusive disease should also be affected. Furthermore, the reliability of the test results may be reduced unless the same pressure is applied to the handrails over repeated tests. The effect of handrail support on claudication and hemodynamic responses, and on their reliability, were examined during single-stage (2 mph, 12% grade) and progressive (2 mph, 0% grade with 2% increase every 2 minutes) treadmill protocols. Ten patients with stable disease performed both protocols 3 times, separated by 1 week, with and without handrail support. Claudication pain distance and maximal walking distance were greater (p less than 0.05) when handrail support was permitted, and they increased (p less than 0.05) over repeated tests of each protocol. No increase was noted over the tests without support. The responses and reliability of foot transcutaneous oxygen tension, ankle systolic pressure and ankle/brachial systolic pressure index after exercise to maximal tolerable pain were not affected by handrail support. Because claudication distances were altered, it is concluded that handrail support should not be allowed when assessing claudicants, unless balance cannot otherwise be maintained.

Aged↗
PubMed1991

Relationship between foot transcutaneous oxygen tension and ankle systolic blood pressure at rest and following exercise.

To determine whether foot transcutaneous oxygen tension (TcPO2) and ankle systolic blood pressure (SBP) measure similar aspects of peripheral vascular occlusive disease (PVOD), the authors examined their relationship at rest and following treadmill exercise. Thirty-seven PVOD patients (mean age 69.2 +/- 0.8 years) rested supine for twenty minutes, followed by a progressive treadmill walking test at a constant speed of 2 mph. The initial grade was 0%; this increased 2% every two minutes until maximal claudication pain (n = 19) or until the occurrence of such limiting symptoms as volitional fatigue (n = 6), ST segment depression (n = 4), dyspnea (n = 3), multiple premature ventricular contractions (n = 2), and angina (n = 2). Patients then rested supine for fifteen minutes. Foot TcPO2 was recorded before, during, and after exercise, whereas ankle SBP was measured before and after exercise. At rest, a curvilinear relationship was found between foot TcPO2 and ankle SBP (foot TcPO2 = 41.89 + 0.22(ankle SBP) + 0.0005 (ankle SBP2); SEE = 9.2, R = 0.64, R2 = 0.41, p less than 0.001). In contrast, the relationship was stronger and more linear during recovery, particularly at the sixth minute (foot TcPO2) = 8.33 + 0.35 (ankle SBP); SEE = 13.6, R = 0.86, R2 = 0.73, p less than 0.001). At rest, foot TcPO2 and ankle SBP characterized different aspects of PVOD because they shared only 41% common variance. During recovery, they provided similar information because up to 73% of the variance was shared. It is concluded that foot TcPO2 should also be used to assess PVOD patients because unique information is obtained at rest and values can be recorded during exercise.

Aged↗
PubMed1991

Progressive vs single-stage treadmill tests for evaluation of claudication.

The reliability of claudication pain and the metabolic and hemodynamic measurements of the lower limbs of patients with stable peripheral vascular occlusive disease (PVOD) were compared during and following single-stage (S) and progressive (P) treadmill tests. Ten patients (69.8 +/- 1.8 yr; X +/- SE) walked to maximal claudication pain twice a month for 4 months. Patients walked at 1.5 mph up a 7.5% grade (S test) and at 2 mph on a 0% grade, increasing by 2% every 2 min (P test). Distance walked to the onset of claudication pain (CPD) and maximal walking distance (MWD) were recorded. Foot transcutaneous oxygen tension (TcPO2) was measured before, during, and after exercise, while ankle systolic blood pressure (SBP) and the ankle-to-brachial SBP index (ABI) were measured before and after exercise. Intraclass correlation coefficients (R) of CPD and MWD during S tests were R = 0.53 and R = 0.55, respectively. In contrast, the respective R values during P tests were R = 0.89 and R = 0.93. Higher R values of foot TcPO2 were also obtained during and following P tests, while ankle SBP and ABI were highly reliable following both tests. It is concluded that the severity of PVOD is better assessed by P treadmill tests because clinical measurements are more reliable during exercise and recovery.

Aged↗
PubMed1989

Effect of endurance training on gross energy expenditure during exercise.

We compared the effect of endurance exercise training on gross energy expenditure (GEE) during steady-state exercise in 20 younger men (31.2 +/- 0.6 years) and 20 middle-aged men (49.2 +/- 1.1 years). The subjects trained for eight months. The training program consisted of three 45-min walking and jogging exercise sessions per week at an intensity of approximately 60-85% of the heart rate at peak VO2. We administered bicycle ergometer tests at 0, 4, and 8 months into training. Participants exercised at a power output of 100 W for 10 min using a pedaling frequency of 50 rpm. We determined GEE (kcal/min) by measuring the oxygen consumption and respiratory exchange ratio. We found a significant reduction (p less than 0.05) in GEE (0.7-1.3 kcal/min) following 4 months of endurance training in both age groups, with a further reduction (p less than 0.05) noted in only the middle-aged group at month 8. We found no difference (p greater than 0.05) in GEE between the younger and middle-aged men. We conclude that chronic exercise may modify GEE during a submaximal exercise bout and that this adaptation is similar in magnitude in younger and middle-aged men.

Adult↗
PubMed1988

A longitudinal study of energy expenditure in males during steady-state exercise.

Our purpose was to investigate longitudinal changes in gross energy expenditure (GEE) of 20 middle-aged and older men during submaximal exercise in 1969 and in 1985. GEE (kcal/min) was estimated using the caloric equivalent for each liter of oxygen consumed at the measured respiratory exchange ratio during submaximal exercise. The men performed a 10-min submaximal cycle ergometer exercise test at a power output (PO) of 100 W. Pedalling frequency was 50 rpm. Results showed a significant 5.9% decrease in GEE (p less than .01) from 8.5 +/- 0.8 (M +/- SD) kcal/min in 1969 to 8.0 +/- 0.4 (M +/- SD) Kcal/min in 1985. In addition, the effects of chronological age and leisure time physical activity on GEE were assessed and found to be nonsignificant, although a significant decrease in GEE over time (p less than .02) was observed in both groups. The present results support a decrease in GEE in middle-aged and older men over the 16-year time period. Furthermore, this decrease in GEE persisted regardless of chronological age or leisure time physical activity status.

Adult↗
PubMed1982

Absences attributed to respiratory diseases in welders.

Certified sickness rates of 36 male welders were examined for the period 1970-9. They were compared with 36 male controls from the same petrochemical plant, matched for age, smoking habits, duration of employment, and social class. Indices of severity (average annual duration), duration (average length of spell), and frequency (inception rate of spells and inception rate per worker) were calculated. Absences for all diseases were similar, but absences attributed to respiratory diseases were slightly higher in welders in severity, duration, and frequency. The proportion of days lost attributed to respiratory diseases was 2.3 times higher in welders compared with controls. This was due to a large increase in absences attributed to lower respiratory tract diseases, the ratio of welders to controls being more than four to one for both severity and inception rate of spells. The comparison between welders and controls in smokers and non-smokers confirms other studies which show that smokers tend to be more affected by welding fumes than non-smokers.

Absenteeism↗
PubMed1979

As I see it.

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Adult↗