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Biomedical subjects

J F Patton

Publications and source records attributed to J F Patton.

At least 55 records · Page 3Linked to original sources
PubMed1985

Maximal power outputs during the Wingate anaerobic test.

The purpose of this study was to determine the resistance loads which elicit maximal values of power output (PO) during performance of the Wingate test (WT). Nineteen male subjects (mean age, 25.1 yrs; mean VO2 max, 3.52 l/min) performed multiple WTs in a random order at resistances ranging from 3.23 to 6.76 joules/pedal rev/kg BW. Tests were carried out on a Monark cycle ergometer modified to permit instantaneous application of resistance. Revolutions were determined by a computer interfaced frequency counter. The mean resistances eliciting the highest peak power (PP) and mean power (MP) outputs were 5.65 and 5.53 joules/pedal rev/kg BW, respectively (average of 5.59 joules/pedal rev/kg BW). Both PP and MP were significantly higher (15.5% and 13.0%, respectively) using a resistance load of 5.59 compared to the Wingate setting of 4.41 joules/pedal rev/kg BW. The test-retest reliability for PP and MP ranged between 0.91 and 0.93 at both resistance loads. Body weight and thigh volume did not significantly estimate the individual resistances eliciting maximal POs. The data suggest that resistance be assigned according to the subjects BW but consideration be given to increasing the resistance from that presently used in various laboratories.

Adult↗
PubMed1984

Effects of acute cold exposure on submaximal endurance performance.

The purposes of this study were to assess VO2max and submaximal endurance time to exhaustion (ET) during acute cold-air exposure. Eight male subjects (means age = 19.9 yr) were alternately exposed in groups of four to chamber temperatures of +20 degrees C and -20 degrees C for 30 h each. A week was allowed between exposures. Maximum oxygen uptake was measured using a mechanically-braked cycle ergometer, and ET was determined on the same ergometer using a 17-min/3-min exercise/rest schedule until the subject was unable to maintain pedal rate. Maximum oxygen uptake was not significantly different between conditions: 3.43 +/- 0.09 l X min-1 at +20 degrees C and 3.35 +/- 0.10 l X min-1 at -20 degrees C. During endurance exercise, intensities equaled 77.1 +/- 1.4% and 78.9 +/- 2.0% of VO2max at +20 degrees C and -20 degrees C, respectively. Heart rate and VO2 values obtained between 8 and 10 min of the endurance run were not significantly different (156 +/- 2 bpm and 2.63 +/- 0.08 l X min-1 at +20 degrees C and 158 +/- 3 bpm and 2.65 +/- 0.11 l X min-1 at -20 degrees C). Endurance time to exhaustion however, decreased 38% (P less than 0.05) from 111.9 +/- 22.8 min at +20 degrees C to 66.9 +/- 13.6 min at -20 degrees C. The data support the contention that aerobic capacity is not altered by cold exposure but suggest a marked decrease in submaximal endurance performance.

Adolescent↗
PubMed1983

Effects of travel across time zones (jet-lag) on exercise capacity and performance.

Eighty-one healthy male soldiers, aged 18-34, were studied for 5 d before and 5 d after an eastward deployment across six time zones to determine the effects of translocation on exercise capacity and performance. Fatigue, weakness, headache, sleepiness, irritability, and other commonly reported symptoms occurred in the majority of subjects. Most, but not all, of the symptoms were diminished or absent by the fifth day following the translocation. Cardiorespiratory function and perception of effort during both submaximal and maximal treadmill exercise were unaffected. Isometric strength of the upper torso, legs, and trunk extensor muscles also was not changed. Dynamic strength and endurance of elbow flexors declined significantly. Dynamic knee extensor strength and endurance scores exhibited a progressive decrement prior to translocation and were inconsistent suggesting that the stress of repetitive testing outweighed any jet-lag effects on performance capacity. Performance times for a 270 m sprint were increased for the first 4 d following translocation as were times for a 2.8 km run on the second and third days and for a 110 m lift and carry on the third day after deployment. Times for a 6.5 m rope climb did not change. These findings indicate that certain symptoms and physiological capacities are affected as a result of multiple time zone translocation. However, the specific mechanisms involved, the factors influencing the magnitude of any physiological alterations, and the ultimate impact of these capacity changes on actual physical performance remain to be clarified.

Adaptation, Physiological↗
PubMed1983

Response of age forty and over military personnel to an unsupervised, self-administered aerobic training program.

The Army recently extended mandatory physical training and testing to include personnel 40 yrs of age and older. The purpose of this study was to describe the profile of aerobic fitness in a representative group from this age population and to evaluate the response of such a group to a self-administered, unsupervised training program. Maximal oxygen uptake (Vo2 max) and percent body fat (%BF) were assessed in 260 military personnel (40-53 yrs of age) before and after 6 mo of physical training consisting of a progressive walk/run mode of exercise. Before training the mean +/- S.D. for Vo2 max and %BF for all subjects was 38.1 +/- 6.2 ml/kg . min and 26.1 +/- 4.7%, respectively. Subjects were divided into three groups based upon their initial level of physical activity determined by interview as follows: inactive, moderately active and active. Upon retesting after 6 mo, 40% of the inactive group had not participated to any appreciable degree in the program and subjects of this group who did participate showed only a slight and insignificant increase (4.4%) in Vo2 max. The pretraining level of Vo2 max for the total population studied was similar to that reported in other studies on comparably aged subjects. However, changes with training were well below those seen with supervised group programs of 6 mo duration.

Adult↗
PubMed1982

Evaluation of a maximal predictive cycle ergometer test of aerobic power.

A maximal predictive cycle ergometer (CE) test for estimating maximal oxygen uptake (VO2 max) was evaluated in 15 male and 12 female subjects. The test consisted of pedalling a cycle ergometer (Monark) at 75 rev X min-1, beginning at an intensity of 37.5 watts and increasing by this amount each min until the subject could no longer maintain pedal rate. The highest work rate achieved was recorded as the endpoint of the test and used to construct regression equations to predict VO2 max. This was compared with two direct measures of VO2 max [an interrupted treadmill (TM) run and an interrupted CE procedure at 60 rev X min-1] and with the submaximal predictive test of Astrand-Rhyming. When compared to TM VO2 max, VO2 measured during the final 30 s of the maximal predictive CE test was 16.0% and 16.2% lower for males and females respectively; compared to VO2 max determined by the direct CE test, it was lower by 2.9% for males and 5.2% for females. Correlation coefficients for VO2 max predicted from the maximal predictive CE test and VO2 max measured directly by CE and TM were 0.89 and 0.87 for males and 0.88 and 0.83 for females (p less than 0.01), respectively. The VO2 max predicted from the Astrand-Rhyming test correlated significantly with VO2 max measured by CE and TM only in the male group. Test-retest reliability coefficients for intensity (watts) on the maximal predictive CE test were 0.95 and 0.81 for males and females respectively (p less than 0.01). The data suggest that this CE test gives a reliable and valid estimate of VO2 max.

Adult↗
PubMed1982

Effects of training with eccentric muscle contractions on exercise performance, energy expenditure, and body temperature.

To study the effects of exercise training with eccentric muscle contractions on body temperatures, energy cost, and performance capacity, six human subjects were tested before and after a 5-week training program of eccentric exercise. Exercise was performed as leg cycling on a motor-driven ergometer at power levels ranging 252-316 W. Training consisted of three sessions/week for 1 h/session. As a result of the training, VO2, fH, and mean skin temperature were lowered for each subject at the same absolute exercise intensities. Ability to continue exercise as indicated by endurance time improved with training. Before training, four subjects terminated exercise after 30 min because of localized leg exhaustion and one subject could not continue longer than 45 min. After training, all six subjects completed 45 min of the exercise test without difficulty. Esophageal and muscle temperatures evidenced no changes as a result of training. It was concluded that the inability of subjects to perform eccentric exercise in the untrained state was not related to muscle temperature.

Adult↗
PubMed1980

Quantification of petroleum-type hydrocarbons in avian tissue.

Methods were developed for the analysis of 16 hydrocarbons in avian tissue. Mechanical extraction with pentane was followed by clean-up on Florisil and Silicar. Residues were determined by gas-liquid chromatography and gas-liquid, chromatography-mass spectrometry. The method was applied to the analysis of liver, kidney, fat, and brain tissue of mallard ducks (Anas platyrhynchos) fed a mixture of hydrocarbons. Measurable concentrations of all compounds analyzed were present in all tissues except brain. Highest concentrations were in fat.

Adipose Tissue↗
PubMed1980

Aerobic power and body fat of men and women during army basic training.

Maximal oxygen uptake (VO2 max) and percent body fat (%BF) were assessed in 87 males and 57 females before and after 7 weeks of Army basic training. VO2 max was determined using a running treadmill protocol and %BF was measured by skinfold technique. VO2 max increased 3.7% (50.7 vs. 52.3 ml/kg.min) and 10.5% (36.9 vs. 39.3 ml/kg.min) for males and females, respectively, with training. %BF decreased 11% in males and 7.1% in females while body weight increased in both. Analysis of variance revealed that, while these changes were significant, there was no quantitative difference in the response of the sexes undergoing the same training program. The data suggest that basic training presents an effective physical challenge for those males and females who have a VO2 max below the ranges of 49-52 ml/kg.min and 38-41 ml/kg.min, respectively, upon entry. In addition, it effectively reduces BF content of those who initially possess high percentages and increases the lean body mass particularly in women.

Adipose Tissue↗
PubMed1980

Prevalence of coronary heart disease risk factors in a young military population.

This study was undertaken to determine the extent to which coronary heart disease risk factors are manifest in a young (17-35 years old) male military population. Approximately 360 individuals underwent medical and physical determination of body composition, blood cholesterol analysis, blood pressure measurement, history of smoking, and a maximal exercise stress test to assess maximal oxygen uptake (VO2 max) and the incidence of electrocardiographic abnormalities. Obesity (greater than 20% body fat), elevated blood cholesterol (greater than 200 mg/dl), and cigarette smoking (greater than 10 cigarettes/d) were the most predominant risk factors with incidences of 29, 32, and 36%, respectively. Only 2.4% of the sample had a positive stress test as indicated by an ST-segment depression of 1mm or greater. An inverse relationship between VO2 max and percent body fat was the only significant finding between level of aerobic power and risk factor prevalence. These data provide information on the prevalence of cardiovascular disease risk factors in an age group for which there has been only limited information.

Adolescent↗
PubMed1978

Psychological states and aerobic fitness of male and female recruits before and after basic training.

Psychological states and aerobic fitness were measured using a battery of psychological tests and a bicycle ergometer work test. A group of approximately two hundred male and female subjects were tested at the beginning of a six week basic training cycle and another group of two hundred were tested at the completion of basic training. A difference in mood, anxiety, self confidence and physical fitness was evident in the groups of male recruits, but not in the female recruits after training. A significant difference existed between males and females in terms of physical work capacity. These differences in work capacity and psychological responses should be considered in the assignment and selection of personnel for high work intensity military occupations.

Adolescent↗
PubMed1977

Perceived exertion of absolute work during a military physical training program.

The purpose of this study was to compare the rating of perceived exertion (PRE) and heart rate (HR) in two groups of 60 military personnel who differed in their level of fitness as determined by maximal oxygen uptake (VO2 max). At an initial testing period (T1), Group I represented a sample of personnel not participating in a training program while Group II had engaged in an endurance program (2--4 mile run/day) for 5 months. Six months later (T2), Groups I and II were retested after having participated in the program for 6 and 11 months, respectively. RPE and HR were measured at the end of each min of a 6 min run at an absolute workload of 6 mph, 0% grade on the treadmill. At T1, Group II had a significantly lower HR at each min of work but no difference existed in RPE between groups at any time during the run. At T2, both groups showed a significant decrease in HR and RPE during each min when compared lobgitudinally. The data suggest that the perception of the intensity of absolute work does not differ in groups differing in their level of fitness when studied cross-sectionally. However, significant reductions in perceived exertion occur following physical training.

Adult↗
PubMed1977

Cross-sectional and longitudinal evaluations of an endurance training program.

A comparison of the cardiorespiratory responses obtained using both a longitudinal and cross-sectional evaluation of an endurance training program was made in two groups of 60 young male military personnel. Both groups were initially tested (T1) and then retested 6 months later (T2). At T1, Group I was a sample of personnel not participating in a training program while Group II had undergone a 5-month endurance program (2-4 mile run/day). At T2, Groups I and II had been participating in the program for 6 and 11 months, respectively. Testing consisted of sub-maximal and maximal determinations of VO2, VE and heart rate (HR) using an interrupted treadmill test. VO2 max was 11% greater in Group II compared to Group I at T1 and increased 10% in Group I at T2. Similar results were also seen for HR submax, HR max and VE max. These results show that similar values indicative of an improved level of cardiorespiratory fitness can be obtained using either a cross-sectional or longitudinal design when relatively homogeneous groups are studied.

Adolescent↗