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The effects of enforced exercise on performance and carcass composition of growing pigs were studied on eight crossbred gilts. Four animals were exercised periodically on a treadmill from a liveweight of 12 to 60 kg; the remaining four animals acted as a control group. Pigs were exercised three afternoons a week for a period of 60 min at a speed of 2 km/h. Animals were slaughtered at a liveweight of 60 kg and the left side of each carcass dissected into individual muscles, fat and bone. Proximate analyses were conducted on two selected muscles. There were no significant differences between the groups overall (0 to 9 wk) in feed intake, weight gain or efficiency of feed conversion. From 7 to 9 wk the exercised group grew at a significantly faster rate and consumed significantly less feed per kg liveweight than the control group. The enhanced rate of gain of the exercised group during this period occurred even though feed intakes of the two groups were similar. It is suggested that this improved gain may have been due to a compensatory growth effect associated with a relative decrease in the severity of the exercise treatment as the pigs increased in size. Exercise treatment had no significant effects on carcass weight or on the weight of the following organs: blood, heart, liver, kidneys, spleen, alimentary tract tissue and alimentary tract fat. Similarly, enforced exercise had no significant effects on either the proportion of carcass muscle, fat and bone or on muscle distribution. Chemical analysis of M. psoas major from exercised animals showed a significantly higher protein and lower moisture content, respectively, than those from control animals. Composition of M. biceps brachii in exercised and control animals was similar.

Male rats of 90, 150, 300, 450 or 600 days of age were placed into sedentary or physical training experimental groups. Experimental animals ran daily for 20 min at 10–20 m/min on a treadmill set at an 8-degree incline. The experimental period lasted at least 300 days. Surviving rats from each group were chosen randomly and sacrificed at 150-day intervals up to 1,050 days of age. Muscle and organ weights were analyzed by grouping animals according to their age at death and also according to their age at the initiation of the training program. Muscle and organ weight data suggest that training has a minimal affect on rats past a threshold age (approximately 450 days of age), and initiation of a training program at a late age (approximately 600 days of age) may adversely affect the rat. When the effects of age and training are combined, those attributable to age seem to be more important, supporting the view that there is a threshold age beyond which the initiation of a training program no longer affects the muscle and organ weights.

The biomechanics of overground running were compared before and after a month training period which comprised 16 thirty-minute sessions of short duration (5 seconds work, 10 seconds rest) high intensity (4.69 m/sec 20-25% grade) interval treadmill work. For the eight subjects filmed there were no significant changes in support and non support time, stride length or stride rate while running at 3.58 m/sec that could be attributed to the treadmill training regime. This training programme produced significant gains in aerobic and anaerobic metabolism but was not an effective developer of speed.

Caffeine was examined for the effect upon the running performance on a treadmill in two trained dogs. A preliminary experiment was performed to find out running speeds at which the steady adaptation to exercise was broken up. Runs of 15-minute duration at speeds of 220 and 235 m/min in dog 1 and at a speed of 160 m/min in dog 2 (at a grade of 0% in both dogs) were determined to be employed in an experiment with caffeine. Caffeine was administered intravenously at single doses of 2.5, 5.0, and 7.5 mg/kg in the form of a mixture of caffeine and sodium benzoate. Runs were started 10 minutes after administration. Caffeine improved the running performance markedly at a strenuous work rate in dog 1, even at such a small dose as 2.5 mg/kg. On the contrary, it had an obscure performance-increasing effect on dog 2, even at such a large dose as 7.5 mg/kg, although the dog was placed on exercise at a much lower work rate than dog 1. The effect of caffeine would be evaluated only qualitatively, because of individual differences in this effect from dog to dog.

Oxygen uptake one minute after starting to walk on a treadmill with fixed settings of speed and grade ( V ˙ O 2- 1) was found in 24 normal men and 5 normal women to be linearly related to the power requirement against gravity (P) in which P = weight × grade × walking speed. From this finding a standardized determination of V ˙ O 2- 1 at P = 1072 kg-M/min was devised with averaging of the first two acceptable determinations. Twenty-five normal men and 40 men with coronary artery disease (CAD) were studied. Abnormally low V ˙ O 2- 1 scores were found in 21 of the CAD patients. In seven patients studied with the technique of the single breath cardiac output (CO), correlation existed between V ˙ O 2- 1 and cardiac output at one minute (CO-1). Low values of V ˙ O 2 -I occurred in 12 of 16 patients with elevated values of left ventricular end-diastolic pressure (p < .05). There was no correlation between V ˙ O 2- 1 and the number of vessels involved. Data suggest that impaired ventricular performance results in a delayed rise of V ˙ O 2 . The latter can be observed in about 50 percent of patients undergoing coronary angiography.

Twenty-five patients had myocardial blood flow reserve determinations (percentage increase in myocardial blood flow with stress), treadmill exercise tests and coronary and bypass cineangiography pre- and postaortocoronary bypass surgery. Twenty of the patients had the postoperative studies performed three months after operation, three at two months and two at five and six months, respectively. Eleven of the 25 patients had all significant coronary artery obstructions (75% or greater) bypassed and all grafts were open at the time of restudy. Preoperatively, blood flow reserve had been abnormal in nine and all had positive treadmill tests. Postoperatively, all eleven patients had normal myocardial blood flow response to stress and treadmill tests were negative in ten (one patient was not restudied on the treadmill). In six patients, no patent grafts could be demonstrated. These patients continued to show abnormal blood flow reserve and positive treadmill studies. Eight of the 25 patients had partial revascularization in that some grafts were open, some closed, and some significantly occlusive lesions were not bypassed. Four of these eight patients had normal flow and treadmill studies and the remainder continued to have an abnormal response to one or both of the measurements. The relationship between treadmill exercise response, myocardial blood flow reserve, and graft patency was significant at the 0.005 level for patients with all grafts open or closed. No significant correlation was obtained between any of the measurements in those patients with partial revascularization. The data indicate that successful aortocoronary bypass grafting provides myocardial revascularization as reflected in a return to normal of the myocardial blood flow reserve and response to treadmill stress testing.

Maximal oxygen uptake V O O2 max ) and functional aerobic impairment (FAI) were determined by treadmill test in 42 men with coronary heart disease and in 11 slightly older healthy men. Patients were separated according to occurrence or nonoccurrence of angina with exercise. At rest and at four levels of submaximal exercise on a bicycle ergometer, cardiac output (Q), using the direct Fick principle, heart rate (HR), mean systemic and pulmonary arterial pressures, and arterial-mixed venous oxygen difference (A-V O 2 D) were evaluated in relation to relative aerobic requirement (% V o o2 max ). Q was highly correlated with V o o2 , and both the level and the rate of change of Q were lower in patients with angina at all submaximal workloads. Stroke volume (SV) and HR were significantly restricted at the higher workloads. Although peripheral resistance was increased, there was no compensatory increase in A-V O 2 D. Both restricted SV and reduced HR are responsible for cardiovascular components of the abnormal FAI found in patients with myocardial ischemia due to coronary arterial disease.

The effect of an increased body temperature (T r) elicited by prolonged heavy exercise at normal ambient temperature in absence of any heat stress, on the maximal aerobic power ( $$\dot V_{O_2 \max } $$ ) and on heart rate (HR) has been studied. The prolonged exercise consisted in running for 1 hr on a motor driven treadmill, this leading to an average increase of T r of 1.2° C. Oxygen consumption ( $$\dot V_{O_2 } $$ ), ventilation (V I ), HR and T r were measured at rest and every 10 min during the prolonged exercise. Before and after this exercise indirect measurement of $$\dot V_{O_2 \max } $$ were made. After the exercise, HR in submaximal exercise was increased, the increase being less pronounced the heavier the exercise. The HR increment was 17.5 beats/min per 1° C rise in T r in the exercise involving an oxygen comsumption of 22 ml/kg·min and it dropped to 7.5 b/min · °C when the O2 consumption increased to 32.4 ml/kg · · min. $$\dot V_{O_2 \max } $$ as calculated indirectly from HR values in submaximal exercise remained essentially the same before and after the treadmill run.

In animal and human populations the resting level of muscle glycogen is an important determinant of an exercise response. Since the hormonal mechanisms are obscure, the effectof a single bout of exercise on muscle and liver glycogen levels was studied in adrenalectomized, adrenaldemedullated, and sham-operated Sprague-Dawley rats. Plasma FFA levels, 11-OHCS levels and blood glucose values were also measured in rats who were approximately 50 days old at the time of surgery. One week after surgery, the animals were “exhausted” by running on a treadmill for 60-70 min at grades between 0-15% and speeds ranging from 8.8 to 22.8 m⁄min. The plasma 11-OHCS and FFA levels indicated that the surgical and exercise procedures were effective and strenuous. Resting muscle glycogen results from nonexercised animals showed that the adrenal-demedullated group had the highest concentration of all groups.Immediately after exercise,liver and muscle glycogen stores were significantly reduced in every group whilethe plasma FFA...

Methods of exercise testing are considered in relation to physiologic types, clinical applications and objectives, physiologic differences in end points and inferences, and comparison of oxygen requirements and circulatory responses. Hazards and safety precautions are cited. The multistage treadmill test of submaximal and maximal exercise is described in terms of oxygen requirements, measurement of maximal oxygen uptake, approach to maximal uptake, determination of functional aerobic impairment and assessment of circulatory and electrocardiographic responses. Initial findings are presented of a new, prospective community study (“Seattle Heart Watch”) designed to test the hypothesis that specific persons at risk for future angina pectoris, myocardial infarction or sudden death can be identified by this method.

Dogs were used to record the electromyographic (EMG) activity of fifty skeletal muscles and 16-mm motion pictures in the treadmill galloping and a cyclogram in a level-ground galloping. Based on the results obtained, discussion was made on the movement of the limbs in walk, trot, and gallop. Gallop is an asymmetrical gait. A trailing limb and a leading one were proved to have essentially the same movement, though the movement of the axial skeleton produced some differences between them. Each limb had essentially the same movement throughout the gaits: walk, trot, and gallop. Of course, each gait seemed different at a glance and had actually different EMG activity patterns and change of joint angles. These differences were, however, decorated by the speed of locomotion and the movement of the axial skeleton of each gait. Just before landing, the hind limb which landed on the ground nearest to the vertical line drawn from the center of gravity of the body might make the structure as a weight-bearing bracer which also operated as a lever. The fore limb which landed on the ground most apart from this vertical line might do that after landing. The fore limb might play a more important role as a balancer than a propeller.

Experiments were performed to determine whether rats whose spontaneous locomotor activity had been decreased by the placement of bilateral electrolytic lesions in the tuber cinereum of the hypothalamus could be forced to run on a treadmill. All rats with small medial lesions, some rats with large medial lesions, and most rats with lateral lesions needed no more prodding to run on the treadmill than they needed before receiving their lesions. While some rats with large medial lesions and some with lateral lesions usually needed more prodding to keep them running, they, nevertheless, were able to run on the treadmill; in fact, most of these rats occasionally ran as well as did the control rats. Only one rat, a rat with large medial lesions, refused to run. These data suggest that a lack of ability to run cannot explain the hypoactivity observed in these rats.

Experiments were conducted to evaluate the effect of exercise, housing practices and calcium source on the bone strength of laying hens. Dolomitic limestone was found to be inferior to calcium carbonate as a calcium source as indicated by weaker tibia strength when fed in equal or ⅓ higher amounts. Possibly the poorer availability of calcium was the cause of weaker tibias. Floor birds were found to have higher tibia breaking strengths and less broken bones compared to caged birds. Greatest differences were noticed in the number of broken wings, suggesting lack of exercise in cages as being a factor in bone weakness. Further studies involving daily exercise of caged birds in a treadmill resulted in higher humerus strength supported this conclusion. Floor birds had significantly higher (P A device for exercising experimental birds is described.

Ventilatory gas exchange ratio (R), VO 2 , ventilation (V E ), respiration rate (RR), rectal temperature (T re ), and heart rate (HR) were determined for four acclimatized subjects during intermittent and prolonged exercise on a treadmill at 24° and 45°C (dry) as follows: 1) 8 cycles (10 min. exercise and 5 min. rest), and 2) prolonged exercise lasting for 90 min. While during intermittent and prolonged exercise, VO 2 and V E did not differ in the heat, RR, T re , HR and the respiratory dead space were higher in the hot ambient environment. After steady-state attainment, exercise R was higher in the initial as compared to the last cycles with higher values in neutral as compared to the hot ambient condition. It was concluded that heat was more effective than time in lowering the R, probably with a greater dependence on fat oxidation in the latter exercise cycles which seemed to be more pronounced in the heat.

In order to study the relationship between bicycle-ergometer test and treadmill test, various parameters of cardiac function were compared before, during and after giving multiple loads in identical normal subjects and cardiac patients.Method: Utilizing bicycle-ergometer, 5-minutes 50w/sec exercise was initially loaded in 49 cases consisted of 10 normal subjects and 39 patients with coronary heart disease (17 cases), valvular heart disease (16 cases) and hypertensive heart disease (6 cases) who were also divided into groups as Classes I (10 cases), II (22 cases), III (7 cases) of New York Heart Association (NYHA).After full rest, 5-minutes 75w/sec exercise was then loaded in well-tolerated cases of 50w/sec exercise loading test, or 5-minutes 25w/sec exercise in non-tolerated cases.3-7 days later, utilizing treadmill, 5-minutes 5°·30m/min exercise was loaded in these 49 cases. After full rest, 5-minutes 10°·50m/min exercise was loaded in well-tolerated cases of 5°·30m/min exercise loading test, or 5-minute 2.5°·20m/min exercise in non-tolerated cases.In each test, the exercise loading was stopped when severe dyspnea, fatigue, palpitation, dizziness, slight chest pain, etc appeared, or S-T segment depression exceeding 2.0mm, or S-T segment elevation exceeding 2.0mm was observed on ECG.Results: No significant difference in relative metabolic rate (RMR) and oxygen consumption were observed between 50w/sec and 5°·30m/min method, and between 25w/sec and 2.5°·20/min method. However, the RMR and the oxygen consumption in 75w/sec method were significantly lower than those in 10°·50m/min method.Analysing the data of change in heart rate in exercise, maximum heart rate, 3-minutes total heart rate in recovery, physical fitness index (PFI), oxygen pulse, oxygen debt and ECG findings, it was found that the amounts of load of 50w/sec and 25w/sec were almost equal those of 5°·30m/min and 2.5°·20m/min, the amounts of load of 10°·5m/min was stronger than those of 75w/sec.In 50w/sec method, severe complaints appeared in 20% of Class II (interrupted cases) and 83.3% of Class III patients. In 5°·30m/min method, severe complaints appeared in 20% of Class II (interrupted cases) and 28.6% of Class III patients.Dullness of the lower-extremities and palpitation appeared much more frequently in bicycle-ergometer method than in treadmill method in the extent of 50-75w/sec or 50°·30m/min-10°·5m/min. Dyspnea appeared in both methods in similar frequency.The exercise loading test using bicycle-ergometer was not suitable for some women, middle-or more than middle aged, because of their unskillfulness.It was concluded that the treadmill method is more natural exercise loading test than bicycle-ergometer method for Japanese.

The ventilatory response to exercise was studied on awake dogs trained to run on a treadmill. The exercise were performed at a grade and speed inducing an increase in the energy metabolic level up to 7 times the resting value. The roles of nervous and humoral stimuli in ventilatory control were analyzed by measuring ventilatory flow rate, tidal volume and respiratory frequency during exercise in three gaseous environments (air, hypoxia and hypercapnia) before and after carotid chemodenervation. At the start of exercise, the marked early rapid change of ventilation was unaffected by the gaseous environment. The terminal fall of ventilation was smaller than the early increase and its magnitude was decreased by hypoxia and hypercapnia. The 02 stimulus was lessened by exercise. For given levels of energy metabolism and of rectal temperature, hypoxia and hypercapnia altered the ventilatory pattern: the ventilatory frequency was decreased while the ventilatory flow rate and tidal volume were increased, inducing then an increase in alveolar ventilation. Hyperpnea related to hyperthermia was unaffected by the gaseous environment. Sinocarotid chemodenervation altered the exercise ventilatory pattern: for a given energy metabolism level, tidal volume was decreased and respiratory frequency increased. The transient rapid changes of ventilation of both the beginning and the end of exercise were altered.

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...

The relationship of ejection time to heart rate was examined in 19 ath-letes, 21 sedentary normal subjects and 19 patients with anginal ischemic heart disease.Exercise tests were performed using the step test, the bicycle ergometer and the treadmill. Regression analysis was applied to the data by regressing ET on HR and delta ET on delta HR.No significant differences were demonstrated between these groups even though the coronary insufficient patients manifested ischemic S-T segment changes and angina. Slight differences existed between the normal and is-chemic groups when the delta ET-delta HR relationship was examined, but the variance of the data challenged the significance.The data indicated that at any level of heart rate induced by exercise, the measurement of ejection time will not distinguish between trained athletes, normal sedentary subjects or coronary insufficient patients.

Slow electrical activity was recorded from the dorsal hippocampus in rats during running in a motor-driven wheel, swimming, conditioned avoidance (running, jumping), lever pressing for food and sleep, and in cats during walking in a treadmill, eating and lapping milk. Large-amplitude clear rhythmical slow activity (RSA) was recorded from the hippocampus proper and smaller amplitude RSA and fast activity was recorded from the dentate gyrus-CA 4 area. This was also observed in acute rat preparations. During large movements (run, jump) RSA amplitude was up to 6 times greater than during small movements (head turn, lever press). Initiation of movement was associated with an increase in RSA frequency, which was most pronounced with forceful movements. During steady running or swimming in the rat frequencies of 7–9 Hz were recorded and during prolonged running up to 8 hr RSA was unchanged. RSA frequency did not vary with the speed of steady running or steady locomotor patterns of swimming, walking, trotting or galloping. RSA frequency and amplitude may reflect different mechanisms; frequency was normal after hippocampal electrographic seizures, amplitude was depressed; frequency varied directly with core temperature (27–42° C) but amplitude remained constant. Increases in RSA frequency and amplitude during paradoxical sleep were associated with muscular twitches, suggesting that forebrain motor mechanisms were activated. The results are interpreted in support of the idea that RSA is related to higher level control of voluntary movement.

THIS paper reports a statistical study of the comparability of certain maximal and submaximal data from a number of work capacity tests. The results indicate that submaximal tests may be expected to yield information which is reasonably comparable to that from maximum tests in specific respects. In consequence of this finding epidemiologic studies of coronary heart disease may be encouraged to use modified work capacity tests (with no hazard to subjects) to look for a possible inverse relationship between risk of the disease and cardiovascular fitness. This so far unexplored avenue of investigation would appear indicated by the findings of numerous studies of differential risk in occupationally defined classes of physical activity [l-18]. Maximum work capacity tests, as described by BALKE [19], represent a relatively short experimental procedure for stimulating a subject to his maximal functional capacity for physical work. The subject works on a treadmill or electrically braked bicycle ergometer at a measured, gradually increasing work load until specified physiological criteria are reached. Pulse frequency, blood pressure, respiratory volume, concentrations of oxygen and carbon dioxide in the expired air, respiration frequency, and ECG are monitored and recorded throughout the test. BALKE [19-201 found that his subject’s response to the test conditions follow a distinct course or pattern. In the long first segment, all measured functional values increase in an approximately linear way with increasing work load. In the following short segment before test termination, the linear relationships are disturbed. The heart rate at this juncture for young healthy male subjects was about 180 beats per minute. Analysis of the changes occurring here indicated that the physiologic limits of effective circulatory and respiratory adaptation to increasing oxygen demand had been exceeded; further increase of work was possible only by exploiting oxygen debt capacity. A heart rate in the neighborhood of 180 thus appears to represent aerobic crest load for the population of young healthy men. The design of the specific work capacity test used is such that time in minutes on the treadmill and work load for an individual are equivalent, except for a proportionality factor. This is shown in the next section. Time to heart rate equals 180 thus provides a

Forty-six patients with clinically significant peripheral atherosclerosis were randomly allocated into two groups; one receiving tablets of betapyridyl carbinol, up to 1800 mg daily, the other receiving a placebo. Patients were assessed clinically and their performance on a treadmill measured over intervals for two years. Plasma lipids were also measured. There was a slightly significant improvement in clinical findings after two years in those receiving drug treatment but no difference in symptoms. Treadmill performance appeared to improve equally in both placebo and drug treated groups. The plasma cholesterol fell significantly in the treated group compared the controls but the plasma triglycerides were not altered. Drop-outs from the trial did not differ significantly between the two groups. Two cases of hepatocellular dysfunction were attributable to betapyridyl carbinol.

Twelve young men including six trained endurance runners and six non-runners, were tested once in each of three treatment situations to determine the effectiveness of oxygen inhalation as an aid to recovery. The exercise test involved two runs of 5 min. each on a motor-driven treadmill. The treadmill was set at level grade and a speed of 8mph. After the first run, one of the treatments was administered. The treatments consisted of oxygen, a placebo tank of compressed atmospheric air, and ordinary atmospheric air. Immediately after a 1-min. inhalation period, the second 5-min. run followed. Heart rates were monitored throughout the testing period, and recovery oxygen consumption and ventilation rate were measured after the second run. The inhalation of oxygen did not appear to be of any physiological aid to recovery. Although not of statistical significance, larger pulse decreases were recorded on the non-runners during the inhalation of oxygen. Exercise pulse rates indicated that the exercise tes...

Tryptophan and quinolinic acid, inhibitors of gluconeogenesis, were used to block the removal of lactate by the liver in order to investigate the involvement of the Cori cycle in oxygen debt. Five male, mongrel dogs were run on a treadmill at 4 mph with a 20 percent grade for 19 min. The mean exercise $$\dot V_{O_2 }$$ was 80.67±3.11 ml/kg/min for the control tests while peak arterial lactate values ranged from 3.83 to 4.98 mM/l. When removal of lactate by the liver was blocked, oxygen debt showed a mean reduction of 44 percent. Moreover, oxygen consumption during the last minute of exercise was reduced by 11 percent. Fasting (72 h) was used in 1 dog to prevent the accumulation of lactate during exercise. This procedure reduced oxygen debt to the same level as when the removal of lactate by the liver was blocked with tryptophan and quinolinic acid. The data show that the lactacid as well as the alactacid component is involved in oxygen debt when lactate is being removed by the liver during the recovery period following exercise.

Twenty-seven members of the 1970 Big 33 football team in Pennsyvania participated in a progressive work test on a treadmill designed to assess their work capacity as well as their capacity to deliver oxygen to working muscle. All were recent high school graduates. Anthropometric measurements revealed that interior linemen and linebackers were physically larger and possessed more body fat than backs and ends. Average aerobic capacity (maximal oxygen intake) for all players was approximately 50 ml/kg/min, an average regarded as relatively low, particularly for the backs and ends who consistently participated in run and pass plays. The relatively moderate level of work and aerobic capacity observed for these athletes is a reflection of their conditioning regimen which consisted mainly of weight training and sprint running, with little emphasis on development of cardiorespiratory endurance.

The purpose of this study was to compare three methods of relieving fatigue between bouts of strenuous exercise—rest, abdominal cold packs, and cold showers. Fifteen subjects were used in the study; each subject participated in each of the three treatments, making a total of 45 measurements. The subjects ran on a treadmill which was set at 8 mph with a 10 percent elevation, until their pulse rates reached 180 beats per minute. One of the three treatments was then applied for 10 min., after which the subjects engaged in a second treadmill run until heart rates reached 180 beats per minute. The time of the second treadmill run was the main criterion measure. A complete randomized block design was used to test the differences among the three treatments for statistical significance. The Newman-Keuls sequential range test was employed to test differences between all possible pairs of treatment. Abdominal cold packs proved to be the most effective treatment, with the cold shower second and rest third.

Silverman, M., Konig, P., and Godfrey, S. (1973). Thorax , 28 , 574-578. Use of serial exercise tests to assess the efficacy and duration of action of drugs for asthma. A technique for studying the efficacy and duration of action of drugs used in asthma by means of exercise tests is described. The patient runs for six minutes every two hours, four times a day, on a treadmill at a constant speed and slope. The test drug or its placebo is given immediately before the first test of the day, and their effects on the exercise-induced asthma are compared. This enables the immediate protection and duration of action of the test drug to be measured. No change in the severity of post-exercise asthma was found when serial tests were performed during one day after administration of a placebo. In a selected group of 14 children studied with disodium cromoglycate, three patterns were seen. In five patients the drug afforded prolonged benefit, in five others the protection was very short-lived, and in four patients it did not seem to be better than the placebo. The use of the tests is also illustrated with respect to bronchodilator drugs.

SummaryElectrocardiograms obtained during exercise on a treadmill and on a bicycle ergometer have shown that the relation between the QT and RR intervals can be represented by the equation QT = K+ 0.5 RR when K has a value of 70 msec. This equation was the same in trained and untrained subjects. During recovery from exercise the RR intervals lengthened much faster than the QT intervals.The alveolar pCO2 increased during the exercise while QT shortened. Immediately after exercise the alveolar pCO2 continued to increase at a time when the QT was no longer shortening.

Four techniques were compared for effectiveness in promoting recovery during a ten-minute rest period between experimental work periods. The four techniques were: (a) lying supine, (b) elevation of arms and legs, (c) slow movement, and (d) watching sound movies. Two swimming subjects, two track subjects, and two treadmill subjects each completed 32 double work periods. Elevation of the arms and legs proved to be the most effective recovery technique for these subjects but it was not significantly superior. Slow movement during recovery resulted in significantly less oxygen debt being repaid in the treadmill subjects.

Cardiac performance in 25 male and 40 female cardiac patients with atrial fibrillation was compared with that of age, sex, and function-matched controls with sinus rhythm. All had rheumatic valvular heart disease treated with digitalis. Multistage maximal exercise was tested on a motor-driven treadmill with increasing work loads every 3 minutes to the limits of fatigue. Mean heart rates of patients with atrial fibrillation were greater at rest, at all levels of exercise, and immediately after it regardless of sex or anatomic lesion; however, recovery heart rate was significantly higher in the males than in the females with sinus rhythm. As is true for normals, mean duration and intensity of exercise was greater in male than in female cardiac patients regardless of rhythm or anatomic lesion.

Summary. Effect of thermal stress (Finnish Sauna-bath) and muscular exercise (on treadmill) on the rise in body temperature, on the sweating rate, and electrolyte and lactate content of sweat is studied. In one half of the experiments, hypoglycaemia was induced by intravenous injections of insulin. There are no significant differences in the rate of sweating and in the composition of sweat during insulin hypoglycaemia and during euglycaemia. In the lactiite content of sweat there is some tendency to increased values with decreased blood sugar concentrations. The rise in body temperature under insulin hppoglycaemia is significantly lower than in experiments without insulin injection. The reason for this observation is briefly discussed.

Four subjects worked on a treadmill or a bicycle ergometer for 180 min at oxygen uptakes of 75% of the individual's max Vo2; after 90 min rest, the exercise was resumed and a maximal work load was tried. Repeated circulatory studies were made. The body weight decreased 3.1 kg (3.2–5.2%), but the reduction in blood volume was less than 5%. During submaximal exercise the major change in the hemodynamic response was a decrease in stroke volume (from 126 to 107 ml). Oxygen uptake and cardiac output increased slightly. There was a decrease of about 10% in systolic, diastolic, and mean arterial blood pressure during the 180 min of exercise. When the work was performed in a supine position there was the same reduction in the stroke volume as in the sitting work position. At the maximal work oxygen uptake, cardiac output, heart rate, and blood pressure attained almost normal values but there was a marked decrease in both work time and blood lactates. dehydration; blood volume; arterial blood pressure; circulatory reaction Submitted on January 31, 1964

1. 1. Oxygen consumption, body temperature and evaporative water loss were measured at various ambient temperatures between 5–35°C while the chipmunks were running in a treadmill respirometer at 20, 30, 40 or 50 m/min. 2. 2. Body temperature increased with increasing ambient temperature but was independent of velocity of running except at an ambient temperature of 35°C. 3. 3. Oxygen consumption increased with velocity at a given TA to maximum levels which were dependent upon TA. 4. 4. Total dotVO2—resting dotVO2 (cost of running) showed that the heat produced by running partially substituted for that due to cold at high velocity, but at low velocity running the heat produced by running adds to that due to cold. 5. 5. The evaporative water loss was increased five to seven times over resting levels while the animals were running 20 m/min at ambient temperatures of 15, 30 and 35°C. 6. 6. At a given TA the thermal conductance of chipmunks was greater during activity than when at rest and increased curvilinearly with TA at a given velocity.

The purpose of this study was to isolate relationships between psychomotor responses and personality structure. Fifteen subjecs were administered the Thurstone Temperament Schedule. Stress was provided by a heat chamber with an ambient temperature of 110 F (30–50 percent R.H.) and walking on a treadmill which moved at 4 mph at zero grade. Analysis of the data permits the following conclusions: (a) two-hand coordination showed a positive significant relationship to the measure of competitiveness; (b) tapping showed a positive significant relationship to the vigorous and sociable traits; and (c) a significant positive relationship between strength and the active trait was found. Hand and arm steadiness had a significant negative relationship with the emotional stability trait.

ALTHOUGH various exercise tolerance tests are widely used in clinical practice and medical research to estimate physical and physiological functions (see, for example, Bard, Chapter 47, 1956; and Astrand, 1956), they seem to have found limited application in the animal sciences. In poultry, forced physical activity has been used in connection with such studies as: stress and adrenal hormone interaction (Garren and Shaffner, 1954; Connor and Shaffner, 1954); lipid metabolism and atherogenesis (Warnock et al., 1957; Wong et al., 1959); hematological changes (Anderson et al., 1959); blood uric-acid levels (Hudson and Taylor, 1960); feather removal (Knapp and Newell, 1961); and the mortality differences between genetically selected hyper- and hypotensive strains (Sturkie and Textor, 1961). However, apart from the data supplied by Garren and Shaffner (1954) for the growing chick exercised in a revolving drum, little appears to be known of the characteristics involved in the bird’s resistance to muscular fatigue….

To evaluate the improvement in myocardial oxygen delivery following saphenous vein graft surgery (SVG) for angina pectoris (AP), 46 patients underwent a multistage treadmill test of maximal exercise capacity before and 3-22 (average 8) months after SVG. Variables from exercise testing were correlated with symptomatic response, left ventricular hemodynamics, and graft patency. Functional capacity (NYHA) improved in 38 (85%), while 27 (59%) had a significant improvement in exercise performance. Functional aerobic impairment (FAI), or the percentage deviation from expected V O O2 max , improved by a mean of 16% ( P < 0.001). Maximal systolic pressure-rate product/100 increased 36 ( P < 0.002). Twenty of 29 (66%) with presurgical S-T segment depression had a normal response after surgery. Thirty-three patients were studied for graft patency and had quantitative angiography. Seventeen had all grafts patent and demonstrated a mean improvement of 21% in FAI ( P < 0.0007). Those with occluded grafts showed no improvement in exercise performance. Sixteen of 22 (73%) with severe exercise impairment showed significant improvement, but only four of 14 (29%) with mild impairment showed a significant improvement. There were no mean changes in left ventricular end-diastolic pressure, cardiac index, contraction plot, or systolic ejection fraction (SEF) in any of the patients. Preoperatively nine had a depressed SEF ( Maximal treadmill testing has demonstrated objectively that SVG can improve functional capacity and that it is correlated with graft patency. Ideal surgical candidates appear to be those with severe exercise impairment and unimpaired ventricular performance.

A volumetric microrespirometer was used to investigate chages in the tissue respiration of the adrenals, thyroid and pituitary of rats after a single exhausting physical exercise. The animals were made to run on a treadmill for 90 min, that is, until they showed signs of fatigue. Oxygen uptake increased in the adrenals hy 39.1% but decreased in the thyroid by 51.9% and in the pituitary by 37.4%. It should be emphasized that the changes were statistically highly significant. The authors suppose that increased adrenal O2 uptake may have been due to the stimulating influence of ACTH on the respiration processes in the cortex and intensification of oxidative processes in the medulla, and also increased blood supply in the entire organ during physical work. Diminished consumption of oxygen by the thyroid may have been caused by the inhibitory influence of factors connected with stress (the inhibitory influence of ACTH and corticosteroids, effort sympathicotonia, and increased body temperature). The decreased respiration of the pituitary is difficult to interpret but may have been caused by diminished blood supply and perhaps also an overheating of the organism.

A submaximal cardiovascular step test was developed to be used with men between the ages of 18 and 60 years. A test-retest reliability coefficient of .94 was obtained. Test results correlated with the Balke Treadmill Test resulted in a validity coefficient of .94. Metabolic requirements range from VO2 of 1.55 to 2.44 liters.

Background: Although post-menopausal obesity is an important public national health problem in Saudi Arabia, to date no study has evaluated the effects of weight reduction on biochemical & clinical parameters and quality of Life for obese Saudi post-menopausal women. Objective: The aim of this study was examine the effects of aerobic versus resisted exercise training effects upon systemic inflammation biomarkers and quality of life for obese post-menopausal Saudi women. Material and Methods: One hundred Saudi post-menopausal obese women participated in this study, their age ranged from 50-58 years and their body mass index (BMI) ranged from 30-35 kg/m2. All participants were divided into two equal groups: The first group received aerobic exercise training on treadmill where, the second group received resisted exercise training. Health-related quality of life (SF-36 HRQL), tumor necrosis factor– alpha(TNF-α), Interleukin-2(IL-2), Interleukin-4 (IL-4), Interleukin-6 (IL-6) and C-reactive protein (CRP) were measured before and after 3 months at the end of the study. Results: The mean values of SF-36 HRQL subscale scores were significantly increased, while the mean value of TNF-α, Il-2, IL-4, IL-6,CRP and BMI were significantly decreased in both groups after treatments. There were significant differences between mean levels of the investigated parameters in group (A) and group (B) after treatment with more changes in patients received aerobic exercise training. Conclusion: The current study provides evidence that aerobic exercise is more appropriate than resisted exercise training in modulating inflammatory cytokines and quality of life among obese post-menopausal women.Keywords: Aerobic exercise; resisted exercises; inflammatory cytokine; quality of life; obesity; menopause.

Three human subjects exercised at 2 and 4 mph on a treadmill while breathing room air and 100% oxygen. Respiratory frequency was voluntarily controlled at 6, 12, and 24 breaths/min so that the only ventilatory response possible was a change in tidal volume. Mean CO2 tension of arterialized venous blood was maintained constant near the resting value by each subject under all experimental conditions, including oxygen breathing with the exception of one subject who hyperventilated at 2 mph while breathing 24 times/min. Oscillations in alveolar and arterial Pco2 within each respiratory cycle were markedly altered by respiratory frequency and the intensity of exercise. No relationship was found between Ve, Va, Vt, and the amplitude of oscillation or the rate of change of arterial Pco2 or Po2. Varying levels of the work of breathing were observed while the arterial Pco2 remained constant. It is concluded that the oscillations in arterial Pco2 and Po2 which are observed at rest and during muscular exercise are associated phenomena, not controlling stimuli. oscillations; chemoreceptors; work of breathing; control of ventilation; frequency of breathing Submitted on June 17, 1964

Twenty patients with the late systolic murmur-non-ejection click syndrome were exercised on a treadmill with continuous monitoring of the ECG. Eight patients exhibited ectopic activity at rest; exercise increased the abnormalities in 16 during or after exercise. Ventricular ectopic beats were frequent during exercise in 7 patients, atrial fibrillation occurred in 1, while flat ST segment depression of 1 mm. or more developed in 12 of the patients. These changes associated with exercise may indicate a cardiomyopathy associated with the prolapsed valve leaflet which may be linked with the occurrence of sudden death reported in this syndrome. Exercise stress appears to unmask myocardial irritability and should be considered in all patients presenting with this syndrome. Therapy may then be prescribed for those patients developing significant arrhythmias or conduction changes.

The effects of breathing high concentrations of oxygen on treadmill performance time, the exercise and postexercise pulse, and the relationship between excess lactic acid and oxygen debt were studied. The breathing of oxygen during the maximal performance test improved the performance time of each test. Oxygen debt was significantly reduced for the first minute of recovery after breathing oxygen during the test. The excess lactic acid was reduced after the first minute of recovery and was found to peak during the third minute of recovery. A linear relationship was observed between excess lactic acid and oxygen debt while breathing air or oxygen during the test.

The ventilatory response to exercise was studied on awake dogs trained to run on a treadmill. Various combinations of speed and grade produced metabolic increases up to 6.5 times the resting value. Ventilatory flow, tidal volume and respiratory frequency were measured cycle by cycle for the purpose of analyzing the roles of nervous and humoral stimuli in ventilatory control. In light work, neurogenic stimuli play an important role in ventilatory control and are responsible for almost all the increase in ventilation. Some minutes after the beginning of exercise a delayed humoral stimulation comes into play. Thermal polypnea develops progressively; its intensity depends on the metabolic level. The respiratory centers are organised in such a way that the dog provides for both its metabolic and thermolytic needs. Thus, in light exercise performed at 19 °C ambiant temperature, PaO2, PaCO2 and arterial pH are not modified by thermal panting. Thermal polypnea induces no relative alveolar hyperventilation unless the work load is high or the environment does not allow an important heat loss.

A refined, reliable thrombin generation test with good sensitivity for both hypo- and hypercoagulability is described. When serial thrombin generation curves were obtained in cardiac patients subjected to standardized treadmill stress, fluctuations of the clotting system were observed in some and a marked tendency to hypercoagulability in others. The relationship of in vitro hypercoagulability as reflected by thrombin generation to an increased tendency to thrombosis remains to be determined.

Summary. An apparatus is described allowing photographic recording of absolute arterial pressures and rapid pressure variations in dogs even during movement. Aortic pressure curves from normal animals are compared with those obtained shortly after narcosis and operation. Two experiments are presented in which the pressures were recorded during light muscular work and in the transition from work to rest. The author wishes to thank F. BUCHTHAL, M. D., for advice and encouragement in the course of this work.

A double-blind study of the effects of isosorbide dinitrate, 10 mg given orally four times a day, propranolol, 40 mg four times a day, and the combination of these two drugs was performed on 21 patients with angina pectoris. Each patient received placebo, isosorbide, propranolol, and the combination of the two drugs for 1 month each in a random sequence over 4 months. The number of anginal pains and nitroglycerin tablets used were recorded, and a multistage treadmill ECG exercise test was performed after each treatment period. Frequency of anginal pains was reduced significantly with propranolol (7.0±2.5 pains/week) and the combination of propranolol and isosorbide dinitrate (9.9±2.9) as compared with placebo (21.0±6.4). Similarly, the number of nitroglycerin tablets was reduced with propranolol-containing regimens. Isosorbide was not significantly better than the placebo. Symptomatic improvement with propranolol could be related to a reduction in heart rate, and the product of heart rate and systolic blood pressure during exercise ( P