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PubMed1979

Effects of exercise on plasma and liver lipids of rats. IV. Effects of exercise on hepatic cholesterogenesis and fecal steroid excretion in rats.

The effects of treadmill exercise on hepatic cholesterogenesis and fecal steroid excretion were studied using male Wistar rats fed a commercial pellet ration. Exercise, in comparison with ad libitum or pair-feeding sedentary groups, caused the following significant changes: (i) a reduction in the concentration of plasma triglyceride, phospholipid and cholesterol; (ii) a reduction in liver weight; (iii) increases in hepatic 3-hydroxy-3-methylglutaryl-CoA reductase activity and incorporation of mevalonate into digitonin precipitable sterol; (iv) increases in excretion of neutral and acidic steroids into the feces; (v) the increase in lipoprotein lipase activity in the cardiac muscle, and (vi) the decrease in the concentration of carcass triglyceride but not of cholesterol. These data suggest that the mechanism responsible for the plasma cholesterol-lowering effect of exercise is attributable to an increase in exretion of fecal neutral and acidic steroids accompanied by an acceleration of cholesterol turnover in the body.

Animals↗

PubMed1999

Metallothionein induction in rat liver by dietary restriction or exercise and reduction of exercise-induced hepatic lipid peroxidation.

Metallothioneins (MTs) occur throughout the animal kingdom and they are induced in vivo by metals, hormones, cytotoxic agents, and some kind of stress. It is well known that various stresses such as starvation and immobilization can induce MT synthesis in animal tissues, but the influence of dietary restriction is unknown. The MT levels in the liver increased by food-deprivation and then decreased by refeeding, and a long period of starvation down-alters hepatic MT levels. When the stress is intensified, the induced quantity of hepatic MT is reduced. It became clear that hepatic MT concentrations are controlled within a two fold limit when stressed by dietary restriction. MT was also induced in rat liver at recovery stage following an exhaustive running exercise, and thionein was synthesized first and then zinc bound to the protein. The half-life of hepatic MT induced by exercise (which is a nonmetallic inducer) was estimated at 5.2 h. Preinduced MT markedly suppressed exercise-induced lipid peroxidation in rat liver.

Animals↗

PubMed2002

Pre-exercise anxiety and the anxiolytic responses to acute bouts of self-selected and prescribed intensity resistance exercise.

BACKGROUND: The present investigation examined the state anxiety responses to acute bouts of self selected and prescribed intensity resistance exercise (RE). College age women (n=19) currently enrolled in a beginning weight training class were recruited to participate. METHODS: Participants completed 3 randomly assigned, counterbalanced conditions of self-selected intensity RE, prescribed intensity RE (75% of 1RM), and quiet rest control. Assessments of state anxiety (SA) were obtained prior to as well as 5, 20, 60, and 120 min following each condition. Ratings of perceived exertion (RPE) were assessed within both RE conditions. RESULTS: RPE was found to be higher during prescribed intensity RE. To examine the role of pre-exercise anxiety level on SA responses, baseline values in each condition were stratified into high and low groups. Analyses revealed that, irrespective of intensity, SA was significantly reduced following both self-selected and prescribed RE conditions within the high baseline SA group. Conversely, reductions in SA only emerged 60 and 120 min following the selfselected RE condition in the low baseline SA group. CONCLUSIONS: It is concluded that the SA responses to acute RE are influenced by baseline anxiety level and the relative intensity of the bout. Results suggest that reductions in SA are observed following acute RE independent of the intensity of exercise in the presence of high baseline SA values whereas reductions are only exhibited following less intense bouts of RE when low baseline SA levels are evident.

Adult↗

PubMed1986

Post-exercise anaemia as a result of exercise overloading of the organism.

The aim of the present study was to determine the relation between the exercise load used in training and the changes in the basic parameters of the erythrocytic system. The experiments were carried out on 33 Wistar rats (females and males). The animals were forced to run at a velocity of 1.47 km/h inside an electrically-driven rotating drum. The experiments were performed for 35 days. In the 1st - (females) and 2nd - (males) group the exercise period was prolonged by 1 min per day on successive days, and by 2 min per day in the 3rd - (females) and 4th - (males) group. Prior to and after the training period the haemoglobin concentration, haematocrit, erythrocyte and reticulocyte counts were determined in the venous blood. Reticulocytes were divided into four age groups and the percentage each particular age group was calculated. All the trained groups manifested a decrease in haemoglobin concentration, hematocrit values and erythrocyte count and a concomitant elevation of the reticulocyte count with a shift towards youngest forms was found. Rats of the 3rd and 4th groups developed post-exercise anaemia.

Anemia↗

PubMed1984

The effect of starvation on the gastro-entero-pancreatic hormonal and metabolic responses to exercise. (GEP hormones in starvation and exercise).

Gastro-entero-pancreatic hormonal and metabolic responses to bicycle ergometer exercise for one hour following twelve hours fasting (P1) and 36 hours fasting (P2) were compared. During P1 plasma secretin and blood glycerol increased. Pre-exercise concentrations of plasma C-terminal glucagon-like-immunoreactivity (C-GLI), secretin, blood glycerol, 3-hydroxybutyrate and lactate were higher after 36 hours fasting than 12 hours fasting. During P2 glycerol rose sharply while secretin, C-GLI and 3-hydroxybutyrate remained higher than during P1. A role for secretin and C-GLI in accelerated lipolysis during fasting and exercise is possible.

3-Hydroxybutyric Acid↗

PubMed1980

The treatment of exercise-inducible chronic stable angina with diltiazem. Effect on treadmill exercise.

Although diltiazem has been shown to alleviate vasospastic angina pectoris, its effect on exercise-inducible chronic stable angina has not been objectively studied. Accordingly, the effect of diltiazem was studied in this condition with a placebo controlled double-blind randomized cross-over protocol at three dose levels (120, 180 and 240 mg/day) during graded treadmill exercise. Three end-points were evaluated: 1) time to onset of angina or fatigue if angina were eliminated; 2) time to 1 mm ST segment depression or fatigue if ST depression were eliminated; and 3) time to termination of exercise (2+ angina or fatigue). All end-points were prolonged at all dose levels. At the highest dose of 240 mg/day, time to onset angina or termination was prolonged from a placebo time of 8.0 +/ 0.9 to 9.8 +/- 0.9 minutes (p = < .001); time to ST depression or termination was prolonged from 7.8 +/- 0.9 to 9.1 +/- 0.8 minutes (p = .007); and time to termination was prolonged from 9.9 +/- 0.9 to 10.8 +/- 0.8 minutes (p = .02).

Aged↗

PubMed1993

Vitamin D status and hypocalcemic response to protamine in exercised and non-exercised dairy cows.

Bone resorption was studied in post parturient cows using intravenous injection of protamine. Protamine inhibits bone resorption and the protamine-induced hypocalcemia can be taken as a measure of this process. The studies were performed in a herd where half of the cows had been tied indoors for 2 1/2 years, the other half had been given daily exercise during the same period. All animals were fed in the same way. The hypocalcemic response to protamine was the same in both groups, which indicates that exercise did not change bone resorption. The serum levels of calcium, inorganic phosphorus and magnesium around parturition did not differ. The daily exposure to daylight increased the serum level of 25-(OH)-cholecalciferol in late summer in the exercised group.

Animals↗

PubMed1999

Change point in VCO2 during incremental exercise test: a new method for assessment of human exercise tolerance.

The main purpose of this study was to present a new method to determine the level of power output (PO) at which VCO2 during incremental exercise test (IT) begins to rise non-linearly in relation to power output (PO) - the change point in VCO2 (CP-VCO2). Twenty-two healthy non-smoking men (mean +/- SD: age 22.0 +/- 0.9 years; body mass 74.5 +/- 7.5 kg; height 181 +/- 7 cm; VO2max 3.753 +/- 0.335 l min-1) performed an IT on a cycloergometer. The IT started at a PO of 30 W, followed by gradual increases of 30 W every 3 min. Antecubital venous blood samples were taken at the end of each step and analysed for plasma lactate concentration [La]pl, blood PO2, PCO2 [HCO3-]b and [H+]b. In the detection of the change-point VCO2 (CP-VCO2), a two-phase model was assumed for the 'third-minute-data' of each step of the test. In the first phase, a linear relationship between VCO2 and PO was assumed, whereas in the second, an additional increase in VCO2 was allowed, above the values expected from the linear model. The PO at which the first phase ends is called the change point in VCO2. The identification of the model consists of two steps: testing for the existence of the change point, and estimating its location. Both procedures are based on suitably normalized recursive residuals (see Zoladz et al. 1998a. Eur J Appl Physiol 78, 369-377). In the case of each of our subjects it was possible to detect the CP-VCO2 and the CP-VO2 as described in our model. The PO at the CP-VCO2 amounted to 134 +/- 42 W. The CP- VO2 was detected at 136 +/- 32 W, whereas the PO at the LT amounted to 128 +/- 30 W and corresponded to 49 +/- 11, 49 +/- 8 and 47 +/- 8.6% VO2max, respectively, for the CP-VCO2, CP-VO2 and the LT. The [La]pl at the CP-VCO2 (2.65 +/- 0.76 mmol L-1), at the CP-VO2 (2.53 +/- 0. 56 mmol L-1) and at the LT (2.25 +/- 0.49 mmol L-1) were already significantly higher (P < 0.01, Students t-test) than the value reached at rest (1.86 +/- 0.43 mmol L-1). Our study illustrates that the CP-VCO2 and the CP-VO2 occur at a very similar power output as the LT. We therefore postulate that the CP-VCO2 and the CP-VO2 be applied as an additional criterion to assess human exercise tolerance.

Adult↗

PubMed1998

An upper body exercise system incorporating resistive exercise and neuromuscular electrical stimulation (NMS).

A device is described which combines arm crank ergometry and neuromuscular electrical stimulation (NMS) delivered at different phases of the crank cycle. Details of the device including circuit schematics are shown. The device was evaluated by non-paralyzed subjects for its operational safety and by tetraplegic subjects for its effectiveness as a muscle-strengthening tool. All subjects showed improvement in one or more of their manual muscle scores. The most dramatic increased motor score occurred in the triceps muscle group. There was an average increase in the manual muscle score of 1.1 +/- 0.2 for the left triceps and 0.7 +/- 0.1 for the right triceps after eight weeks of NMS assisted exercise. No adverse effects were experienced and it appears to meet safety considerations necessary for this group of individuals. Preliminary observations indicate that an eight-week exercise protocol that utilizes this device can be beneficial for this population.

Adolescent↗

PubMed1995

Comparison of Nottingham Health Profile (NHP) scores with exercise duration and measures of ischaemia during treadmill exercise testing in patients with coronary artery disease.

A cross-sectional study of patients with stable coronary artery disease was performed to compare perceived health status with the results of a treadmill exercise test. One hundred and twenty one patients, mean age 55.07 years, 106 male, who had all suffered a myocardial infarction under the age of 56 years, up to 9 years earlier were studied. Perceived health status was assessed using the Nottingham Health Profile, part 1 of which assesses six dimensions of normal living, and part 2 seven areas of daily life. Nottingham Health Profile scores were higher (worse perceived health status) in patients with poor treadmill exercise capacity within all dimensions of part 1 (energy, pain, physical mobility P < 0.001, emotional reactions, sleep P < 0.01, social isolation P < 0.05) and most of those within part 2 (care of home, taking holidays P < 0.001, hobbies P < 0.01, relationships at home, sex life P < 0.05). The perceived health status of patients without a history of angina is significantly better than those with angina (pain, physical mobility P < 0.001, energy, emotional reactions, social isolation P < 0.01, sleep P < 0.05, within part 1, taking holidays P < 0.01, care of the home, social life, sex life, hobbies P < 0.05, within part 2). Thus, patients with a poor perceived health status, also have poorer results using more conventional clinical measures of coronary artery disease. The Nottingham Health Profile may be a useful adjunct in patient assessment.

Activities of Daily Living↗

PubMed1995

Effects of caffeine ingestion on exercise-induced changes during high-intensity, intermittent exercise.

In this study a double-blind design was used to determine the effect of caffeine on time to exhaustion and on associated metabolic and circulatory measures. Eight male subjects ingested either caffeine (5 mg/kg body weight) or a placebo 1 hr prior to exercise at 85-90% of maximum workload. Subjects were encouraged to complete three 30-min intermittent cycling periods at 70 rpm with 5 min rest between each. The exercise was terminated when the subject failed to complete three 30-min periods or failed to maintain 70 rpm for at least 15 s consecutively. Serum free fatty acids, glycerol, blood glucose, lactate, perceived exertion, heart rate, and O2 cost were measured. The time to exhaustion was significantly longer during the caffeine trial than during the placebo trial. Serum free fatty acid levels were significantly different between trials. The decline in blood glucose levels was significantly less during the caffeine trial than during the placebo trial. There were no significant differences between trials for the other measures. It was concluded that caffeine increases time to exhaustion when trained subjects cycled intermittently at high levels of intensity.

Adult↗

PubMed1989

Exercise responses during incremental and high intensity and low intensity steady state exercise in patients with obstructive lung disease and normal control subjects.

A study was undertaken to compare the cardiac and ventilatory responses to different types of exercise between 12 patients with COPD and ten normal age-matched control subjects. Both groups attained comparable heart rates and the percentage of their maximum predicted heart rate. Patients had a higher heart rate and VE with a lower O2P at every level of work load. Patients had a mean VT which approximated their FEV1 and increased their VE predominantly by increasing their respiratory frequency. During the low intensity test, despite the differences in work load, the patients had comparable heart rates and VE. No resting spirometric value accurately predicted work load, VE, or maximal VO2. We conclude that patients have a reduced work tolerance that is not adequately explained by their reduced lung function. Thus, cardiac factors, deconditioning, and the dyspneic sensation may be determinants of exercise limitation in some patients.

Exercise↗

PubMed1991

Individualized aerobic and high intensity training for asthmatic children in an exercise readaptation program. Is training always helpful for better adaptation to exercise?

In order to define the role of individualized training intensity in a conditioning program for asthmatic children, we have trained seven asthmatics (age = 11.4 +/- 1.8 years) at their ventilatory threshold (VTh) intensity level for a three-month period (aerobic training) and at maximal intensity also for three months (high intensity training). VTh is the point at which a nonlinear increase of VE occurs. Another group of seven asthmatics (age = 11.4 +/- 1.5) served as control subjects. Cardiopulmonary fitness was determined on a cycle ergometer before and after each training session. This study demonstrated that aerobic training, correctly adapted to the child's physical ability, induces the following: (1) a rapid and marked cardiovascular fitness increase; and (2) a decrease in VE over a given work range so that VTh is increased. This is of great importance because hyperventilation is a major determinant of exercise-induced bronchospasm. In contrast, even if high intensity training is well tolerated in an indoor swimming pool, the long-term effects are unsuitable for asthmatic children because the decrease of VTh will involve an increase of hyperventilation, even when exercise is performed at submaximal intensity.

Adaptation, Physiological↗

PubMed2005

[Cardiopulmonary exercise testing: the exercise stress test of the future?].

Scientific evidence is mounting that cardiopulmonary exercise testing (CPET) offers different potential clinical applications in cardiology. In comparison with traditional ECG stress testing, CPET provides more accurate diagnostic information and prognostic insights as well, in particular in patients with chronic heart failure and primary pulmonary hypertension. The barriers that actually limit the diffusion of CPET among cardiologists are primarily "cultural", because modern ergospirometric tools are easy to use, and the time required for a CPET is not dissimilar from that of a standard ECG stress test. At present, time seems to be ripe for considering CPET as the new exercise stress test in cardiology.

Electrocardiography↗

PubMed1988

The use of isometric exercise as a means of evaluating the parasympathetic contribution to the tachycardia induced by dynamic exercise in normal man.

Fourteen normal subjects were submitted to isometric exercise (IE), dynamic exercise (DE) and a combination of the two (IE + DE). The main purpose of the present study was to use IE as a means of evaluating the mechanism of the heart rate (HR) increase induced by DE. To this end, the magnitude of the IE (handgrip) was standardized so as to cause an elevation of HR almost exclusively by vagal withdrawal: IE was performed using a dynamometer strain-gauge system with a linear response at 75% of maximum voluntary contraction (MVC) for 10 s, repeated at 1 min intervals. The change in HR evoked by IE under control conditions was compared with that evoked during DE, and during the corresponding recovery period. DE was performed by the legs, with the subject in the seated position for 4 min, at workloads of 55 and 105 watts, separated by a rest period. In the combined protocol, IE was performed at the beginning of DE, as well as at 1, 2 and 3 min during DE, and at 0, 1, 2, 3 and 5 min during recovery period. The following results were obtained: (1) IE associated with DE always induced smaller increase in heart rate than IE alone, and this effect was more marked at 105 than at 55 W; this finding suggested a workload-dependent vagal withdrawal at the very beginning of DE that was sustained until the end of effort.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1996

Does weight-bearing exercise protect against the effects of exercise-induced oligomenorrhea on bone density?

Does weight-bearing exercise offset bone loss associated with oligomenorrhea? If so, bone mineral density (BMD) will be stable at weight bearing sites but decrease at non-weight-bearing sites with increasing duration of oligomenorrhea. To test this hypothesis, BMD (g/cm2), was measured by dual-energy X-ray absorptiometry in 41 oligomenorrheic ballet dancers aged 17.7 +/- 0.2 years (mean +/- SEM) and 46 age-matched controls with normal menstrual function. BMD correlated negatively with the duration of oligomenorrhea at weight-bearing and non-weight-bearing sites (femoral neck, r = -0.33, p < 0.05; Ward's triangle, r = -0.29, p = 0.06; trochanter, r = -0.33, p < 0.05; lumber spine, r = -0.25, p = 0.1; skull, r = -0.29, p = 0.06; arms, r = -0.32, p < 0.05; ribs, r = -0.30, p = 0.06). The slopes of the regression of BMD on duration of oligomenorrhea were greater at the proximal femur (trochanter, -0.28 +/- 0.13, femoral neck, -0.24 +/- 0.11; Ward's triangle, -0.29 +/- 0.15) than the skull (-0.15 +/- 0.08, p < 0.05, p < 0.1, p < 0.1 respectively). The slopes at the trochanter and femoral neck were also greater than at the ribs (-0.10 +/- 0.05; both p < 0.1). In the dancers with oligomenorrhea of less than 40 months duration, BMD was higher than the age-predicted mean at weight-bearing sites (except the lumber spine), but not at non-weight-bearing sites (femoral neck, 9.1 +/- 3.4%; Ward's triangle, 10.0 +/- 1.7%; trochanter, 9.4 +/- 4.1%, all p < 0.05; lumbar spine, -2.1 +/- 2.7%, NS; skull, -2.5 +/- 2.1%, NS; ribs, -3.0 +/- 1.6% NS; arms, -3.9 +/- 1.6%; p < 0.05). In the dancers with greater than 40 months oligomenorrhea, BMD was no higher than the age predicted mean, at the weight bearing sites, and was lower at non-weight bearing sites (femoral neck, 4.3 +/- 2.3%, NS; Ward's triangle, 3.5 +/- 3.2%, NS; trochanter, 2.1 +/- 2.7%, NS; lumbar spine, -3.8 +/- 2.1%, NS; arms, -7.5 +/- 0.8%, p < 0.05; skull, -6.2 +/- 1.8%, p < 0.01; ribs, -5.4 +/- 1.1%, p < 0.0001). In conclusion, weight-bearing exercise is unlikely to offset the deleterious effects of oligomenorrhea. Bone loss appears to occur at all sites but may begin from a higher level at weight-bearing sites and may proceed more rapidly.

Absorptiometry, Photon↗

PubMed1991

Predictability of psychic outcome for exercise training and exercise training including relaxation therapy after myocardial infarction.

Predictability of the psychic outcome for two cardiac rehabilitation programmes was investigated in 119 myocardial infarction patients. They were randomly assigned to either a five-week daily exercise training or to an identical training in combination with six sessions of relaxation therapy, individually. The psychic outcome was constructed as a composite measure of change on six psychological questionnaires. The aim was to determine the predictive qualities of base-line: (1) clinical data; (2) exercise testing; (3) psychosocial information derived from interview; and (4) validated psychological questionnaires and whether the kind of rehabilitation programme has any influence on the predictive qualities of the variables. The psychic outcome turned out to be highly predictable (multiple correlation of 0.72). Predictors of relatively high importance were age, work-status and job-level, followed by mild heart failure, diastolic blood pressure and heart rate, all of them dependent upon the kind of treatment. It implies that the type of rehabilitation programme modified the effect of the determinants of psychic outcome. This research strategy is promising and deserves to be stimulated in order to build rehabilitation programmes tailored to the needs and abilities of the individual patient.

Adaptation, Psychological↗

PubMed2004

Comparison of the predictive value of exercise-induced ST depression versus exercise technetium-99m sestamibi single-photon emission computed tomographic imaging for detection of coronary artery disease in patients with left ventricular hypertrophy.

Scant knowledge exists regarding the significance of either additional ST depression in the presence of baseline depression or new stress-induced ST depression in patients with left ventricular (LV) hypertrophy. Accordingly, the purpose of this investigation is to determine whether the appearance and/or severity of ST abnormalities during exercise stress testing can accurately predict the prevalence of ischemic burden as measured by quantitative technetium-99m-sestamibi single-photon emission computed tomographic imaging in patients with LV hypertrophy. The results show that the presence of exercise ST-segment depression, as well as its magnitude, are not accurate predictors for identifying patients with coronary artery disease in the presence of electrocardiographic criteria for LV hypertrophy.

Adult↗