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PubMed1977

The influence of acetysalicylic acid on changes in platelet function due to physical exertion.

The influence of acetylsalicylic acid (ASA) on alterations of the platelets resulting from physical exertion was studied in 10 healthy volunteers. Before and 2 h after the administration of placebo or 1 g ASA, venous blood samples were taken for platelet counts, thrombelastography (TEG) and tests of ADP- and epinephrine-induced platelet aggregation. The blood in which the 2-h values were determined was sampled at the highest work-load during sub-maximum exercise on a bicycle ergometer (5 min each at 50, 100 and 150 watts). ASA had no effect on the alterations of the platelets due to physical effort: the increase in the first phase of epinephrine-induced aggregation, the elevation of the platelet count and the hypercoagulability demonstrable by TEG still persisted after the administration of ASA. Some effects were noted, however, that are also observed after the administration of ASA at rest: the second phase of epinephrine-induced aggregation was suppressed and disaggregation after induction with ADP was accelerated.

Adult↗
PubMed1983

[Effect of the mother's exertion on the state of fetus].

Homeostatic changes in pregnant women's organism in result of effort - affect the fetus. In human a single effort of mild intensity may result in fetus' changed pulse and rhythm. In animals changes in acid-base equilibrium and fetus metabolism in result of mother's effort were noted. Furthermore, mother's training during pregnancy exerts delayed effects upon certain physiological properties of the cardiac muscle and metabolism of the progeny.

Female↗
PubMed1983

A category-ratio perceived exertion scale: relationship to blood and muscle lactates and heart rate.

The purpose of this investigation was to study the relationship between perceptual ratings from Borg's new category-ratio scale and some physiological variables during exercise. To accomplish this, scale ratings were related to blood and muscle lactate accumulation and heart rates during a progressive, maximal exercise test on the cycle ergometer. Ten physically active males were utilized as subjects; lactate data were recorded on only 7 of the 10 subjects. Three ratings of perceived exertion were made at each stage of the exercise test: leg effort (LE), cardiorespiratory effort (CE), and leg pain (LP). All ratings showed a positively accelerating increase with exercise intensity as did both blood and muscle lactate, while heart rate increased linearly. The exponents of the power functions describing the perceptual variation ranged from 1.63-1.67 compared to 2.2 for blood lactate and 2.7 for muscle lactate. Polynomial analysis revealed a similar quadratic trend for both perceptual and blood lactate data; however, muscle lactate demonstrated a cubic trend. No significant differences were found between CE and LE at 100, 200, and 300 W (P greater than 0.05). Subjects with the highest percentage of slow-twitch muscle fibers (mean ST%=51.14) rated LE and CE significantly lower ( mean of all power outputs, 0-300 W) than those with the lowest ST% (mean=34.52). It is concluded that the ratings from the category-ratio scale correspond very well with glycogenolytic metabolism leading to lactate accumulation during exercise.

Adolescent↗
PubMed1984

[Evaluation of thallium-201 distribution in myocardial scintigraphies performed after exertion].

Various techniques are described for the electronic processing of myocardial scintigraphic images using 201Thallium taken at various intervals after muscular exertion. The techniques serve to improve image definition and contrast, making them more representative of the physiopathological reality. The advantages and limitations of certain computer techniques for the measurement of radioactive distribution in the left ventricular myocardium are also discussed. Using such techniques it is possible to obtain an objective and comparative assessment of successive images.

Computers↗
PubMed1983

[Relation between the duration of exertion and levels of serum testosterone].

The serum testosterone levels have been shown to be increased following middle- and long distance competitions (up to 42,195 km). The hormone serum levels have been now studied in 63 runners before and after a 107 km race and in an ultramarathon runner before, during and after a 6 hours race. After the 107 km race the mean hormone levels have been found to be reduced from 9,72 to 7,45 ng/ml for the age class 20-29 years; from 6,57 to 4,69 ng/ml for the group 30-39; from 6,22 to 5,13 ng/ml for the group 40-49 years; from 7,56 to 5,46 ng/ml for the age class 50-59. In the ultramarathon runner the testosterone levels sharply rose at the beginning of the training session (from the 7,20 ng/ml to 11,50 ng/ml after 20' training), and subsequently decrease after 3 hours (9,20 ng/ml) and at the end of the 6 hours training (4,60 ng/ml). Based on these and on previous findings the Authors hypothesize that a prolonged exertion produces an initial stimulation of the hormone producing system, followed by its functional exhaustion.

Adult↗
PubMed1982

Acid-base and electrolyte alterations in horses with exertional rhabdomyolysis.

In examination of the acid-base and electrolyte status of 7 horses with acute exertional rhabdomyolysis, the most consistent abnormality was hypochloremia. Metabolic acidosis was not evident in any of the horses. Therefore, the use of sodium bicarbonate in treatment of such disorders may not be indicated in all cases.

Acid-Base Imbalance↗
PubMed1982

Perceived exertion and anaerobic threshold during the menstrual cycle.

Six adult females with normal menstrual cycles (28-31 d in length) volunteered to exercise on a bicycle ergometer on five different days of their menstrual cycles (days 2, 8, 14, 20, and 26; day 1 = onset of menstruation). Each day the subjects exercised at a maximum work load (184.4 W) and at four submaximal exercise intensities (45.0, 83.1, 121.4 and 154.4 W). Ratings of perceived exertion (RPE) were obtained during minute 4 of each 5-min submaximal exercise bout and at exhaustion each day. Overall, RPE was linearly correlated with heart rate (r = 0.87) when all exercise intensities and cycle days were considered. There was no statistically significant (P greater than 0.05) change in RPE at any exercise intensity related to cycle day. Factors (expired ventilatory volume, respiratory frequency, tidal volume, end-tidal CO2 tension, and heart rate) that may have affected RPE, maximal aerobic power, and anaerobic threshold (AT) were also statistically unchanged because of cycle day. Anaerobic threshold averaged 68.7% of the VO2max, or 1.592 l . min for all cycle days, as determined by the total expiratory volume/oxygen uptake "break point" method of Wasserman and co-workers (18). These data support the utilization of female subjects with normal menstrual cycles in psychophysiological studies without regard to menstrual cycle phase.

Anaerobiosis↗
PubMed1982

Differentiated ratings of perceived exertion are influenced by high altitude exposure.

Differentiated ratings of perceived exertion (RPE) were obtained from eight low-altitude residents during cycle exercise at sea level (SL) and after acute (less than 2 h) and chronic (18 d) exposure to high altitude (4,300 m; HA). Mean VO2max was 27% lower with acute HA exposure. Subjects cycled for 30 min at an exercise intensity requiring 85% of VO2max. Respiratory exchange measurements and differentiated RPE were obtained at minutes 5, 15 and 25 of exercise, and pre- and post-exercise blood samples were collected. Differentiated RPE included a local muscular rating, a central or cardiopulmonary ratings, and an overall rating. Despite reduced absolute exercise intensity during acute HA exercise, local RPE were unchanged from SL values. Chronic HA exercise, however, was associated with a significant reduction in local RPE. Blood lactate accumulation during SL exercise was not significantly greater than central ratings, while neither differed significantly from the overall ratings. None of the differentiated ratings differed significantly during acute and chronic HA exercise; central RPE were highest of the ratings during chronic HA exercise. The ventilatory equivalent for oxygen during HA exercise (both acute and chronic) was significantly higher than at SL. This apparent rearrangement in the relative order of magnitude of these three differentiated ratings suggests an alteration in the relationship between perceptual cues sensed as effort.

Adult↗
PubMed1982

Psychophysical bases of perceived exertion.

There is a great demand for perceptual effort ratings in order to better understand man at work. Such ratings are important complements to behavioral and physiological measurements of physical performance and work capacity. This is true for both theoretical analysis and application in medicine, human factors, and sports. Perceptual estimates, obtained by psychophysical ratio-scaling methods, are valid when describing general perceptual variation, but category methods are more useful in several applied situations when differences between individuals are described. A presentation is made of ratio-scaling methods, category methods, especially the Borg Scale for ratings of perceived exertion, and a new method that combines the category method with ratio properties. Some of the advantages and disadvantages of the different methods are discussed in both theoretical-psychophysical and psychophysiological frames of reference.

Heart Rate↗
PubMed1981

[Cardiorespiratory function in young bronchitis patients, mostly mineworkers, before and after kinesitherapy and exertion training. Comparison with a control group (Preliminary results)].

We have studied the effects of respiratory physiotherapy and physical training on the cardiopulmonary function of patients with early chronic bronchitis and broncho-obstruction presumably at the beginning stages. The trained group was compared with a control group who was treated with infra-red rays on the thorax. Both groups were treated during four weeks. All patients were less than 50 years old and all were smokers. They complained of dyspnea on exertion (stage 2 ECCS), cough and expectoration for at least one year. Their spirometry and airway resistance values were normal or near normal but at least two of the following functional indices were altered in all: the He residual volume, the slope of N2 phase III and/or the He bolus phase IV. In the trained group, functional indices of central or peripheral airway obstruction did not change after the four weeks of treatment. On the contrary, the slow vital capacity (SVC) and the peak expiratory flow (PEF), which are presumably more influenced by the force of respiratory muscles, were significantly increased after respiratory rehabilitation. During steady-state exercise of moderate intensity 1.) a slight increase of pH (P less than 0.1 at a VO2 of 1.5 l/min and 1.75 l/min), perhaps due to a lessened lactacidemia, 2.) a decrease in ventilation (VE) (P less than 0.1 at a VO2 of 1.25 l/min) and 3.) a reduction in the alveolo-arterial gradient (AaDO2) (P less than 0.1 at a VO2 of 1.25 l/min) were observed. In the control group there was no change of respiratory functional indices at rest or during exercise after treatment. The reduction of AaDO2 observed in the trained group could be due to an improvement of pulmonary gas exchange. This was small, however, and probably without clinical significance. We believe that the improvement of dyspnea noted in the trained group could be due to the increase in ventilatory performance (SVC, PEF and VE) and to a better O2 extraction in the peripheral muscles.

Adult↗
PubMed1980

[Changes in the hemodynamics of the lung and the right ventricle during rest and exertion in 2 groups of patients with chronic broncho-obstructive syndrome of different severity].

Forty patients with chronic obstructive pulmonary disease (COPD) underwent right heart and central catheterization at rest and during exercise when not in a state of acute exacerbation. They were divided into 2 groups of different functional gravity: group I: FEV1 less than or equal to 1250 ml, RV/TLC greater than or equal to 55% (24 patients); group II: FEV1 > 1250 ml, RV/TLC < 55% (16 patients). At rest, group I had mean pulmonary artery pressure, pulmonary arteriolar resistance, and arterial PCO2 significantly higher, and arterial PO2 significantly lower, than group II. There was no difference in cardiac index, mean atrial pressure and pulmonary wedge pressure between the two groups. During exercise, mean right atrial and pulmonary wedge pressure increased markedly in group I and showed a significant difference from the values of group II. For pooled data of groups I and II, there was a correlation between FEV1 and mean right atrial pressure under exercise and between arterial PO2 and right atrial pressure under exercise. It is concluded that (1) subdividing patients with COPD, as reported here, determines two different blood gases and pulmonary hemodynamic subsets when taken at rest; (2) during exercise, group I patients have "abnormal" right and left ventricular function; (3) FEV1 and arterial PO2 on physical exertion serves to predict mean right atrial pressure under exercise.

Blood Pressure↗
PubMed1995

Ratings of perceived exertion at maximal exercise in children performing different graded exercise test.

The purpose of this study was to examine the rating of perceived exertion (RPE) at maximal exercise in children performing three different graded exercise tests on a treadmill. Eighteen children with a mean +/- SD age of 10.3 +/- 1.4 years volunteered for this study. Each subject performed three different graded exercise test protocols on a treadmill. The protocols consisted of walking only, running only, and combination walk/run. Mean VO2max (ml.kg-1.min-1) during the walking trial (47.3 +/- 5.0) was significantly (p < 0.05) less than during the running (52.1 +/- 4.9) and combination trials (51.9 +/- 5.1). Mean HRmax (bpm) was significantly (p < 0.05) lower during the walking test (195.2 +/- 7.9) compared to the running (202.2 +/- 7.4) and combination tests (202.3 +/- 6.6). Mean RPE at maximal exercise was 18.1 +/- 2.1 in the walking trial, 16.8 +/- 3.0 in the running trial, and 16.8 +/- 2.6 in the combination trial, and was significantly (p < 0.05) greater in the walking trial compared to the other two testing protocols. These data indicate that although VO2max during a walking test is lower, effort sensation is higher compared to protocols that use running as the mode of exercise. The factors involved with RPE selection in this age-group remain to be established.

Child↗
PubMed1995

Prescription of exercise intensity for the obese patient: the relationship between heart rate, VO2 and perceived exertion.

OBJECTIVE: It has been suggested that relative heart rate reserve (% HRR), relative oxygen uptake (% VO2peak), and rating of perceived exertion (RPE) can be used interchangeably to prescribe exercise intensity. The purpose of this study was to examine the relationship between % HRR, % VO2peak, and RPE in obese females prior to and following substantial weight loss. SUBJECTS: 122 obese females (% Body fat = 45.9 +/- 5.0%) who participated in a weight loss intervention program. METHOD: Functional aerobic capacity was measured at baseline and following 12 weeks of exercise training and weight loss using a multi-stage Modified Balke treadmill protocol. The VO2, heart rate (HR), and RPE were measured at each stage, with VO2 and HR data converted to the percentages of the peak levels attained. These multi-stage data were then analyzed using mixed-model regression procedures to examine the relationship between % HRR, % VO2, and RPE. RESULTS: With RPE as the dependent variable, results indicated that % HRR and % VO2, corresponded to RPE values consistent with existing guidelines (70% = 13-14 RPE), and this was true for analyses performed at baseline and following weight loss. Further, baseline results indicated that % HRR and % VO2 corresponded to similar levels of exercise intensity (40-70% HRR = 40-70% VO2peak). However, following weight loss, % HRR represented a higher level of intensity than its corresponding % VO2peak. CONCLUSIONS: The results of this study suggest that RPE can be used as subjective marker of exercise intensity in an obese female population. However, despite adhering to existing guidelines prior to weight loss, there may be a discrepancy in the relationship between % HRR and VO2max following severe weight loss, possibly due to the decrease in resting HR following exercise training and weight loss. These findings directly impact the prescription and monitoring of exercise intensity for obese patients.

Adult↗
PubMed1994

[Unusual triggering circumstance of benign acute cerebral angiopathy; link with exertion cephalalgia?].

Immediately following a scream of fear, a sixty-year old woman complained of severe bilateral headache which relapsed several times over the following month during exercise. There was no history of sympathomimetic drug intake. The work-up was normal save for minimal subarachnoid bleeding and the angiogram showed a disseminated "sausage-string" appearance over all cerebral arterial territories, without aneurysm. The unusual triggering event in this case and the subsequent recurrence of headache in relation to exercise lead us to discuss possible links between the clinical entity of "Isolated benign cerebral angiopathy" and exertional headache.

Cerebral Arteries↗
PubMed1994

Chronic exertional compartment syndrome of the lower leg.

This review focuses on the clinical history, diagnosis, and treatment of chronic exertional compartment syndrome (CECS) of the lower leg. Measurement of muscle compartment pressures, the most conclusive way to confirm the diagnosis, may yield significantly elevated values in CECS patients compared to normal controls. It is important to recognize that medial tibial syndrome is a distinct clinical entity from deep posterior CECS. Once a diagnosis of CECS is established, surgical decompression of the involved compartment is recommended. For as yet unknown reasons, the results of fasciotomy are almost always satisfactory in the anterior compartment and significantly less so in the posterior compartment.

Chronic Disease↗
PubMed1993

The relationship between iron status and perceived exertion in trained and untrained women.

The subjects for this study were 24 female, well-trained distance runners and 41 sedentary, female university students. On the basis of haematological measurements, the subjects were divided into four groups: a group with iron deficiency, non-anemic (normal haemoglobin and red cell count but serum ferritin less than 20 micrograms degrees 1-1) runners (IDR, n = 11), a group of runners with normal iron status (NR, n = 13), a group of sedentary women with normal iron status (NC, n = 26) and a group of iron deficient, non-anemic sedentary subjects (IDC, n = 15). Maximal oxygen uptake (VO2max) and lactate thresholds were determined during incremental bicycle ergometer exercise testing and on separate occasions the ratings of perceived exertion (RPE) were assessed at 25, 50, 75 and 90% VO2max using Borg's scale. There were no differences in the relationship between RPE and work load groups of runners or sedentary subjects with normal and deficient iron status. Iron deficiency did not affect VO2max and lactate thresholds. However, low body iron stores (serum ferritin level below 20 micrograms degrees 1-1) without overt anemia was associated with increased venous blood lactate concentration after maximal exercise load. This study demonstrated that physical work capacity and RPE were not affected by iron deficiency without anemia either in trained or untrained women.

Adult↗
PubMed1994

Perceived exertion during submaximal G exposures before and after physical training.

Ratings of perceived exertion (RPE) were registered at submaximal levels in G endurance tests of a combined strength and endurance training program in 17 pilots. After 12 months of physical training, the endurance G tolerance (time to exhaustion during simulated aerial combat maneuver), increased by a mean of 40% (p < 0.001), while the mean RPE at 5 min submaximal G exposure decreased by 1.2 units (p < 0.02). Following 12 months of physical training, a significant relationship was observed between the improvement of the endurance G tolerance and the decrease of the RPE at 5 min (p = 0.05). Mean SaO2 at 5 min increased from 84 to 90% (p < 0.01) after training, while heart rate responses to G stress did not change. It is concluded that mean RPE and, to some extent, mean SaO2 during submaximal G exposures may be used as indicators of shifts in endurance G tolerance. The procedure may reduce the need for exhaustive G tolerance tests with associated risks and discomfort.

Aerospace Medicine↗