Bicycle Ergometer Work Research Articles

Specificity of aerobic and anaerobic work capacities and powers.

Thirty-three untrained subjects of both sexes, 18-31 years of age, performed several tests on cycle ergometers. Maximal aerobic power (MAP) was obtained in a progressive work test. Maximal aerobic capacity (MAC) was measured in a 90-min maximal test and was computed as the total work output during that period. Two all-out cycle ergometer work tests lasting 10 s and 90 s were used to estimate the anaerobic alactic capacity (AAC) and lactic capacity (ALC). Anaerobic alactic power (AAP) was computed as the highest output in 1 s in the AAC test and anaerobic lactic power (ALP) was obtained as the mean output during the last 5 s in an all-out test of 30 s. Correlation coefficients were computed between all measurements of capacity and power expressed per kg of body weight as well as with scores adjusted for sex differences. Common variances (r2 X 100) between measurements of power were either low (MAP-AAP, 40%) or moderate (MAP-ALP, 61%; AAP-ALP, 62%) while common variances between measurements of capacity were sometimes low (MAC-AAC, 49%) or higher (MAC-ALC, 76%; AAC-ALC, 77%). The common variances between tests of power and capacity reached high values when calculated with metabolic criteria of the same class (MAP-MAC, 81%; AAP-AAC, 92%). These results provide quantitative evidence to support the notion of specificity between the aerobic and the anaerobic work performances and support the distinction between capacity and power of the three energy systems.

The increase of perceived exertion, aches and pain in the legs, heart rate and blood lactate during exercise on a bicycle ergometer.

This study was designed to show the general increase in perceived exertion, perception of aches or pain in the legs, heart rate (HR), and blood lactate, and the covariance between these variables during bicycle ergometer work, and to describe individual differences both within and between power levels by testing a large group (28 male students). Estimates of perceived exertion and feelings of aches or pain in the legs were recorded using Borg's category-ratio scale (CR-10). The subjects were tested with a stepwise increase of power levels with 40 W increments up to a voluntary maximum. Though HR increases fairly linearly with power, the other variables follow positively accelerating functions with exponents of about 1.6-2 for the perceptual variables, and an exponent of about 3 for blood lactate. The results from the 8 most fit subjects could be described in the same way as for the whole group except for blood lactate, where there was a need to include a threshold value (b), that, together with a rest value (a), shows the starting point of the function (R = a + c(W - Wo)n). The data support the idea that a combination of heart rate and blood lactate is a better predictor of perceived exertion and feelings of aches and pain in the legs, than is each of the single physiological variables taken alone.

Historical remarks on the development of the aerobic-anaerobic threshold up to 1966.

During the years 1957 to 1963, we introduced the concept of the onset of anaerobic metabolism to measure cardiopulmonary and peripheral aerobic performance capacity. On the basis of bicycle and crank ergometer work with load increments of 3 min duration, we described a point at which the pulmonary ventilation (VE) increases at a greater rate than O2 uptake (VO2). Because the changes of the arterial blood lactate (Laa) and VE coincide we defined this point as the "point of the optimal ventilatory efficiency," identical with the "O2 endurance performance limit," later called "anaerobic threshold" by Wasserman et al.

A study on RPE during bicycle ergometer work and physical education class

The purpose of this study was to examine the applicability of Borg's rating scale. Heart rate (HR), oxygen uptake (Vo2) and rating of perceived exertion (RPE) were measured during two differ ent forms, bicycle ergometer work at 300kpm, 450kpm and 600kpm and physical education class of exercise. The subjects of this study were 7 healthy schoolboys in the eighth grade, aged 13.7 to 14.6 years and Vo2 max predicted 33.7 to 70.4ml×kg-1×min--1The results were as follows:1. Correlation coefficient of HR and %Vo2 max with RPE were 0.820 (p<0.01) and 0.892 (p<0.01), respectively, during the bicycle ergometer work.2. Correlation coefficient of HR and RPE was 0.589 (p<0.01) during physical education class.3. RPE response followed a linear increase as a function of HR or %Vo2 max during the two forms of exercise.Differences were found in the level of RPE in relation to HR during the two forms of exercise. It seems that the differences were related to complexity of exercise.

Force Kinetics and Oxygen Consumption During Bicycle Ergometer Work in Racing Cyclists and Reference-Group

The forces acting on the right crank of a bicycle ergometer were measured in 18 male subjects (6 racing cyclists, 8 students of physical education, 4 long distance runners) during an incremental exercise test. Oxygen consumption (\(\dot V_{O_2 } \)) was simultaneously determined by means of a breath-by-breath method.

Marginal malnutrition and reduced physical work capacity of migrant adolescent boys in Southern Brazil

We measured the effect of marginal malnutrition on physical work capacity of adolescent children of agricultural migrant workers in Southern Brazil. Nutritional status was evaluated using 24-h dietary recall. Body size was evaluated anthropometrically. Biochemical assessments were also made. Physical work capacity (PWC170) was assessed by measuring heart rate, blood lactic acid levels, and oxygen consumption during submaximal bicycle ergometer work. The same tests were also carried out on a comparable group of local well-to-do boys of the same age in the same community who served as controls. The dietary results suggest that adolescent boys of migrant families were marginally malnourished. Their physical growth and development were retarded by at least 1 yr. They had significantly lower reserves of body fat and less muscle mass when compared with controls.Their Hb levels were normal. At the submaximal work loads measured (0, 25, 50, 75 W) the migrant children exhibited similar oxygen consumption and gross exercise efficiency as the control children, but achieved this work at a higher percentage of their maximum work capacity as shown by significantly higher heart rates for the same oxygen consumption. Higher blood lactic acid levels in the migrant children suggest that the available muscle mass was under greater stress to accomplish the same task. PWC170 was reduced one-third in the migrant children (migrant 643 ± 162 kpm/min, control 905 ± 345 kpm/min; p < 0.005). These differences were largely associated with weight (migrant 20.6 ± 5.9 kpm/kg/min; control 18.8 ± 4.3 kpm/kg/min; p > 0.1). These observations suggest that marginal as well as severe malnutrition affect physical work capacity at levels low enough to affect growth and development.

Effect of pedal rate, brake load and power on metabolic responses to bicycle ergometer work.

Abstract In earlier investigations of the energy cost of bicycle ergometer work, pedal rate and brake load have been varied simultaneously while maintaining a constant power, thus confounding the effects of these factors. A two-way factorial design was used to isolate the effects of rate and load upon metabolic responses during ergometer work while also determining any interaction of effects (a power effect). Nine men performed bicycle ergometer tests at five pedal rates (20-100 r.p.m.) with five brake loads at each rate (0-4 kp). Steady-state V˙O2 was found to be a quadratic function of pedal rate when brake load was held constant, and to be a quadratic function of brake load when pedal rate was held constant. There was a significant interaction between the effects of rate and load which resulted in a shifting of the most efficient rate-load combination as the power changed. Significant differences (10-29%) were found between rate-load combinations at a constant power. It was concluded that the energy cost of bicycle ergometer work is not linearly related to the work output, but rather depends on the rate and force with which the work is accomplished.

Combined Effects of Metabolic Heat Production and High AmbientTemperature on Rectal Temperature during Work and at Rest

Eight healthy male Japanese were exposed to different heat stress, i.e., metabolic heai production during work, high ambient temperature and both of them. After resting on a chair for 30 min. at 28°C with 50% R.H., subjects were examined for 61 min. at following conditions: bicycle ergometer work at 28°C with 50% R.H., rest on a chair at 45°C with 50% R.H. and bicycle ergometer work at 45°C with 50% R.H.. The work load of bicycle ergometer was 450 kgrn/min, and the pedalling frequency was kept at 50 rpm. At the condition of work at 45°C, exposure was stopped due to rise in rectal temperature to 39.0°C, subjective impossibility to continue the work and objective observation. All of the eight subjects could not complete the work for 61 min. at 45°C because of some of the criteria descrived above. The mean value of duration of work at 45°C was 39.4 min.. At the end of the resting period at 28°C, rectal and skin temperature measurements and expired gas collection for 3 min. were made. During exposure period, rectal and skin temperature were measured at every 2 and I min., respectively. Expired gas was collected at 8-11, 28-31 and 58-61 min, during exposure period. The sites of skin temperature measurement were chest. upper arm, thigh and leg. Oxygen uptake was used to calculate the heat production. Body heat content was calculated by rectal temperature and skin temperature, and heat dissipation by heat production and increase in body heat content. During work at 45°C, rectal temperature rised rapidly and there was remarkable heat storage because high ambient temperature disturbed heat dissipation from body to environment. During work at 28°C, there was no significant heat storage though rectal temperature rised. At rest at 45°C, rectal temperature rised due to heat invation from environment to body, and there was significant heat storage.

Metabolic and Cardiovascular Responses at Rest and during Submaximal Work in the Cold environment

The metabolic and cardiovascular responses of 5 male students, 21-24 years of age, were studied at rest and during submaximal work when they were exposed to ambient temperatures of 6°C and 26°C with relative humidity 50%. On entering the experimental condition, each subject was seated on the bicycle ergometer for 40-41 min rest period, and then performed 8-9 min bout of bicycle ergometer work with pedaling frequency 50 r.p.m., at loads of 300, 600 and 900 kgm/min. Metabolic and cardiovascular parameters were observed during the last 3 -4 min of each rest and work period. In the condition of 6°C, at rest and 300, 600 kgm/min, oxygen uptake, cardiac output and stroke volume increased when compared with the values observed at 26°C. However, at 900 kgml min, no difference was found between 6°C and 26°C. On the other hand, when these cardiovascu-lar parameters were plotted against oxygen uptake, no difference between 6°C and 26°C was found in cardiac output and arterio-venous oxygen difference. However, at the same values of oxygen uptake within the range up to 2.0 l/min, stroke volume at 6°C was 20-30 ml/beat larger and heart rate at 6°C was 15-20 beats/min smaller than the values seen at 26°C.

Cardiorespiratory adaptations to exercise in cystic fibrosis.

We compared the cardiorespiratory adaptations to exercise of 21 patients with cystic fibrosis (CF) with those of 17 age-, height-, and weight-matched subjects without lung disease. To assess differences in adaptations to exercise in patients with varying severities of pulmonary disease, we grouped them on the basis of their lung function tests results. Exercise consisted of a progressive, incremental cycle ergometer work test. Work load increased every 2 min until the subject could not continue. During exercise, heart rate, and end-tidal and mixed expired O2 and CO2 tensions, minute ventilation (VE), arterial oxygen saturation, and blood pressure were monitored. The patients breathed significantly larger volumes than normal subjects at work loads greater than 0.8 W/kg. Patients with mild, moderate, or seven disease ventilated more per unit of oxygen consumption than did patients with normal pulmonary functions or control subjects. Despite this high total VE, alveolar hypoventilation was observed in the severe groups, as evidenced by elevated end-tidal PCO2, and contributed to aterial desaturation. Resting heart rate was higher in the severe group. The rate of changes in heart rate with increasing work load was the same in all groups. We conclude that the increased VE during exercise was an attempt to maintain alveolar ventilation in the face of increased dead space. The elevated VE was adequate to preserve normal gas exchange in all patients except those with severe lung disease, where CO2 retention and arterial desaturation were observed.

The effects of negative air ions on various physiological functions during work in a hot environment.

The effects of negative air-ions on human physical performance has been investigated. Twenty-one healthy males, 20–25 years old (X=23.6±2.6) were exposed to two 180-min rest and exercise sessions two weeks apart. The subjects were randomly assigned into either an experimental group (n=12) or to a control group (n=9). The experimental group performed the first session in neutral air conditions and the second one in air containing 1.36 to 1.90×105 negative air ions and 1.40 to 1.66×102 positive air ions/ml. The control group performed both sessions under neutral air conditions. All sessions were held at Ta=40±1‡C and 25±5% RH. Each session included one hour of resting under the respective ionization conditions, followed by 3 30-min cycle ergometer work bouts, separated by 7-min rest periods. The mechanical work-load during the bicycle exercise was 1.64±0.6 W/kg BW. The experimental group showed a significant reduction with negative air-ions in heart rate (HR), in rectal temperature, and in the rating of perceived exertion (RPE), all when compared with their own neutral session. The control group showed no significant changes between the first and the second exposure. Although not statistically significant, being exposed to negative air-ions seems also to reduce total sweat rate and minute ventilation (VE), and to increase O2 pulse. It is suggested that under the conditions of this study negative air ions canimprove various cardiovascular and thermoregulatory functions as well as subjective feelings during physical effort. It is felt that such positive influences may be augmented by increasing the exposure time to negative ionized air and/or prolonging the stressful conditions.

Anaerobic and aerobic responses of males and females to rope skipping.

Six male and six female subjects performed maximal bicycle ergometer work and skipped rope at selected rates. Measures included oxygen uptake (VO2), oxygen debt (VO2 debt), blood lactate, and heart rate (HR). Mean values for males for the maximum test and while skipping at 120, 140, and 160 turns . min-1 were, respectively: VO2-50.2, 38.3, 39.7, and 44.3 ml . kg-1 . min-1; HR-185, 166, 168, and 178 beats . min-1; VO2 debt--5.70, 3.65, 3.50, and 4.04 liter; and lactate--12.7, 7.4, 7.6, and 9.2 mM . 1(-1). For females: VO2--42.8, 39.8, 39.4, and 39.4 ml . kg-1 . min-1; HR--185, 181, 181, and 181 beats . min-1; VO2 debt--4.71, 4.27, 4.22, and 4.15 liter; and lactate--11.5, 11.5, 12.2, and 11.9 mM . l-1. No significant differences were found between treatments for females for any measure. Rope skipping placed high demands on both aerobic (females, 92% VO2max, males, 76-88%) and anaerobic capacities (females, 100-106% lactate values after maximum bicycle exercise; males, 58-72%). In males, who did not reach VO2max during rope skipping, it was verified that the VO2 requirement does not increase with skipping rate over a relatively wide range, but that extremely high rates do require more energy from both aerobic and anaerobic sources. Differences in tolerance of males and females to rope skipping were attributed to the lower aerobic power and higher body fat of females.

Physical work capacity of firemen. With special reference to demands during fire fighting.

During work in hot environments with a self-contained compressed air line breathing apparatus (SCCALBA) firemen perform physically arduous work and are exposed to severe heat loading. In view of the overloading risk involved, firemen should receive regular medical checkups with exercise tests and electrocardiography (ECG). Four hundred and seventeen firemen from 20 to 59 a of age in the Stockholm Fire Service performed exercise tests, including ECG, at intensities of 100, 150 and 200 W. The calculated maximal aerobic power declined with increasing age. Forty-seven firemen (11 0/0) were unable to complete the exercise test. Thirty of these men were in the oldest age group (50-59 a), of which 34 % failed to complete the test. The test was usually stopped prematurely because of physical exhaustion, but ECG changes, high blood pressure, and joint pain were also common causes of interruptions in the oldest age group. On the basis of the above results and earlier measurements during simulated fire fighting in a SCCALBA, recommendations on the future examinations of the physical work capacity of firemen are discussed. Thus, a fireman should be capable of performing bicycle ergometer work for 6 min at an intensity of 200 W. In order to allow for the age-induced decline in physical work capacity, a prospective fireman should be able to perform exercise at 250 W in the preemployment examination. It is suggested that exercise tests with ECG recordings should be performed every fifth year up to the age of 40 and every other year thereafter. Moreover, no fireman over the age of 50 should be allowed to perform fire fighting in a SCCALBA. Efficient physical training at least twice a week should be a part of every fireman`s regular duties.

Thermal comfort during work

Different methods of quantifying thermal alliesthesia were used to examine the circadian variations of thermal comfort. At eight different times of the 24 h day, four subjects were exposed to a constant room temperature of 25°C. After 30 min rest, the subjects performed 50 W bicycle ergometer work for 45 min. A 5 s temperature stimulus of 15°, 20°, 25°, 30°, 35°, and 38°C was applied on the hand, forehead, and back of the neck. For each stimulus the subjects voted their degree of thermal comfort on the subjective thermal comfort scale, ranging from +2 for very pleasant to −2 for very unpleasant. The most pleasant temperature on the back of the neck was chosen by voluntary control. This procedure was performed at the start and repeated every 15 min throughout the exposure time. A 5:5 × 2.7 cm2 Peltier thermode was used to give the temperature stimuli. Voluntary control voting was carried out using the temperature control knob without looking at the temperature scale of the thermode.

Responses of exercising subjects to acute “passive” cigarette smoke exposure

Responses to 2 hr of “passive” cigarette smoke exposure have been tested in 23 healthy young men and women who were performing intermittent bicycle ergometer work sufficient to increase respiratory minute volumes by a factor of 2.5. A simple crossover design compared data with reactions to sham exposures of similar duration. Cigarettes were smoked by a standard machine; chamber carbon monoxide concentrations were 20 (moderate dose) or 31 ppm (heavy exposure). Symptoms were much as in moderate exposures without exercise. The main complaints were of odor and eye irritation. Cough, nasal discharge or stuffiness, and throat irritation were also reported, but wheezing, shortness of breath, and tightness in the chest were both uncommon and unsupported by objective evidence of bronchospasm. A small increase of tidal volume and respiratory minute volume seemed due to anxiety rather than airway irritation. Static lung volumes were unchanged, but there were small (3–4%) decreases of FVC, FEV 1.0', V ̇ max 50% , and V ̇ max 25% . The changes of dynamic lung volumes were of the order anticipated from the “cigarette equivalent” encountered by the passive smoker ( < 1 2 cigarette in 2 hr).

Reliability of noninvlasive methods for measuring cardiac function in exercise.

Externally recorded systolic time intervals (STI's), indirect (CO2 re-breathing) cardiac output, and auscultatory blood pressures were measured during upright bicycle ergometer work in 20 healthy men, aged 24-56 yr. The subjects were studied on 2 separate days at steady-state work loads chosen to represent light (mean heart rate (HR) = 96 beats.min-1), moderate (HR = 118 beats.min-1) and heavy (HR = 147 beats.min-1) exercise. In addition to determinations of cardiac output, systolic time intervals, and blood pressure, the individual's mean systolic ejection rate (stroke volume/left ventricular ejection time) was calculated as a measure of left ventricular function. In general, heart-rate-corrected STI's were found to be reliable and reproducible. Reliability coefficients for total electromechanical systole and left ventricular ejection time ranged from 0.93 to 0.96 while those for the preejection period and its subcomponents were between 0.63 and 0.88. The reliability of cardiac output, stroke volume, mean systolic ejection rate, and systolic blood pressure was also considered to be acceptable but tended to be higher during moderate and heavy work (r = 0.85-0.95) compared to light exercise (r = 0.60-0.83).

Studies on the Physiological Load of Cycling

To estimate the value of physiological load of cycling with special reference to cardiorespiratory responses, oxygen intake, pulmonary ventilation and heart rate was measured directly during seven kinds of bicycle ergometer work in the laboratory, and heart rate during outdoor cycling were also obtained by the telemetry method for seven healthy young males of ages from 19 to 21 years.physiological load was expressed by % of maximal oxygen intake (% of Vo2 max.). Maximal oxygen intake was directly measured by the Daglas Bag method, and oxygen intake levels were estimated indirectly from heart rate levels during cycling using the regression equations determined for each individual between directly measured oxygen intake and heart rate. Outdoor cycling was made under the following conditions: (a) Twenty-one kinds of conditions which consisted of 5, 10, 15, 20, 25, 30 and 35 km per hour of cycling speed and 1, 67 (40×24), 2.35 (40×17), 3.13 (50×16) gear ratios of pedaling. (b) Long distance cycling tour of about 120 km as a prolonged exercise.Results obtained were as follows: (1) High significant correlation was obtained between oxygen intake and heart rate for each subject. (2) When cycling speed was increased to 15 km per hour on level ground, physiological load gradually reached the level of 30%Vo2 max. However, when increased to 30 or 35 km, it was indicated abrupt increase at 80 or 900 level, (3) There was significant different of physiological load among gear ratio of pedaling, (4) In the case of long distance cycling tour, heart rate was changed from 94 to 164 beats per minutes, so that predicted levels of physiological load was between 45 to 75% of Vo2 max.

Perceived exertion and stimulus intensity modulation.

Perceptual augmentation and reduction were considered contrasting styles of Stimulus Intensity Modulation. Differences in perceived exertion between augmenters and reducers were determined for three cycle ergometer work loads. Subjects were 20 males having similar physiological characteristics. Stimulus Intensity Modulation was determined by kinesthetic figural aftereffect. Augmenters rated their perceptions of physical exertion to be more intense than reducers at 450, 750 and 1050 kpm/min. Differences in physiological responses between augmenters and reducers were not significant at the three work loads. Style of Stimulus Intensity Modulation appeared differentially to influence perceived exertion at the work levels studied.

Perception of exertion in the elderly, effects of aging, mode of exercise and physical training.

Ratings of perceived exertion by the Borg psychophysical scale have been made on 26 men and 30 women aged 60 to 70 yr. All were volercise lines relating the ratings of exertion to heart rate were closely similar in men and women, scores at all heart rates being 2 or 3 units higher than in young adults. A brief progressive exercise protocol on the treadmill yielded somewhat lower ratings than bicycle ergometer work, the discrepancy being marked in women. At any given oxygen intake, ratings were higher for females than malesy nd higher for old than young subjects. However, when oxygen intake was expressed as a percentage of the directly measured maximum oxygen intake, scores became independent of sex and age. A 35-wk. period of conditioning substantially reduced heart rates but had little effect on the perception of effort at a given work load. This unexpected result may reflect a closer approximation of core and skin temperatures with reduction of sub-cutaneous fat.

Urinary excretion of free noradrenaline and adrenaline in trained and untrained men.

Measurements of free noradrenaline and adrenaline were made in the urine of 28 men sampled after rest and exercise prior to, and following six and twelve weeks of an excercise programme. The training consisted of thirty minutes of running and walking four times per week at an intensity estimated at 75% of the age-predicted maximum heart rate. A fifteen minute standardized cycle ergometer work test was conducted on all subjects prior to the training and following six and twelve weeks of training. Noradrenaline and adrenaline excretions in the urine were measured before and after the work test.