Metabolic and cardiopulmonary responses to wheelchair and bicycle ergometry

1979 ◽  
Vol 46 (6) ◽  
pp. 1066-1070 ◽  
Author(s):  
R. M. Glaser ◽  
M. N. Sawka ◽  
L. L. Laubach ◽  
A. G. Suryaprasad
Keyword(s):  
Heart Rate ◽  
Oxygen Uptake ◽  
Power Output ◽  
Respiratory Exchange Ratio ◽  
Pulmonary Ventilation ◽  
Mechanical Efficiency ◽  
Bicycle Ergometer ◽  
Upper Body ◽  
Bicycle Ergometry ◽  
Ventilatory Equivalent

To evaluate wheelchair activity in reference to a more familiar mode of locomotion, metabolic and cardiopulmonary responses to wheelchair ergometer (WERG) and bicycle ergometer (BERG) exercise were compared. Eighteen able-bodies subjects were tested on a combination wheelchair-bicycle ergometer. Oxygen uptake (VO2), respiratory exchange ratio (R), pulmonary ventilation (VE), ventilatory equivalent (VE/VO2), percent net mechanical efficiency (ME), and heart rate (HR) were determined at power output (PO) levels of 30, 90, and 150 kpm/min on each ergometer. For WERG and BERG exercise, VO2, VE, and HR increased linearly with PO. Generally, VO2, R, VE, VE/VO2, and HR responses were higher (P less than 0.05) during WERG than BERG exercise at each PO. Blood lactate was determined after 150 kpm/min, and found to be higher (P less than 0.05) during WERG than BERG exercise. ME increased with PO and was lower (P less than 0.05) for WERG than BERG exercise at each PO level. The greater metabolic and cardiopulmonary responses observed during WERG exercise may be due to inefficient biomechanics and the relatively small upper body musculature used for propulsion.

Relative Stresses of Wheelchair Activityl

1980 ◽  
Vol 22 (2) ◽  
pp. 177-181 ◽  
Author(s):  
Roger M. Glaser ◽  
Stephen A. Barr ◽  
Lloyd L. Laubach ◽  
Michael N. Sawka ◽  
Agaramg G. Suryaprasad
Keyword(s):  
Heart Rate ◽  
Oxygen Uptake ◽  
Respiratory Exchange Ratio ◽  
Pulmonary Ventilation ◽  
Bicycle Ergometer ◽  
Acute Exposure ◽  
Bicycle Exercise ◽  
Rest Periods ◽  
Ventilatory Equivalent

To study relative stresses of wheelchair activity, seven able-bodied subjects' metabolic (oxygen uptake) and cardiopulmonary (heart rate and pulmonary ventilation) responses were determined during wheelchair (arm stroking) and bicycle (leg pedaling) exercise at identical propulsion velocities and work rates. For this, subjects exercised on a combination wheelchair-bicycle ergometer at wheel velocities of 1.17, 2.34, and 3.51 km/hr. The six bouts of exercise were intennittent~5-min exercise periods interspersed by 10-min rest periods. At 1.17 km/hr, no significant differences were found between wheelchair and bicycle exercise for each of the monitored variables. At 2.34 and 3.51 km/hr, however, all responses were significantly higher for wheelchair exercise. At these higher velocities, calculated respiratory exchange ratio and ventilatory equivalent values were also significantly higher for wheelchair exercise. These results suggest that acute exposure to wheelchair activity could be relatively stressful and could limit rehabilitative efforts.

Plateau in Oxygen Uptake at Maximal Exercise in Male Children

1996 ◽  
Vol 8 (1) ◽  
pp. 77-86 ◽  
Author(s):  
Glen E. Duncan ◽  
Anthony D. Mahon ◽  
Cheryl A. Howe ◽  
Pedro Del Corral
Keyword(s):  
Heart Rate ◽  
Oxygen Uptake ◽  
Respiratory Exchange Ratio ◽  
Maximal Exercise ◽  
Treadmill Exercise ◽  
Pulmonary Ventilation ◽  
Anaerobic Capacity ◽  
Test Duration ◽  
Run Time ◽  
Aerobic And Anaerobic

This study examined the influence of test duration and anaerobic capacity on VO2max and the occurrence of a VO2 plateau during treadmill exercise in 25 boys (10.4 ± 0.8 years). Protocols with 1-min (P1) and 2-min (P2) stages, but identical speed and grade changes, were used to manipulate test duration. On separate days, VO2max was measured on P1 and P2, and 200-m run time was assessed. At maximal exercise, VO2, heart rate (HR), and pulmonary ventilation (VE) were similar between protocols, however, respiratory exchange ratio (RER) and treadmill elevation were higher (p < .05) on P1 than on P2. Plateau achievement was not significantly different. On P1, there were no differences between plateau achievers and nonachievers. On P2, test duration and 200-m run time were superior (p < .05), and relative VO2max tended to be higher (p < .10) in plateau achievers. Indices of aerobic and anaerobic capacity may influence plateau achievement on long, but not short duration tests.

Oxygen uptake during the first minutes of heavy muscular exercise

1961 ◽  
Vol 16 (6) ◽  
pp. 971-976 ◽  
Author(s):  
Per-Olof &Aring;strand ◽  
Bengt Saltin
Keyword(s):  
Heart Rate ◽  
Lactic Acid ◽  
Oxygen Uptake ◽  
Aerobic Capacity ◽  
Pulmonary Ventilation ◽  
Peak Oxygen Uptake ◽  
Bicycle Ergometer ◽  
Muscular Exercise ◽  
Work Time ◽  
Submaximal Work

Oxygen uptake, heart rate, pulmonary ventilation, and blood lactic acid were studied in five subjects performing maximal work on a bicycle ergometer. After a 10-min warming up period work loads were varied so that exhaustion terminated exercise after about 2—8 min. Peak oxygen uptake and heart rate were practically identical (sd 3.1% and 3 beats/minute, respectively) in the experiments. The heavier the work was and the shorter the work time the higher became the pulmonary ventilation. There was a more rapid increase in the functions studied when the heaviest work loads were performed. It is concluded that aerobic capacity can be measured in a work test of from a few up to about 8 min duration, severity of work determining the actual work time necessary. Duration of work in studies of circulation and respiration during submaximal work should exceed 5 min. Submitted on June 23, 1961

A Systematic Review of Submaximal Cycle Tests to Predict, Monitor, and Optimize Cycling Performance

2016 ◽  
Vol 11 (6) ◽  
pp. 707-714 ◽  
Author(s):  
Benoit Capostagno ◽  
Michael I. Lambert ◽  
Robert P. Lamberts
Keyword(s):  
Heart Rate ◽  
Power Output ◽  
Perceived Exertion ◽  
Heart Rate Recovery ◽  
Mechanical Efficiency ◽  
Cycling Performance ◽  
Rating Of Perceived Exertion ◽  
Time To Exhaustion ◽  
Gross Mechanical Efficiency ◽  
Multiple Variables

Finding the optimal balance between high training loads and recovery is a constant challenge for cyclists and their coaches. Monitoring improvements in performance and levels of fatigue is recommended to correctly adjust training to ensure optimal adaptation. However, many performance tests require a maximal or exhaustive effort, which reduces their real-world application. The purpose of this review was to investigate the development and use of submaximal cycling tests that can be used to predict and monitor cycling performance and training status. Twelve studies met the inclusion criteria, and 3 separate submaximal cycling tests were identified from within those 12. Submaximal variables including gross mechanical efficiency, oxygen uptake (VO2), heart rate, lactate, predicted time to exhaustion (pTE), rating of perceived exertion (RPE), power output, and heart-rate recovery (HRR) were the components of the 3 tests. pTE, submaximal power output, RPE, and HRR appear to have the most value for monitoring improvements in performance and indicate a state of fatigue. This literature review shows that several submaximal cycle tests have been developed over the last decade with the aim to predict, monitor, and optimize cycling performance. To be able to conduct a submaximal test on a regular basis, the test needs to be short in duration and as noninvasive as possible. In addition, a test should capture multiple variables and use multivariate analyses to interpret the submaximal outcomes correctly and alter training prescription if needed.

Comparison of maximal oxygen uptake values determined by predicted and actual methods

1965 ◽  
Vol 20 (3) ◽  
pp. 509-513 ◽  
Author(s):  
R. G. Glassford ◽  
G. H. Y. Baycroft ◽  
A. W. Sedgwick ◽  
R. B. J. Macnab
Keyword(s):  
Heart Rate ◽  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Correlation Coefficients ◽  
Bicycle Ergometer ◽  
Exercise Heart Rate ◽  
Indirect Test ◽  
Physical Fitness Test ◽  
Mean Values ◽  
Fitness Test

Twenty-four male subjects aged 17–33 were given three direct tests of maximal oxygen uptake and one indirect test. The direct tests were those of Mitchell, Sproule, and Chapman (treadmill); Taylor, Buskirk, and Henschel (treadmill); and Åstrand (bicycle ergometer). The indirect test was the Åstrand-Ryhming nomogram (bicycle ergometer) employing heart rate response to submaximal work. In addition, the Johnson, Brouha, and Darling physical fitness test was administered. The two treadmill tests and the indirect test yielded significantly higher mean values than did the direct bicycle test. However no other significant differences in mean values occurred. Correlation coefficients between the various oxygen uptake tests as well as the fitness test were all found to be significant (.62–.83), i.e., greater than zero. No correlation obtained proved to be significantly greater than any other. The results indicate that direct treadmill tests, employing greater muscle mass, yield higher maximal oxygen uptake values (8%) than does the direct bicycle ergometer test. The Åstrand-Ryhming nomogram appears to produce a good estimation of maximal oxygen uptake, in a population unaccustomed to cycling. erobic capacity; exercise; heart rate Submitted on September 17, 1964

Determination of maximal aerobic power during upper-body exercise

1983 ◽  
Vol 54 (1) ◽  
pp. 113-117 ◽  
Author(s):  
M. N. Sawka ◽  
M. E. Foley ◽  
N. A. Pimental ◽  
M. M. Toner ◽  
K. B. Pandolf
Keyword(s):  
Heart Rate ◽  
Aerobic Power ◽  
Pulmonary Ventilation ◽  
Maximal Aerobic Power ◽  
Upper Body ◽  
Maximal Heart Rate ◽  
Upper Body Exercise ◽  
Peak Vo2 ◽  
Power Peak

The purpose of this investigation was to evaluate four protocols for their effectiveness in eliciting maximal aerobic power (peak VO2) during arm-crank exercise. Comparisons were made 1) between a continuous (CON) and an intermittent (INT) protocol (both employed a crank rate of 50 rpm) and 2) among the CON protocols employing crank rates of 30, 50, or 70 rpm. For the first group of experiments no significant (P greater than 0.05) differences were found between the CON and INT protocols for peak VO2, maximal pulmonary ventilation (VEmax), maximal heart rate (HRmax), or maximal blood lactate (LAmax) responses. For the second group of experiments, the CON-50 was compared with the CON-30 and CON-70 protocols. In comparison to the CON-50, significantly higher peak VO2 (+10%) and VEmax (+14%) responses were elicited by the CON-70 protocol, whereas significantly lower peak VO2 (-11%), VEmax (-23%), HRmax (-8%), and LAmax (-29%) responses were elicited by the CON-30 protocol. Of the arm-crank protocols examined the combination of a continuous design and a crank rate of 70 rpm provided the most effective protocol to elicit peak VO2 values.

Mechanics of the respiratory system in the newborn tammar wallaby

2002 ◽  
Vol 205 (4) ◽  
pp. 533-538 ◽  
Author(s):  
P. M. MacFarlane ◽  
P. B. Frappell ◽  
J. P. Mortola
Keyword(s):  
Respiratory System ◽  
Spontaneous Breathing ◽  
Minute Ventilation ◽  
Pulmonary Ventilation ◽  
Age Groups ◽  
Mechanical Efficiency ◽  
Tammar Wallaby ◽  
Ventilatory Equivalent ◽  
Rate Of Oxygen Consumption ◽  
Respiratory System Resistance

SUMMARY We investigated whether the mechanical properties of the respiratory system represent a major constraint to spontaneous breathing in the newborn tammar wallaby Macropus eugenii, which is born after a very short gestation (approximately 28 days, birth mass approximately 380 mg). The rate of oxygen consumption (V̇O2) through the skin was approximately 33 % of the total V̇O2 at day 1 and approximately 14 % at day 6. The mass-specific resting minute ventilation (V̇e) and the ventilatory equivalent (V̇e/V̇O2) were approximately the same at the two ages, with a breathing pattern significantly deeper and slower at day 1. The mass-specific compliance of the respiratory system (Crs) did not differ significantly between the two age groups and was close to the values predicted from measurements in eutherian newborns. Mass-specific respiratory system resistance (Rrs) at day 1 was higher than at day 6, and also higher than in eutherian newborns. Chest distortion, quantified as the degree of abdominal motion during spontaneous breathing compared with that required to inflate the lungs passively, at day 1 was very large, whereas it was modest at day 6. We conclude that, in the tammar wallaby at birth, the high resistance of the respiratory system and the distortion of the chest wall greatly reduce the mechanical efficiency of breathing. At this age, gas exchange through the skin is therefore an important complement to pulmonary ventilation.

Training Prescription Guided by Heart-Rate Variability in Cycling

2019 ◽  
Vol 14 (1) ◽  
pp. 23-32 ◽  
Author(s):  
Alejandro Javaloyes ◽  
Jose Manuel Sarabia ◽  
Robert Patrick Lamberts ◽  
Manuel Moya-Ramon
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Oxygen Uptake ◽  
Power Output ◽  
Maximal Oxygen Uptake ◽  
Peak Power ◽  
Performance Enhancement ◽  
Time Trial ◽  
Peak Power Output ◽  
Road Cycling

Purpose: Road cycling is a sport with extreme physiological demands. Therefore, there is a need to find new strategies to improve performance. Heart-rate variability (HRV) has been suggested as an effective alternative for prescribing training load against predefined training programs. The purpose of this study was to examine the effect of training prescription based on HRV in road cycling performance. Methods: Seventeen well-trained cyclists participated in this study. After an initial evaluation week, cyclists performed 4 baseline weeks of standardized training to establish their resting HRV. Then, cyclists were divided into 2 groups, an HRV-guided group and a traditional periodization group, and they carried out 8 training weeks. Cyclists performed 2 evaluation weeks, after and before a training week. During the evaluation weeks, cyclists performed a graded exercise test to assess maximal oxygen uptake, peak power output, and ventilatory thresholds with their corresponding power output (VT1, VT2, WVT1, and WVT2, respectively) and a 40-min simulated time trial. Results: The HRV-guided group improved peak power output (5.1% [4.5%]; P = .024), WVT2 (13.9% [8.8%]; P = .004), and 40-min all-out time trial (7.3% [4.5%]; P = .005). Maximal oxygen uptake and WVT1 remained similar. The traditional periodization group did not improve significantly after the training week. There were no differences between groups. However, magnitude-based inference analysis showed likely beneficial and possibly beneficial effects for the HRV-guided group instead of the traditional periodization group in 40-min all-out time trial and peak power output, respectively. Conclusion: Daily training prescription based on HRV could result in a better performance enhancement than a traditional periodization in well-trained cyclists.

Metabolic, cardiovascular, and respiratory factors in the development of fatigue in lifting tasks

1978 ◽  
Vol 45 (1) ◽  
pp. 64-68 ◽  
Author(s):  
J. S. Petrofsky ◽  
A. R. Lind
Keyword(s):  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Work Load ◽  
Specific Weight ◽  
Bicycle Ergometer ◽  
Isometric Contractions ◽  
Bicycle Ergometry ◽  
Physiological Capacity ◽  
Male Subjects ◽  
Extended Work

Three well-trained male subjects served as volunteers in these experiments to examine the physiological capacity for extended work during lifting tasks. The maximal oxygen uptake (VO2max) during lifting was always lower than work on the bicycle ergometer. However, the work load during lifting which could be maintained for 1--4 h was 50% of the VO2max for lifting each specific weight of box; the limit for lifting light boxes without fatigue was at an oxygen uptake of about 25% of the VO2max obtained from bicycle ergometry. Significant fatigue in the forearm muscles was found during prolonged lifting as assessed from the endurance of isometric contractions and from the surface electromyogram (EMG), and was more pronounced as the weight of the box increased.

Cardiorespiratory responses during prolonged exercise

1961 ◽  
Vol 16 (6) ◽  
pp. 997-1000 ◽  
Author(s):  
Ernest D. Michael ◽  
Kenneth E. Hutton ◽  
Steven M. Horvath
Keyword(s):  
Heart Rate ◽  
Oxygen Uptake ◽  
Energy Cost ◽  
Prolonged Exercise ◽  
Bicycle Ergometer ◽  
Maximum Oxygen Uptake ◽  
Healthy Male ◽  
Heart Rates ◽  
Cardiorespiratory Responses ◽  
Male Subjects

Three healthy male subjects 20 years of age were exercised for 2—8 hr riding a bicycle ergometer or walking on a treadmill. Higher heart rates were found with the bicycle rides than with the walking exercises with equivalent oxygen uptakes. The subjects could not work on the bicycle ergometer at oxygen uptakes of 1.8 liters/min for more than 4 hr but could with this uptake walk 8 hr. The results indicated that an 8-hr period of exercise could be completed without undue fatigue whenever the energy cost did not exceed 35% of the maximum oxygen uptake where heart rates, oxygen uptakes, and rectal temperatures remained below 120 beats/min, 1.4 liters/min, and 38 C, respectively. The heart rate appeared to be the important factor for estimating 8-hr work endurance. A rate of 140 beats/min could not be maintained for more than 4 hr or a rate of 160 beats/min for more than 2 hr without extreme fatigue. Submitted on October 26, 1960

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