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.

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.

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

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

Heat tolerance of exercising lean and obese prepubertal boys

1975 ◽  
Vol 39 (3) ◽  
pp. 457-461 ◽  
Author(s):  
E. M. Haymes ◽  
R. J. McCormick ◽  
E. R. Buskirk
Keyword(s):  
Heart Rate ◽  
Oxygen Uptake ◽  
Heat Tolerance ◽  
Rectal Temperature ◽  
Sweat Rate ◽  
Rest Periods ◽  
Lower Oxygen ◽  
Prepubertal Boys ◽  
Submaximal Work ◽  
Prepubertal Girls

Seven lean and five obese boys, aged 9–12 yr, exercised in four environments: 21.1, 26.7, 29.4, and 32.2 degrees C Teff. Subjects walked on a treadmill at 4.8 km/h, 5% grade for three 20-min exercise bouts separated by 5-min rest periods. Rectal temperature (Tre), skin temperature (Tsk), heart rate (HR), sweat rate, and oxygen uptake (VO2) were measured periodically throughout the session. Lean boys had lower Tre and HR than obese boys in each of the environments. Increases in Tre were significantly greater for the obese at 26.7 and 29.4 degrees C Teff. No significant differences in Tsk and sweat rate (g-m-2-h-1) were observed between lean and obese boys. Obese boys had significantly lower oxygen consumptions per kg but worked at a significantly higher percentage of VO2max than lean boys when performing submaximal work. Responses of the obese boys to exercise in the heat were similar to those of heavy prepubertal girls studied previously, except that the boys were more tolerant of exercise at 32.2 degrees C Teff than the girls. Lean boys had lower HR than lean girls in each environment, but lower Tre only at 32.2 degrees C Teff.

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

Physiological Responses of Endurance-Trained Male Wheelchair Athletes to a 10-Kilometer Treadmill Time Trial

2002 ◽  
Vol 19 (4) ◽  
pp. 496-508 ◽  
Author(s):  
Ian G. Campbell ◽  
Clyde Williams ◽  
Henryk K.A. Lakomy
Keyword(s):  
Heart Rate ◽  
Oxygen Uptake ◽  
Respiratory Exchange Ratio ◽  
Physiological Responses ◽  
Time Trial ◽  
Peak Oxygen Uptake ◽  
Moderate Correlation ◽  
Wheelchair Athletes ◽  
Dependent Variables ◽  
The Relationship

The purpose was to examine selected physiological responses of endurance-trained male wheelchair athletes in different Paralympic racing classes (T2, n = 3; T3, n = 8; T4, n = 7) during a 10-km treadmill time trial (TM:10-km). Peak oxygen uptake (V̇O2 peak) was determined, and a TM:10-km was completed on a motorized treadmill. From this, % V̇O2peak utilized and the relationship between V̇O2peak and TM:10-km were established. During the TM:10-km, the following dependent variables were examined: propulsion speed, oxygen uptake, respiratory exchange ratio, and heart rate. The results showed athletes utilize a high % V̇O2peak (78.4 –13.6%) during the TM:10-km. There was a moderate correlation (r = -.57, p < .01) between VO2peak and TM:10-km. No physiological differences were found between the paraplegic racing classes (T3, T4), which suggests that there is some justification in amalgamating these racing classes for endurance events.

Conventional Testing Produces Submaximal Values for Oxygen Uptake in Elite Runners

2020 ◽  
pp. 1-6
Author(s):  
Fernando G. Beltrami ◽  
Timothy D. Noakes
Keyword(s):  
Oxygen Uptake ◽  
Exercise Test ◽  
Respiratory Exchange Ratio ◽  
Elite Athletes ◽  
Pulmonary Ventilation ◽  
Running Speed ◽  
Incremental Test ◽  
Exercise Tests ◽  
Sufficient Intensity ◽  
Fixed Order

Purpose: This study aimecd to investigate whether elite athletes could reach higher values of maximal oxygen uptake () during a decremental exercise test in comparison with a traditional incremental test, as recently demonstrated in trained individuals. Methods: Nine male runners (age 25.8 [5.1] y, season best 10-km time 31:19 [1:50]) performed, on different days, 3 maximal uphill (5% grade) running exercise tests in fixed order: an incremental test (INC1), a V-shape exercise test (where speed started at 0.5 km·h−1 higher than the top stage finished during INC1 and was slowly decreased during 5.5 min, when it was again increased in similar fashion to the INC tests), and a final incremental test (INC2). Results: during the V-shape exercise test was higher than during INC1 (6.3% [3.0%], P = .01), although running speed was lower (16.6 [1.7] vs 17.9 [1.6] km·h−1, P = .01). Performance was similar between INC1 and INC2, but during INC2 was higher than INC1 (P < .001). During the V-shape exercise test, 5 participants reached the incremental part of the test, but did not increase (, P = .67), despite higher running speed (approximately 1.1 km·h−1, P < .01). Heart rate, pulmonary ventilation, breathing rate, and respiratory exchange ratio measured at were not different between tests. Conclusion: A decremental exercise test of sufficient intensity can produce higher than a traditional incremental test, even in elite athletes, and this is maintained during a subsequent incremental test.

A 33-yr follow-up of peak oxygen uptake and related variables of former physical education students

1997 ◽  
Vol 82 (6) ◽  
pp. 1844-1852 ◽  
Author(s):  
Per-Olof Åstrand ◽  
Ulf Bergh ◽  
Åsa Kilbom
Keyword(s):  
Heart Rate ◽  
Physical Education ◽  
Oxygen Uptake ◽  
Aerobic Power ◽  
Pulmonary Ventilation ◽  
Peak Oxygen Uptake ◽  
Cycle Ergometer ◽  
Education Students ◽  
Physical Education Students

Åstrand, Per-Olof, Ulf Bergh, and Åsa Kilbom. A 33-yr follow-up of peak oxygen uptake and related variables of former physical education students. J. Appl. Physiol. 82(6): 1844–1852, 1997.—In 1949, 27 female and 26 male physical education students were studied at a mean age of 22 and 25 yr, respectively. They were restudied in 1970 and 1982. Measurements included oxygen uptake, heart rate, and pulmonary ventilation during submaximal and maximal exercise on a cycle ergometer and treadmill. After 21 yr, peak aerobic power was significantly reduced, from 2.90 to 2.18 l/min and from 4.09 to 3.28 l/min for women and men, respectively. After another 12 yr, the 1970 maxima were not reduced further. From 1949 to 1982 there was a decrease in peak heart rate from 196 to 177 beats/min in women and from 190 to 175 beats/min in men ( P < 0.05). Highest pulmonary ventilation did not change significantly. At an oxygen uptake of 1.5 l/min, the heart rate was the same in 1949 as in 1982. In conclusion, the physical fitness level of the subjects was well above average for these ages. From 1970 to 1982 there was no decline in the average peak aerobic power, a finding possibly related to increased habitual physical activity.

Metabolic and circulatory responses to wheelchair and arm crank exercise

1980 ◽  
Vol 49 (5) ◽  
pp. 784-788 ◽  
Author(s):  
M. N. Sawka ◽  
R. M. Glaser ◽  
S. W. Wilde ◽  
T. C. von Luhrte
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Pulmonary Ventilation ◽  
Rate Pressure Product ◽  
Wheelchair Propulsion ◽  
Arm Cranking ◽  
Ventilatory Equivalent ◽  
Arm Crank Ergometer ◽  
Oxygen Difference ◽  
Equal Power

To compare metabolic and circulatory responses for wheelchair ergometer (WERG) and arm crank ergometer (ACE) exercise at equal power-output (PO) levels, wheelchair-dependent (n = 7) and able-bodied (n = 10) subjects exercised at PO levels at 30, 90, 150, and 210 kpm times min-1 for each mode of ergometry. Steady-state values of oxygen uptake (VO2), pulmonary ventilation (VE), ventilatory equivalent of oxygen (VE times VO2-1), cardiac output (Q), stroke volume (SV), arteriovenous oxygen difference (a-VO2), heart rate (HR), systolic blood pressure (SBP), and rate pressure product (RPP) were determined at each PO. With the exception of VE times VO2-1 and a-VO2, each variable tended to increase with PO. Generally, VO2, VE, Q, SV, HR, SBP, and RPP responses were higher for WERG than ACE exercise at each PO level. When Q and RPP were expressed in relation to VO2, both variables were higher for WERG exercise. These data suggest that the wheelchair hand-rim system is inherently more strenuous than arm cranking, and that the latter should be studied further as an alternative method for wheelchair propulsion.

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