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.

Ischemic preconditioning of the muscle improves maximal exercise performance but not maximal oxygen uptake in humans

2011 ◽  
Vol 111 (2) ◽  
pp. 530-536 ◽  
Author(s):  
Antonio Crisafulli ◽  
Flavio Tangianu ◽  
Filippo Tocco ◽  
Alberto Concu ◽  
Ombretta Mameli ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Ischemic Preconditioning ◽  
Exercise Performance ◽  
Cell Injury ◽  
Maximal Exercise ◽  
Pulmonary Ventilation ◽  
Anaerobic Capacity ◽  
Maximal Heart Rate ◽  
Exercise Tests ◽  
Maximal Power Output

Brief episodes of nonlethal ischemia, commonly known as “ischemic preconditioning” (IP), are protective against cell injury induced by infarction. Moreover, muscle IP has been found capable of improving exercise performance. The aim of the study was the comparison of standard exercise performances carried out in normal conditions with those carried out following IP, achieved by brief muscle ischemia at rest (RIP) and after exercise (EIP). Seventeen physically active, healthy male subjects performed three incremental, randomly assigned maximal exercise tests on a cycle ergometer up to exhaustion. One was the reference (REF) test, whereas the others were performed after the RIP and EIP sessions. Total exercise time (TET), total work (TW), and maximal power output (Wmax), oxygen uptake (VO2max), and pulmonary ventilation (VEmax) were assessed. Furthermore, impedance cardiography was used to measure maximal heart rate (HRmax), stroke volume (SVmax), and cardiac output (COmax). A subgroup of volunteers ( n = 10) performed all-out tests to assess their anaerobic capacity. We found that both RIP and EIP protocols increased in a similar fashion TET, TW, Wmax, VEmax, and HRmax with respect to the REF test. In particular, Wmax increased by ∼4% in both preconditioning procedures. However, preconditioning sessions failed to increase traditionally measured variables such as VO2max, SVmax, COmax, and anaerobic capacity. It was concluded that muscle IP improves performance without any difference between RIP and EIP procedures. The mechanism of this effect could be related to changes in fatigue perception.

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.

Habituation of Children to Treadmill Walking and Running: Metabolic and Kinematic Criteria

1995 ◽  
Vol 7 (2) ◽  
pp. 162-175 ◽  
Author(s):  
Gail Frost ◽  
Oded Bar-Or ◽  
James Dowling ◽  
Catherine White
Keyword(s):  
Heart Rate ◽  
Steady State ◽  
Oxygen Uptake ◽  
Stride Length ◽  
Respiratory Exchange Ratio ◽  
Treadmill Exercise ◽  
A Priori ◽  
Treadmill Walking ◽  
Stride Rate ◽  
The Stability

This study examined habituation to treadmill walking or running in children. Twenty-four boys and girls, ages 7–11, completed six 6-min trials of treadmill exercise at one of these speeds: (a) comfortable walking pace (CWP), (b) CWP + 15%, (c) running at CWP + 3 km·hr−1, or (d) running as above + 15%. The six trials were repeated in a second visit. The a priori criterion for habituation was a decrease in steady state values of oxygen uptake (V̇O2), heart rate (HR), respiratory exchange ratio (RER), and stride rate (SR) or an increase in stride length (SL) and hip joint vertical amplitude (HA) from one trial to the next. There was no consistent pattern indicating habituation for the group. Many trials and more than one day of testing do not appear to improve the stability of the metabolic or kinematic variables. The lack of consistency in individual responses suggests that monitoring subjects’ habituation individually is important.

scholarly journals Effects of Heart Rate vs. Speed-Based High Intensity Interval Training on Aerobic and Anaerobic Capacity of Female Soccer Players

Sports ◽  
2017 ◽  
Vol 5 (3) ◽  
pp. 57 ◽  
Author(s):  
Hamid Arazi ◽  
Abbas Keihaniyan ◽  
Amin EatemadyBoroujeni ◽  
Amir Oftade ◽  
Sheida Takhsha ◽  
...  
Keyword(s):  
Heart Rate ◽  
High Intensity ◽  
Anaerobic Capacity ◽  
Interval Training ◽  
Soccer Players ◽  
High Intensity Interval Training ◽  
High Intensity Interval ◽  
Aerobic And Anaerobic

The relationship between oxygen uptake reserve and heart rate reserve is affected by intensity and duration during aerobic exercise at constant work rate

2011 ◽  
Vol 36 (6) ◽  
pp. 839-847 ◽  
Author(s):  
Felipe A. Cunha ◽  
Adrian W. Midgley ◽  
Walace D. Monteiro ◽  
Felipe K. Campos ◽  
Paulo T.V. Farinatti
Keyword(s):  
Heart Rate ◽  
Oxygen Uptake ◽  
Exercise Testing ◽  
Exercise Intensity ◽  
Maximal Exercise ◽  
Work Rate ◽  
Heart Rate Reserve ◽  
Constant Work Rate ◽  
The Stability ◽  
The Relationship

The relationship between the percentage of heart rate reserve (%HRR) and percentage of oxygen uptake reserve (%VO2R) has been recommended for prescribing aerobic exercise intensity. However, this relationship was derived from progressive maximal exercise testing data, and the stability of the relationship during prolonged exercise at a constant work rate has not been established. The main aim of this study was to investigate the stability of the %VO2R–%HRR relationship during prolonged treadmill exercise bouts performed at 3 different constant work rates. Twenty-eight men performed 4 exercise tests: (i) a ramp-incremental maximal exercise test to determine maximal heart rate (HRmax) and maximal oxygen uptake (VO2max) and (ii) three 40-min exercise bouts at 60%, 70%, and 80% VO2R. HR and VO2 significantly increased over time and were influenced by exercise intensity (p < 0.001 and p = 0.004, respectively). A 1:1 relationship between %HRR and %VO2R, and between %HRR and %VO2max, was not observed, with mean differences of 8% (t = 5.2, p < 0.001) and 6% (t = 4.8, p < 0.001), respectively. The VO2 values predicted from the ACSM running equation were all significantly higher than the observed VO2 values (p < 0.001 for all comparisons), whereas a difference for HR was observed only for the tenth min of exercise at 80% VO2R (p = 0.041). In conclusion, the main finding of this study was that the %HRR–%VO2R relationship determined by linear regression, obtained from progressive maximal exercise testing, did not apply to prolonged treadmill running performed at 3 work rates.

scholarly journals Metabolic consequences of β-alanine supplementation during exhaustive supramaximal cycling and 4000-m time-trial performance

2016 ◽  
Vol 41 (8) ◽  
pp. 864-871 ◽  
Author(s):  
Phillip M. Bellinger ◽  
Clare L. Minahan
Keyword(s):  
Oxygen Uptake ◽  
Power Output ◽  
Maximal Oxygen Uptake ◽  
Anaerobic Power ◽  
Anaerobic Capacity ◽  
Time Trial ◽  
Time To Exhaustion ◽  
Cycling Test ◽  
Cycling Time Trial ◽  
Aerobic And Anaerobic

The present study investigated the effects of β-alanine supplementation on the resultant blood acidosis, lactate accumulation, and energy provision during supramaximal-intensity cycling, as well as the aerobic and anaerobic contribution to power output during a 4000-m cycling time trial (TT). Seventeen trained cyclists (maximal oxygen uptake = 4.47 ± 0.55 L·min−1) were administered 6.4 g of β-alanine (n = 9) or placebo (n = 8) daily for 4 weeks. Participants performed a supramaximal cycling test to exhaustion (equivalent to 120% maximal oxygen uptake) before (PreExh) and after (PostExh) the 4-week supplementation period, as well as an additional postsupplementation supramaximal cycling test identical in duration and power output to PreExh (PostMatch). Anaerobic capacity was quantified and blood pH, lactate, and bicarbonate concentrations were measured pre-, immediately post-, and 5 min postexercise. Subjects also performed a 4000-m cycling TT before and after supplementation while the aerobic and anaerobic contributions to power output were quantified. β-Alanine supplementation increased time to exhaustion (+12.8 ± 8.2 s; P = 0.041) and anaerobic capacity (+1.1 ± 0.7 kJ; P = 0.048) in PostExh compared with PreExh. Performance time in the 4000-m TT was reduced following β-alanine supplementation (−6.3 ± 4.6 s; P = 0.034) and the mean anaerobic power output was likely to be greater (+6.2 ± 4.5 W; P = 0.035). β-Alanine supplementation increased time to exhaustion concomitant with an augmented anaerobic capacity during supramaximal intensity cycling, which was also mirrored by a meaningful increase in the anaerobic contribution to power output during a 4000-m cycling TT, resulting in an enhanced overall performance.

Cardio-Respiratory Response to Treadmill Exercise in Normal Children

1971 ◽  
Vol 40 (5) ◽  
pp. 433-442 ◽  
Author(s):  
Sandra D. Anderson ◽  
S. Godfrey
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Steady State ◽  
Respiratory Exchange Ratio ◽  
Treadmill Exercise ◽  
Physical Working Capacity ◽  
Respiratory Response ◽  
Working Capacity ◽  
Normal Children ◽  
Ventilatory Responses

1. Studies have been made of the response to running on a treadmill in forty boys and girls aged 5–15 years. 2. Each child was studied at two consecutive levels of steady-state work representing about 50% and 80% of his physical working capacity. Cardiac output was measured by the Indirect (CO2) Fick method. 3. The cardiac and ventilatory responses to exercise were similar to those seen during cycling on an ergometer except that the heart rate and the respiratory exchange ratio were a little lower. Stroke volume was the same. 4. The responses of children to running and cycling are discussed and the similarity to the responses of adults is noted.

Sign in / Sign up

Export Citation Format

Share Document