1163 EFFECT OF SUCCESSIVE RAMP EXERCISE TESTS TO FATIGUE ON VENTILATORY CONTROL AND GAS EXCHANGE

1994 ◽  
Vol 26 (Supplement) ◽  
pp. S207
Author(s):  
B. W. Scheuermann ◽  
J. M. Kowalchuk
2019 ◽  
Vol 317 (6) ◽  
pp. R840-R851 ◽  
Author(s):  
Danilo Iannetta ◽  
Louis Passfield ◽  
Ahmad Qahtani ◽  
Martin J. MacInnis ◽  
Juan M. Murias

It is typically assumed that in the context of double-leg cycling, dominant (DOMLEG) and nondominant legs (NDOMLEG) have similar aerobic capacity and both contribute equally to the whole body physiological responses. However, there is a paucity of studies that have systematically investigated maximal and submaximal aerobic performance and characterized the profiles of local muscle deoxygenation in relation to leg dominance. Using counterweighted single-leg cycling, this study explored whether peak O2 consumption (V̇o2peak), maximal lactate steady-state (MLSSp), and profiles of local deoxygenation [HHb] would be different in the DOMLEG compared with the NDOMLEG. Twelve participants performed a series of double-leg and counterweighted single-leg DOMLEG and NDOMLEG ramp-exercise tests and 30-min constant-load trials. V̇o2peak was greater in the DOMLEG than in the NDOMLEG (2.87 ± 0.42 vs. 2.70 ± 0.39 L/min, P < 0.05). The difference in V̇o2peak persisted even after accounting for lean mass ( P < 0.05). Similarly, MLSSp was greater in the DOMLEG than in the NDOMLEG (118 ± 31 vs. 109 ± 31 W; P < 0.05). Furthermore, the amplitude of the [HHb] signal during ramp exercise was larger in the DOMLEG than in the NDOMLEG during both double-leg (26.0 ± 8.4 vs. 20.2 ± 8.8 µM, P < 0.05) and counterweighted single-leg cycling (18.5 ± 7.9 vs. 14.9 ± 7.5 µM, P < 0.05). Additionally, the amplitudes of the [HHb] signal were highly to moderately correlated with the mode-specific V̇o2peak values (ranging from 0.91 to 0.54). These findings showed in a group of young men that maximal and submaximal aerobic capacities were greater in the DOMLEG than in the NDOMLEG and that superior peripheral adaptations of the DOMLEG may underpin these differences.


2018 ◽  
Vol 43 (12) ◽  
pp. 1288-1297 ◽  
Author(s):  
Oliver J. Chrzanowski-Smith ◽  
Robert M. Edinburgh ◽  
James A. Betts ◽  
Keith A. Stokes ◽  
Javier T. Gonzalez

The maximal capacity to utilise fat (peak fat oxidation, PFO) may have implications for health and ultra-endurance performance and is commonly determined by incremental exercise tests employing 3-min stages. However, 3-min stages may be insufficient to attain steady-state gas kinetics, compromising test validity. We assessed whether 4-min stages produce steady-state gas exchange and reliable PFO estimates in adults with peak oxygen consumption < 40 mL·kg−1·min−1. Fifteen participants (9 females) completed a graded test to determine PFO and the intensity at which this occurred (FATMAX). Three short continuous exercise sessions (SCE) were then completed in a randomised order, involving completion of the graded test to the stage (i) preceding, (ii) equal to (SCEequal), or (iii) after the stage at which PFO was previously attained, whereupon participants then continued to cycle for 10 min at that respective intensity. Expired gases were sampled at minutes 3–4, 5–6, 7–8, and 9–10. Individual data showed steady-state gas exchange was achieved within 4 min during SCEequal. Mean fat oxidation rates were not different across time within SCEequal nor compared with the graded test at FATMAX (both p > 0.05). However, the graded test displayed poor surrogate validity (SCEequal, minutes 3–4 vs. 5–6, 7–8, and 9–10) and day-to-day reliability (minutes 3–4, SCEequal vs. graded test) to determine PFO, as evident by correlations (range: 0.47–0.83) and typical errors and 95% limits of agreement (ranges: 0.03–0.05 and ±0.09–0.15 g·min−1, respectively). In conclusion, intraindividual variation in PFO is substantial despite 4-min stages establishing steady-state gas exchange in individuals with low fitness. Individual assessment of PFO may require multiple assessments.


1980 ◽  
Vol 49 (3) ◽  
pp. 456-461 ◽  
Author(s):  
D. Y. Sue ◽  
J. E. Hansen ◽  
M. Blais ◽  
K. Wasserman

Although exercise testing is useful in the diagnosis and management of cardiovascular and pulmonary diseases, a rapid comprehensive method for measurement of ventilation and gas exchange has been limited to expensive complex computer-based systems. We devised a relatively inexpensive, technically simple, and clinically oriented exercise system built around a desktop calculator. This system automatically collects and analyzes data on a breath-by-breath basis. Our calculator system overcomes the potential inaccuracies of gas exchange measurement due to water vapor dilution and mismatching of expired flow and gas concentrations. We found no difference between the calculator-derived minute ventilation, CO2 production, O2 consumption, and respiratory exchange ratio and the values determined from simultaneous mixed expired gas collections in 30 constant-work-rate exercise studies. Both tabular and graphic displays of minute ventilation, CO2 production, O2 consumption, respiratory exchange ratio, heart rate, end-tidal O2 tension, end-tidal CO2 tension, and arterial blood gas value are included for aid in the interpretation of clinical exercise tests.


2007 ◽  
Vol 102 (4) ◽  
pp. 403-410 ◽  
Author(s):  
David C. Poole ◽  
Daryl P. Wilkerson ◽  
Andrew M. Jones

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Benoit Wallaert ◽  
Lidwine Wemeau-Stervinou ◽  
Julia Salleron ◽  
Isabelle Tillie-Leblond ◽  
Thierry Perez

In patients with fibrotic idiopathic interstitial pneumonia (f-IIP), the diffusing capacity for carbon monoxide (DLCO) has been used to predict abnormal gas exchange in the lung. However, abnormal values for arterial blood gases during exercise are likely to be the most sensitive manifestations of lung disease. The aim of this study was to compare DLCO, resting PaO2, P(A-a)O2at cardiopulmonary exercise testing peak, and oxygen desaturation during a 6-min walk test (6MWT). Results were obtained in 121 patients with idiopathic pulmonary fibrosis (IPF,n=88) and fibrotic nonspecific interstitial pneumonias (NSIP,n=33). All but 3 patients (97.5%) had low DLCO values (<LLN) whereas only 66.6% had low KCO; 42 patients (65%) exhibited resting hypoxemia (<75 mmHg); 112 patients (92.5%) exhibited a high P[(A-a)O2], peak (>35 mmHg) and 100 (83%) demonstrated significant oxygen desaturation during 6MWT (>4%). Interestingly 27 patients had low DLCO and normal P(A-a)O2, peak and/or no desaturation during the 6MWT. The 3 patients with normal DLCO also had normal PaO2, normal P(A-a)O2, peak, and normal oxygen saturation during 6MWT. Our results demonstrate that in fibrotic IIP, DLCO better defines impairment of pulmonary gas exchange than resting PaO2, exercise P(A-a)O2, peak, or 6MWT SpO2.


1985 ◽  
Vol 17 (2) ◽  
pp. 217
Author(s):  
R. L. Hughson ◽  
C. W. Bennett ◽  
M. D. Inman ◽  
H. J. Green ◽  
D. Ursino
Keyword(s):  

1989 ◽  
Vol 66 (6) ◽  
pp. 2491-2495 ◽  
Author(s):  
S. K. Powers ◽  
J. Lawler ◽  
J. A. Dempsey ◽  
S. Dodd ◽  
G. Landry

Recent evidence suggests that heavy exercise may lower the percentage of O2 bound to hemoglobin (%SaO2) by greater than or equal to 5% below resting values in some highly trained endurance athletes. We tested the hypothesis that pulmonary gas exchange limitations may restrict VO2max in highly trained athletes who exhibit exercise-induced hypoxemia. Twenty healthy male volunteers were divided into two groups according to their physical fitness status and the demonstration of exercise-induced reductions in %SaO2 less than or equal to 92%: 1) trained (T), mean VO2max = 56.5 ml.kg-1.min-1 (n = 13) and 2) highly trained (HT) with maximal exercise %SaO2 less than or equal to 92%, mean VO2max = 70.1 ml.kg-1.min-1 (n = 7). Subjects performed two incremental cycle ergometer exercise tests to determine VO2max at sea level under normoxic (21% O2) and mild hyperoxic conditions (26% O2). Mean %SaO2 during maximal exercise was significantly higher (P less than 0.05) during hyperoxia compared with normoxia in both the T group (94.1 vs. 96.1%) and the HT group (90.6 vs. 95.9%). Mean VO2max was significantly elevated (P less than 0.05) during hyperoxia compared with normoxia in the HT group (74.7 vs. 70.1 ml.kg-1.min-1). In contrast, in the T group, no mean difference (P less than 0.05) existed between treatments in VO2max (56.5 vs. 57.1 ml.kg-1.min-1). These data suggest that pulmonary gas exchange may contribute significantly to the limitation of VO2max in highly trained athletes who exhibit exercise-induced reductions in %SaO2 at sea level.(ABSTRACT TRUNCATED AT 250 WORDS)


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