Hemodynamic and metabolic responses to self-paced and ramp-graded exercise testing protocols

Recent examinations have shown lower maximal oxygen consumption during traditional ramp (RAMP) compared with self-paced (SPV) graded exercise testing (GXT) attributed to differences in cardiac output. The current study examined the differences in hemodynamic and metabolic responses between RAMP and SPV during treadmill exercise. Sixteen recreationally trained men (aged23.7 ± 3.0 years) completed 2 separate treadmill GXT protocols. SPV consisted of five 2-min stages (10 min total) of increasing speed clamped by the Borg RPE6-20 scale. RAMP increased speed by 0.16 km/h every 15 s until volitional exhaustion. All testing was performed at 3% incline. Oxygen consumption was measured via indirect calorimetry; hemodynamic function was measured via thoracic impedance and blood lactate (BLa−) was measured via portable lactate analyzer. Differences between SPV and RAMP protocols were analyzed as group means by using paired-samples t tests (R Core Team 2017). Maximal values for SPV and RAMP were similar (p > 0.05) for oxygen uptake (47.1 ± 3.4 vs. 47.4 ± 3.4 mL·kg−1·min−1), heart rate (198 ± 5 vs. 200 ± 6 beats·min−1), ventilation (158.8 ± 20.7 vs. 159.3 ± 19.0 L·min−1), cardiac output (26.9 ± 5.5 vs. 27.9 ± 4.2 L·min−1), stroke volume (SV) (145.9 ± 29.2 vs. 149.8 ± 25.3 mL·beat−1), arteriovenous oxygen difference (18.5 ± 3.1 vs. 19.7 ± 3.1 mL·dL−1), ventilatory threshold (VT) (78.2 ± 7.2 vs. 79.0% ± 7.6%), and peak BLa− (11.7 ± 2.3 vs. 11.5 ± 2.4 mmol·L−1), respectively. In conclusion, SPV elicits similar maximal hemodynamic responses in comparison to RAMP; however, SV kinetics exhibited unique characteristics based on protocol. These results support SPV as a feasible GXT protocol to identify useful fitness parameters (maximal oxygen uptake, oxygen uptake kinetics, and VT).

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GENDER DIFFERENCES IN MAXIMAL OXYGEN CONSUMPTION (VO2max) DURING GRADED EXERCISE TESTING IN CHRONIC HEART FAILURE (CHF).

Medicine & Science in Sports & Exercise ◽

10.1249/00005768-199505001-00893 ◽

1995 ◽

Vol 27 (Supplement) ◽

pp. S159

Author(s):

H. Daida ◽

T. G. Allison ◽

B. D. Johnson ◽

R. W. Squires ◽

L. J. Olson

Keyword(s):

Heart Failure ◽

Gender Differences ◽

Oxygen Consumption ◽

Chronic Heart Failure ◽

Exercise Testing ◽

Maximal Oxygen Consumption ◽

Graded Exercise Testing ◽

Graded Exercise

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Red Spinach Extract Increases Ventilatory Threshold during Graded Exercise Testing

Sports ◽

10.3390/sports5040080 ◽

2017 ◽

Vol 5 (4) ◽

pp. 80 ◽

Cited By ~ 4

Author(s):

Angelique Moore ◽

Cody Haun ◽

Wesley Kephart ◽

Angelia Holland ◽

Christopher Mobley ◽

...

Keyword(s):

Exercise Testing ◽

Ventilatory Threshold ◽

Spinach Extract ◽

Graded Exercise Testing ◽

Graded Exercise

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Graded Exercise Testing Protocols for the Determination of VO2max: Historical Perspectives, Progress, and Future Considerations

Journal of Sports Medicine ◽

10.1155/2016/3968393 ◽

2016 ◽

Vol 2016 ◽

pp. 1-12 ◽

Cited By ~ 48

Author(s):

Nicholas M. Beltz ◽

Ann L. Gibson ◽

Jeffrey M. Janot ◽

Len Kravitz ◽

Christine M. Mermier ◽

...

Keyword(s):

Exercise Testing ◽

Occupational Safety ◽

Maximal Oxygen Consumption ◽

Sport Performance ◽

Individual Variability ◽

Clinical Diagnostics ◽

Historical Perspectives ◽

Dynamic Relationship ◽

Graded Exercise Testing ◽

Graded Exercise

Graded exercise testing (GXT) is the most widely used assessment to examine the dynamic relationship between exercise and integrated physiological systems. The information from GXT can be applied across the spectrum of sport performance, occupational safety screening, research, and clinical diagnostics. The suitability of GXT to determine a valid maximal oxygen consumption (VO2max) has been under investigation for decades. Although a set of recommended criteria exists to verify attainment of VO2max, the methods that originally established these criteria have been scrutinized. Many studies do not apply identical criteria or fail to consider individual variability in physiological responses. As an alternative to using traditional criteria, recent research efforts have been directed toward using a supramaximal verification protocol performed after a GXT to confirm attainment of VO2max. Furthermore, the emergence of self-paced protocols has provided a simple, yet reliable approach to designing and administering GXT. In order to develop a standardized GXT protocol, additional research should further examine the utility of self-paced protocols used in conjunction with verification protocols to elicit and confirm attainment of VO2max.

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Measurement of Lung Diffusion and Cardiac Output with a Single Breath Gas Absorption Method During Graded Exercise Testing: Reference Values for Clinical Testing

The Open Sports Medicine Journal ◽

10.2174/1874387000903010073 ◽

2009 ◽

Vol 3 (1) ◽

pp. 73-79

Author(s):

Albert Miller ◽

Maqbool Murtuza ◽

Thomas E. Bachman

Keyword(s):

Cardiac Output ◽

Exercise Testing ◽

Gas Absorption ◽

Clinical Testing ◽

Absorption Method ◽

Lung Diffusion ◽

Single Breath ◽

Graded Exercise Testing ◽

Graded Exercise ◽

Testing Reference

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Effect of small vs large muscle mass endurance training on maximal oxygen uptake in organ transplanted recipients

Applied Physiology Nutrition and Metabolism ◽

10.1139/apnm-2020-0987 ◽

2021 ◽

pp. 1-10

Author(s):

Alessio del Torto ◽

Carlo Capelli ◽

Roberto Peressutti ◽

Adriana di Silvestre ◽

Ugolino Livi ◽

...

Keyword(s):

Cardiac Output ◽

Oxygen Consumption ◽

Oxygen Uptake ◽

Endurance Training ◽

Maximal Oxygen Consumption ◽

Factors Affecting ◽

Maximal Cardiac Output ◽

Leg Cycling ◽

Before And After ◽

Large Muscle

Maximal oxygen consumption (V̇O2max) is impaired in heart (HTx), kidney (KTx), and liver (LTx) transplanted recipients and the contribution of the cardiovascular, central, and peripheral (muscular) factors in affecting V̇O2max improvement after endurance training (ET) has never been quantified in these patients. ET protocols involving single leg cycling (SL) elicit larger improvements of the peripheral factors affecting O2 diffusion and utilization than the double leg (DL) cycling ET. Therefore, this study aimed to compare the effects of SL-ET vs DL-ET on V̇O2max. We determined the DL-V̇O2max and maximal cardiac output before and after 24 SL-ET vs DL-ET sessions on 33 patients (HTx = 13, KTx = 11 and LTx = 9). The DL-V̇O2max increased by 13.8% ± 8.7 (p < 0.001) following the SL-ET, due to a larger maximal O2 systemic extraction; meanwhile, V̇O2max in DL-ET increased by 18.6% ± 12.7 (p < 0.001) because of concomitant central and peripheral adaptations. We speculate that in transplanted recipients, SL-ET is as effective as DL-ET to improve V̇O2max and that the impaired peripheral O2 extraction and/or utilization play an important role in limiting V̇O2max in these types of patients. Novelty: SL-ET increases V̇O2max in transplanted recipients because of improved peripheral O2 extraction and/or utilization. SL-ET is as successful as DL-ET to improve the cardiorespiratory fitness in transplanted recipients. The model of V̇O2max limitation indicates the peripheral factors as a remarkable limitation to the V̇O2max in these patients.

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Cardiovascular and Oxygen Uptake Kinetics During Sequential Heavy Cycling Exercises

Canadian Journal of Applied Physiology ◽

10.1139/h03-022 ◽

2003 ◽

Vol 28 (2) ◽

pp. 283-298 ◽

Cited By ~ 23

Author(s):

Stéphane Perrey ◽

Jodie Scott ◽

Laurent Mourot ◽

Jean-Denis Rouillon

Keyword(s):

Cardiac Output ◽

Oxygen Uptake ◽

Time Constant ◽

Impedance Cardiography ◽

Ventilatory Threshold ◽

Slow Component ◽

Oxygen Uptake Kinetics ◽

Cycle Ergometer ◽

Fast Component ◽

Heavy Exercise

The purpose of the present study was to assess the relationship between the rapidity of increased oxygen uptake [Formula: see text] and increased cardiac output (CO) during heavy exercise. Six subjects performed repeated bouts on a cycle ergometer above the ventilatory threshold (∼80% of peak [Formula: see text]) separated by 10-min recovery cycling at 35% peak [Formula: see text]. [Formula: see text] was determined breath-by-breath and CO was determined continuously by impedance cardiography. CO and [Formula: see text] values were significantly higher during the 2-min period preceding the second bout. The overall responses for [Formula: see text] and CO were significantly related and were faster during the second bout. Prior heavy exercise resulted in a significant increase in the amplitude of the fast component of [Formula: see text] with no change in the time constant and a decrease in the slow component. Under these circumstances, the amplitude of the fast component was more sensitive to prior heavy exercise than was the associated time constant. Key words: impedance cardiography, exercise transitions, cardiac output, prior exercise

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β-Adrenergic receptor number in human lymphocytes is inversely correlated with aerobic capacity

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1998.274.6.e1106 ◽

1998 ◽

Vol 274 (6) ◽

pp. E1106-E1112 ◽

Cited By ~ 3

Author(s):

Nobuharu Fujii ◽

Sachiko Homma ◽

Fumio Yamazaki ◽

Ryoko Sone ◽

Takeshi Shibata ◽

...

Keyword(s):

Oxygen Consumption ◽

Aerobic Capacity ◽

Adrenergic Receptor ◽

Ventilatory Threshold ◽

Human Lymphocytes ◽

Mrna Level ◽

Maximal Oxygen Consumption ◽

Subsequent Degradation ◽

Intracellular Compartments ◽

Model Cell

In the present study, the relationships between β-adrenergic receptor (β-AR) expression and aerobic capacity evaluated by maximal oxygen consumption ([Formula: see text]) and oxygen consumption level at ventilatory threshold (V˙o 2@VT) were investigated. Seventeen physically untrained and 25 trained men participated in the study. After supine resting, the peripheral blood was sampled for preparation of lymphocytes, the model cell used to analyze the β-AR state. The total number of β-AR in lymphocytes (β-ARtotal) was inversely correlated with theV˙o 2 max( r = −0.368; P < 0.05) and theV˙o 2@VT ( r = −0.359; P < 0.05). Similar relationships were also observed between the number of β-AR in cell surface and both V˙o 2 max( r = −0.491; P < 0.05) andV˙o 2@VT ( r = −0.498; P < 0.05). However, no correlation was obtained between the number of β-AR in intracellular compartments and eitherV˙o 2 max orV˙o 2@VT. The β2-AR mRNA level quantified by the use of competitive reverse transcription-polymerase chain reaction was inversely correlated withV˙o 2@VT ( r = −0.567; P < 0.05) and positively correlated with β-ARtotal( r = 0.521; P < 0.05). These findings suggest that the β-AR number in lymphocytes is inversely correlated with aerobic capacity. This relationship may be explained by downregulation of β-AR, including internalization with subsequent degradation of the receptors and inhibition of the β-AR biosynthesis.

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Physiological and Metabolic Responses to Exercise on Treadmill, Elliptical Trainer, and Stepper: Practical Implications for Training

International Journal of Sport Nutrition and Exercise Metabolism ◽

10.1123/ijsnem.2020-0155 ◽

2020 ◽

pp. 1-8

Author(s):

Andrew N. Bosch ◽

Kirsten C. Flanagan ◽

Maaike M. Eken ◽

Adrian Withers ◽

Jana Burger ◽

...

Keyword(s):

Heart Rate ◽

Oxygen Consumption ◽

Energy Expenditure ◽

Physiological Responses ◽

Maximal Oxygen Consumption ◽

Metabolic Responses ◽

Physiological Measures ◽

Fuel Utilization ◽

Trained Runners ◽

Practical Implications

Elliptical trainers and steppers are proposed as useful exercise modalities in the rehabilitation of injured runners due to the reduced stress on muscles and joints when compared to running. This study compared the physiological responses to submaximal running (treadmill) with exercise on the elliptical trainer and stepper devices at three submaximal but identical workloads. Authors had 18 trained runners (male/female: N = 9/9, age: mean ± SD = 23 ± 3 years) complete randomized maximal oxygen consumption tests on all three modalities. Submaximal tests of 3 min were performed at 60%, 70%, and 80% of peak workload individually established for each modality. Breath-by-breath oxygen consumption, heart rate, fuel utilization, and energy expenditure were determined. The value of maximal oxygen consumption was not different between treadmill, elliptical, and stepper (49.3 ± 5.3, 48.0 ± 6.6, and 46.7 ± 6.2 ml·min−1·kg−1, respectively). Both physiological measures (oxygen consumption and heart rate) as well as carbohydrate and fat oxidation differed significantly between the different exercise intensities (60%, 70%, and 80%) but did not differ between the treadmill, elliptical trainer, and stepper. Therefore, the elliptical trainer and stepper are suitable substitutes for running during periods when a reduced running load is required, such as during rehabilitation from running-induced injury.

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