Adjustment for gas exchange threshold enhances precision of heart rate-derived VO2 estimates during heavy exercise

2008 ◽  
Vol 33 (1) ◽  
pp. 68-74 ◽  
Author(s):  
Robert W. Pettitt ◽  
J. David Symons ◽  
Julie E. Taylor ◽  
Patricia A. Eisenman ◽  
Andrea T. White
Keyword(s):  
Heart Rate ◽  
Gas Exchange ◽  
Oxygen Uptake ◽  
Interval Training ◽  
Heart Rate Reserve ◽  
Heavy Exercise ◽  
Model Interaction ◽  
Fitness Level ◽  
The Difference ◽  
Gas Exchange Threshold

Overestimates of oxygen uptake (VO2) are derived from the heart rate reserve – VO2 reserve (HRR–VO2R) model. We tested the hypothesis that adjusting for differences above and below gas exchange threshold (HRR–GET model) would tighten the precision of HR-derived VO2 estimates during heavy exercise. Seven men and 7 women of various VO2 max levels, on 2 separate days, cycled for 6 min at intensities equal to power at GET, 15% the difference between GET and VO2 max (15% above), and at 30% above GET. A second bout at 15% above GET (15% above (bout 2)) after 3 min of recovery was performed to assess estimates during interval training. Actual VO2 was compared with estimates derived from the HRR–VO2R and the HRR–GET. VO2 values were summed over the 6 min duration of data collection (6 min LO2) and compared with Bland–Altman plots. HRR–VO2R yielded 6 min LO2 (±2 SD) overestimates of 2.0 (±2.5), 1.9 (±2.7), and 1.3 (±3.3) for GET, 15% over, and 30% over, respectively, whereas corresponding 6 min LO2 difference values for the HRR–GET model were –0.42 (±1.6), –0.23 (±1.1), and –0.55 (±1.8), respectively. For 15% above (bout 2), the 6 min LO2 difference for HRR–VO2R was 1.8 (±2.9), whereas the difference for HRR–GET was 0.17 (±1.4). The 6 min LO2 values relative to the subjects’ VO2 max did not vary (r = 0.05 to 0.36); therefore, fitness level did not affect estimates. Sex did not affect accuracy of either estimate model (sex X estimate model interaction, p > 0.95). We observed accurate estimates from the HRR–GET model during heavy exercise.

Gas Exchange Anaerobic Threshold: Implications for Exercise Prescription in Children

1992 ◽  
Vol 4 (4) ◽  
pp. 360-366 ◽  
Author(s):  
Timothy R. McConnell ◽  
Jean H. Haas ◽  
Nancy C. Conlin
Keyword(s):  
Heart Rate ◽  
Gas Exchange ◽  
Oxygen Uptake ◽  
Anaerobic Threshold ◽  
Exercise Intensity ◽  
Exercise Prescription ◽  
Maximal Heart Rate ◽  
Heart Rate Reserve ◽  
Current Population

Thirty-eight children (mean age 12.2 ±3.6 yrs) were tested to (a) compare the training heart rate (HR) and oxygen uptake (V̇O2) computed from commonly used exercise prescription methods to the heart rate (HRAT) and V̇O2 (ATge) at the gas exchange anaerobic threshold, (b) compute the range of relative HRs and V̇O2s (% HRmax and % V̇O2max, respectively) at which the ATge occurred, and (c) discuss the implications for prescribing exercise intensity. The ATge occurred at a V̇O2 of 20.9 ml · kg−1 · min−1 and an HR of 129 beats·min−1. The training HR and V̇O2 computed using 70 and 85% HRmax, 70% of the maximal heart rate reserve (HRR), and 57 and 78% V·O2max, were significantly different (p<.05) from their corresponding ATge values. To compute training % HRmax, % V̇O2max, and % HRR values that would not significantly differ from the ATge, then 68% HRmax, 48% V̇O2max, and 41% HRR would need to be used for the current population.

Validation of a Maximal Incremental Skating Test Performed on a Slide Board: Comparison With Treadmill Skating

2017 ◽  
Vol 12 (10) ◽  
pp. 1363-1369 ◽  
Author(s):  
Tatiane Piucco ◽  
Fernando Diefenthaeler ◽  
Rogério Soares ◽  
Juan M. Murias ◽  
Guillaume Y. Millet
Keyword(s):  
Heart Rate ◽  
Gas Exchange ◽  
Oxygen Uptake ◽  
Endurance Performance ◽  
Criterion Validity ◽  
Compensation Point ◽  
Respiratory Compensation Point ◽  
Respiratory Compensation ◽  
Gas Exchange Threshold

Purpose: To investigate the criterion validity of a maximal incremental skating test performed on a slide board (SB). Methods: Twelve subelite speed skaters performed a maximal skating test on a treadmill and on a SB. Gas exchange threshold (GET), respiratory compensation point (RCP), and maximal variables were determined. Results: Oxygen uptake () (31.0 ± 3.2 and 31.4 ± 4.1 mL·min−1·kg−1), percentage of maximal () (66.3 ± 4 and 67.7 ± 7.1%), HR (153 ± 14 and 150 ±12 bpm), and ventilation (59.8 ± 11.8 and 57.0 ± 10.7 L·min−1) at GET, and (42.5 ± 4.4 and 42.9 ± 4.8 mL·min−1·kg−1), percentage of (91.1 ± 3.3 and 92.4 ± 2.1%), heart rate (HR) (178 ± 9 and 178 ± 6 bpm), and ventilation (96.5 ± 19.2 and 92.1 ± 12.7 L·min−1) at RCP were not different between skating on a treadmill and on a SB. (46.7 ± 4.4 vs 46.4 ±6.1 mL·min−1·kg−1) and maximal HR (195 ± 6 vs 196 ± 10 bpm) were not significantly different and correlated (r = .80 and r = .87, respectively; P < .05) between the treadmill and SB. at GET, RCP, and obtained on a SB were correlated (r > .8) with athletes’ best times on 1500 m. Conclusions: The incremental skating test on a SB was capable to distinguish maximal ( and HR) and submaximal (, % , HR, and ventilation) parameters known to determine endurance performance. Therefore, the SB test can be considered as a specific and practical alternative to evaluate speed skaters.

Kinetics of oxygen uptake during supine and upright heavy exercise

1999 ◽  
Vol 87 (1) ◽  
pp. 253-260 ◽  
Author(s):  
Shunsaku Koga ◽  
Tomoyuki Shiojiri ◽  
Manabu Shibasaki ◽  
Narihiko Kondo ◽  
Yoshiyuki Fukuba ◽  
...  
Keyword(s):  
Heart Rate ◽  
Oxygen Uptake ◽  
Supine Position ◽  
Slow Component ◽  
Fast Component ◽  
Heavy Exercise ◽  
The Difference ◽  
Early Rise ◽  
Kinetics Of ◽  
State Increase

It is presently unclear how the fast and slow components of pulmonary oxygen uptake (V˙o 2) kinetics would be altered by body posture during heavy exercise [i.e., above the lactate threshold (LT)]. Nine subjects performed transitions from unloaded cycling to work rates representing moderate (below the estimated LT) and heavy exercise (V˙o 2 equal to 50% of the difference between LT and peakV˙o 2) under conditions of upright and supine positions. During moderate exercise, the steady-state increase in V˙o 2was similar in the two positions, butV˙o 2 kinetics were slower in the supine position. During heavy exercise, the rate of adjustment ofV˙o 2 to the 6-min value was also slower in the supine position but was characterized by a significant reduction in the amplitude of the fast component ofV˙o 2, without a significant slowing of the phase 2 time constant. However, the amplitude of the slow component was significantly increased, such that the end-exerciseV˙o 2 was the same in the two positions. The changes inV˙o 2 kinetics for the supine vs. upright position were paralleled by a blunted response of heart rate at 2 min into exercise during supine compared with upright heavy exercise. Thus the supine position was associated with not only a greater amplitude of the slow component forV˙o 2 but also, concomitantly, with a reduced amplitude of the fast component; this latter effect may be due, at least in part, to an attenuated early rise in heart rate in the supine position.

scholarly journals Exercise chronotropic incompetence phenotypes the level of cardiovascular risk and exercise gas exchange impairment in the general population. An analysis of the Euro-EX prevention trial

2019 ◽  
Vol 27 (5) ◽  
pp. 526-535 ◽  
Author(s):  
Pietro Laforgia ◽  
Francesco Bandera ◽  
Eleonora Alfonzetti ◽  
Marco Guazzi
Keyword(s):  
Heart Rate ◽  
Cardiovascular Risk ◽  
Gas Exchange ◽  
Left Ventricular ◽  
Prevention Trial ◽  
Volume Index ◽  
Maximal Heart Rate ◽  
Heart Rate Reserve ◽  
Peak Heart Rate ◽  
Apparently Healthy

Background Chronotropic insufficiency (CI) is defined as the inability of the heart to increase its rate commensurate with increased demand. Exercise CI is an established predictor of major adverse cardiovascular events in patients with cardiovascular diseases. Aim The aim of this study was to evaluate how exercise CI phenotypes different levels of cardiovascular risk and how it may better perform in defining cardiovascular risk when analysed in the context of cardiopulmonary exercise test (CPET)-derived measures and standard echocardiography in a healthy population with variable cardiovascular risk profile. Methods Apparently healthy individuals ( N = 702, 53.8% females) with at least one major cardiovascular risk factor (MCVRF; hypertension, diabetes, tabagism, dyslipidaemia, body mass index > 25), enrolled in the Euro-EX prevention trial, underwent CPET. CI was defined as the inability to reach 80% of the chronotropic index, that is, the ratio of peak heart rate – rest heart rate/peak heart rate – age predicted maximal heart rate (AMPHR: 220 – age), they were divided into four groups according to the heart rate reserve (<80%>) and respiratory gas exchange ratio (RER; < 1.05>) as a marker of achieved maximal performance. Subjects with a RER < 1.05 ( n = 103) were excluded and the final population ( n = 599) was divided into CI group ( n = 472) and no-CI group ( n = 177). Results Compared with no-CI, CI subjects were more frequently females with a history of hypertension in a high rate. CI subjects also exhibited a significantly lower peak oxygen uptake (VO2) and circulatory power and an echocardiographic pattern indicative of higher left atrial volume index and left ventricular mass index. An inverse stepwise relationship between heart rate reserve and number of MCVRFs was observed (one MCVRF: 0.71 ± 0.23; two MCVRFs: 0.68 ± 0.24, three MCVRFs: 0.64 ± 0.20; four MCVRFs: 0.64 ± 0.23; five MCVRFs: 0.57 ± 18; p < 0.01). In multivariate analysis the only variable found predicting CI was peak VO2 ( p < 0.05; odds ratio 0.91; confidence interval 0.85–0.97). Conclusions In a population of apparently healthy subjects, exercise CI is common and phenotypes the progressive level of cardiovascular risk by a tight relationship with MCVRFs. CI patients exhibit some peculiar abnormal exercise gas exchange patterns (lower peak VO2 and exercise oscillatory ventilation) and echo-derived measures (higher left atrium size and left ventricle mass) that may well anticipate evolution toward heart failure.

scholarly journals Longitudinal Changes in the Oxygen Uptake Kinetic Response to Heavy-Intensity Exercise in 14- to 16-Year-Old Boys

2010 ◽  
Vol 22 (2) ◽  
pp. 314-325 ◽  
Author(s):  
Brynmor C. Breese ◽  
Craig A. Williams ◽  
Alan R. Barker ◽  
Joanne R. Welsman ◽  
Samantha G. Fawkner ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Slow Component ◽  
Uptake Kinetic ◽  
Pulmonary Oxygen Uptake ◽  
Longitudinal Changes ◽  
Age Dependent ◽  
Constant Work Rate ◽  
Exercise Transitions ◽  
The Difference ◽  
Gas Exchange Threshold

This study examined longitudinal changes in the pulmonary oxygen uptake (pV̇O2) kinetic response to heavy-intensity exercise in 14–16 yr old boys. Fourteen healthy boys (age 14.1 ± 0.2 yr) completed exercise testing on two occasions with a 2-yr interval. Each participant completed a minimum of three ‘step’ exercise transitions, from unloaded pedalling to a constant work rate corresponding to 40% of the difference between the pV̇O2 at the gas exchange threshold and peak pV̇O2 (40% Δ). Over the 2-yr period a significant increase in the phase II time constant (25 ± 5 vs. 30 ± 5 s; p = .002, ω2 = 0.34), the relative amplitude of the pV̇O2 slow component (9 ± 5 vs. 13 ± 4%; p = .036, ω2 = 0.14) and the pV̇O2 gain at end-exercise (11.6 ± 0.6 vs. 12.4 ± 0.7 mL·min−1·W−1; p < .001, ω2 = 0.42) were observed. These data indicate that the control of oxidative phosphorylation in response to heavy-intensity cycling exercise is age-dependent in teenage boys.

Abstract P319: Association of Heart Rate Reserve with Incidence of Hypertension in Men

Circulation ◽  
2013 ◽  
Vol 127 (suppl_12) ◽  
Author(s):  
Vivek K Prasad ◽  
Gregory A Hand ◽  
Mei Sui ◽  
Duck C Lee ◽  
Deepika Shrestha ◽  
...  
Keyword(s):  
Heart Rate ◽  
Exercise Test ◽  
Heavy Drinking ◽  
Risk Groups ◽  
Hazard Ratio ◽  
Maximal Heart Rate ◽  
Heart Rate Reserve ◽  
Incident Hypertension ◽  
The Difference ◽  
Design And Methods

Abstract Objectives— We examined the association between heart rate reserve (HRR) and incident hypertension in men in the Aerobics Center Longitudinal Study. Research design and Methods— A total of 10418 healthy normotensive men, who did not have an abnormal electrocardiogram or a history of heart attack, stroke, cancer, or diabetes, performed a maximal treadmill exercise test and were followed for the incidence of hypertension. HRR was defined as the difference between maximal heart rate during exercise test and resting heart rate. Results— During a mean follow-up of 6 years, there were 2831 cases of incident hypertension. Compared with men in the reference category (the lowest quartile of HRR), the risk of incident hypertension was significantly lower in the highest quartile of HRR with a hazard ratio 0.67 (95% CI: 0.60-0.75) when adjusted for age and baseline examination year. Further adjustment for smoking, heavy drinking, body mass index (BMI), resting systolic and diastolic blood pressure, cholesterol, blood glucose and cardio respiratory fitness, resulted a hazard ratio of 0.84 (95% CI:0.74-0.95). This result was almost similar when we stratified them into younger and older men with hazard ratio of 0.77(95% CI: 0.62-0.98) and 0.78 (95% CI: 0.66-0.90) respectively. We also found a significant lower hypertension risk associated with higher HRR among high risk groups such as overweight, low fitness, or prehypertension with hazard ratio of 0.82(95% CI:0.70-0.97), 0.80(95% CI:0.67-0.96), 0.76(95% CI:0.64-0.88) respectively. Conclusion— Risk of Incident hypertension was significantly lower in men with higher HRR. High HRR was also associated with lower risk of developing hypertension irrespective of age and status of risk factors such as high BMI, low fitness and prehypertension. Therefore, HRR may be considered as a reliable exercise parameter for predicting the risk of incident hypertension.

scholarly journals Coca chewing for exercise: hormonal and metabolic responses of nonhabitual chewers

1996 ◽  
Vol 81 (5) ◽  
pp. 1901-1907 ◽  
Author(s):  
Roland Favier ◽  
Esperanza Caceres ◽  
Laurent Guillon ◽  
Brigitte Sempore ◽  
Michel Sauvain ◽  
...  
Keyword(s):  
Heart Rate ◽  
Gas Exchange ◽  
Oxygen Uptake ◽  
Metabolic Responses ◽  
Physiological Data ◽  
Respiratory Gas Exchange ◽  
Gum Chewing ◽  
Arterial Blood ◽  
Before And After ◽  
Exercise Induced

Favier, Roland, Esperanza Caceres, Laurent Guillon, Brigitte Sempore, Michel Sauvain, Harry Koubi, and Hilde Spielvogel. Coca chewing for exercise: hormonal and metabolic responses of nonhabitual chewers. J. Appl. Physiol. 81(5): 1901–1907, 1996.—To determine the effects of acute coca use on the hormonal and metabolic responses to exercise, 12 healthy nonhabitual coca users were submitted twice to steady-state exercise (∼75% maximal O2 uptake). On one occasion, they were asked to chew 15 g of coca leaves 1 h before exercise, whereas on the other occasion, exercise was performed after 1 h of chewing a sugar-free chewing gum. Plasma epinephrine, norepinephrine, insulin, glucagon, and metabolites (glucose, lactate, glycerol, and free fatty acids) were determined at rest before and after coca chewing and during the 5th, 15th, 30th, and 60th min of exercise. Simultaneously to these determinations, cardiorespiratory variables (heart rate, mean arterial blood pressure, oxygen uptake, and respiratory gas exchange ratio) were also measured. At rest, coca chewing had no effect on plasma hormonal and metabolic levels except for a significantly reduced insulin concentration. During exercise, the oxygen uptake, heart rate, and respiratory gas exchange ratio were significantly increased in the coca-chewing trial compared with the control (gum-chewing) test. The exercise-induced drop in plasma glucose and insulin was prevented by prior coca chewing. These results contrast with previous data obtained in chronic coca users who display during prolonged submaximal exercise an exaggerated plasma sympathetic response, an enhanced availability and utilization of fat (R. Favier, E. Caceres, H. Koubi, B. Sempore, M. Sauvain, and H. Spielvogel. J. Appl. Physiol. 80: 650–655, 1996). We conclude that, whereas coca chewing might affect glucose homeostasis during exercise, none of the physiological data provided by this study would suggest that acute coca chewing in nonhabitual users could enhance tolerance to exercise.

Perceived Exertion during Physical Exercise among Individuals High and Low in Fitness

1996 ◽  
Vol 82 (2) ◽  
pp. 419-424 ◽  
Author(s):  
Antonios K. Travlos ◽  
Daniel Q. Marisi
Keyword(s):  
Heart Rate ◽  
Physical Exercise ◽  
Oxygen Uptake ◽  
Core Temperature ◽  
Maximal Oxygen Uptake ◽  
Perceived Exertion ◽  
Cycle Ergometer ◽  
Ratings Of Perceived Exertion ◽  
Workload Analysis ◽  
Fitness Level

This study was conducted to investigate the influence of fitness level and gradually increased amounts of exercise on individuals' ratings of perceived exertion (RPE). 20 men served as paid subjects. They were divided into groups of high (>56 ml/kg/min.) and low fitness (<46 ml/kg/min.) according to their maximal oxygen uptake (VO2 max). Participants were required to pedal on a cycle ergometer at a progressively increased workload (every 10 min.) corresponding to 40, 50, 60, 70, and 80% of individual VO2 max values. Heart rates, RPE, and core temperatures were recorded every 5th minute after the initiation of exercising at a specific workload. Analysis indicated that, when controlling for VO2 max values, elevations of heart rate and core temperature were not affected by fitness. However, highly fit individuals perceived themselves under less exertion than did the group low in fitness. Correlations showed that, taking into consideration fitness, there is a stronger relationship between RPE and heart rate and RPE and core temperature for the highly fit individuals than for the less fit.

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