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.

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.

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.

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.

Understanding cognitive performance during exercise in Reserve Officers’ Training Corps: establishing the executive function-exercise intensity relationship

2020 ◽  
Vol 129 (4) ◽  
pp. 846-854
Author(s):  
Brandon L. Stone ◽  
Madison Beneda-Bender ◽  
Duncan L. McCollum ◽  
Jongjoo Sun ◽  
Joseph H. Shelley ◽  
...  
Keyword(s):  
Heart Rate ◽  
Executive Function ◽  
Executive Functioning ◽  
Exercise Intensity ◽  
Cognitive Change ◽  
Heart Rate Reserve ◽  
Graded Exercise ◽  
The Brain ◽  
Training Corps ◽  
Reserve Officers Training Corps

The executive functioning aspect of cognition was evaluated during graded exercise in Reserve Officers’ Training Corps cadets. Executive function declined at exercise intensities of ≥80% of heart rate reserve. The decline in executive function was coupled with declines in the oxygenation of the prefrontal cortex, the brain region responsible for executive functioning. These data define the executive function-exercise intensity relationship and provide evidence supporting the reticular activation hypofrontality theory as a model of cognitive change.

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.

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