Association between the anaerobic threshold and the break-point in the double product/work rate relationship

1996 ◽  
Vol 75 (1) ◽  
pp. 14-21 ◽  
Author(s):  
M. Riley ◽  
K. Maehara ◽  
J. P�rsz�sz ◽  
M. P. K. J. Engelen ◽  
H. Tanaka ◽  
...  
Keyword(s):  
Anaerobic Threshold ◽  
Break Point ◽  
Work Rate ◽  
Double Product ◽  
Rate Relationship

scholarly journals Association between the Ventilatory Treshold and the Break-point in the Heart Rate/Work Rate Relationship: Comparison with the Break-point in the Double Product/Work Rate

2006 ◽  
Vol 4 ◽  
pp. 499-507
Author(s):  
Jun Sugawara ◽  
Takeshi Otsuki ◽  
Takumi Tanabe ◽  
Kouki Takahashi ◽  
Ken Yamazaki ◽  
...  
Keyword(s):  
Heart Rate ◽  
Break Point ◽  
Work Rate ◽  
Double Product ◽  
Rate Relationship

Non-invasive detection of the anaerobic threshold by a neural network model of the heart rate—work rate relationship

2009 ◽  
Vol 223 (3) ◽  
pp. 109-115 ◽  
Author(s):  
A Erdogan ◽  
C Cetin ◽  
H Goksu ◽  
R Guner ◽  
M L Baydar
Keyword(s):  
Neural Network ◽  
Heart Rate ◽  
Blood Lactate ◽  
Test Data ◽  
Anaerobic Threshold ◽  
External Validation ◽  
Lactate Concentration ◽  
Work Rate ◽  
Non Invasive ◽  
Rate Relationship

The heart rates (HRs) indicating the anaerobic threshold, which corresponds to a fixed blood lactate concentration of 4mmol/l (heart rate at the onset of blood lactate accumulation (HR-OBLA)); are predicted on the basis of the heart rate—work rate relationship during exercise performance. The predictor is a multi-layer perceptron (MLP). For training and testing, 225 male soccer players (mean age, 21.6±4.5 years) performed an incremental running test on a treadmill with 3-min runs and 30-s blood sampling sessions for lactate assessment. In addition to the treadmill test data, the ages, masses, heights, body mass indices, and playing positions of half of the subjects ( n=113) were used to train the MLP and the remaining 112 were used for external validation. The results showed that the HR values recorded in the last stages before exhaustion were strong predictors of HR-OBLA ( r=0.875; standard error of estimates, 4.17). Inclusion of other parameters did not improve the prediction rate. Although additional work is needed to generalize the method to training prescription, results suggest that a neural network is a promising non-invasive tool for accurately estimating the HR-OBLA from exercise test data.

Exercise in Merino sheep dash the relationships between work intensity, endurance, anaerobic threshold and glucose metabolism

1991 ◽  
Vol 42 (4) ◽  
pp. 599 ◽  
Author(s):  
DW Pethick ◽  
CB Miller ◽  
NG Harman
Keyword(s):  
Glucose Metabolism ◽  
Anaerobic Threshold ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Work Load ◽  
Respiratory Alkalosis ◽  
Work Rate ◽  
Glycerol Concentration ◽  
Work Intensity ◽  
Intensity Of Exercise

The effect of exercise intensity on (i) the ability of sheep to sustain exercise and (ii) glucose metabolism was investigated in fed non-pregnant adult Merino ewes. Five animals were prepared with cannulae to study the splanchnic tissues using the arteriovenous difference technique either at rest or during 8 levels of exercise: 3, 5, 7 and 9 km h-1 at either 0� or 9� incline. The anaerobic threshold, determined by elevation of blood lactate concentration or lactate/pyruvate ratio, occurred at a work rate of about 6-10 watts/kg body wt (7 km h-1 on 0� incline, 3 km h-1 on 9� incline). Only exercise well in excess of the anaerobic threshold resulted in ewes showing fatigue. Fatigue was not associated with carbohydrate depletion or lacticacidosis. Changes in the partial pressure of CO2 and the pH of blood indicated a marked respiratory alkalosis that was related to the severity of exercise, suggesting that thermoregulation may have been an important component of fatigue. Splanchnic blood flow declined when the intensity of exercise exceeded the anaerobic threshold; however, this did not compromise splanchnic function as assessed by oxygen and metabolite uptake. During exercise below the anaerobic threshold euglycemia was maintained while a pronounced hyperglycemia, that became more severe as the work rate increased, was found for exercise above the anaerobic threshold. The release of glucose by the liver increased significantly at all work rates and markedly so after the anaerobic threshold, such that the resultant hyperglycemia was consistent with an exaggerated hepatic glucose release due to 'feed forward' control. The contribution of lactate and glycerol to gluconeogenesis, assuming complete conversion, remained constant at 18-25% except at the highest work load where the contribution significantly declined to 9%. The decline was due to (i) saturation of hepatic lactate uptake and (ii) a failure for glycerol concentration and so uptake to increase beyond a work rate of 22 W kg-1. The requirement for gluconeogenic end products of digestion for animals grazed under extensive conditions would be 9-30% greater than for animals not exercising, depending upon the speed and inclination of exercise.

scholarly journals Maximal Oxygen Uptake Validation in Children With Expiratory Flow Limitation

2013 ◽  
Vol 25 (1) ◽  
pp. 84-100 ◽  
Author(s):  
Katherine E. Robben ◽  
David C. Poole ◽  
Craig A. Harms
Keyword(s):  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Constant Load ◽  
Work Rate ◽  
Flow Limitation ◽  
Expiratory Flow Limitation ◽  
Test Protocol ◽  
Wide Range ◽  
Rate Relationship ◽  
Expiratory Flow

A two-test protocol (incremental/ramp (IWT) + supramaximal constant-load (CWR)) to affirm max and obviate reliance on secondary criteria has only been validated in highly fit children. In girls (n = 15) and boys (n = 12) with a wide range of VO2max (17–47 ml/kg/min), we hypothesized that this procedure would evince a VO2-WR plateau and unambiguous VO2max even in the presence of expiratory flow limitation (EFL). A plateau in the VO2-work rate relationship occurred in 75% of subjects irrespective of EFL There was a range in RER at max exercise for girls (0.97–1.14; mean 1.06 ± 0.04) and boys (0.98−1.09; mean 1.03 ± 0.03) such that 3/15 girls and 2/12 boys did not achieve the criterion RER. Moreover, in girls with RER > 1.0 it would have been possible to achieve this criterion at 78% VO2max. Boys achieved 92% VO2max at RER = 1.0. This was true also for HRmax where 8/15 girls’ and 6/12 boys’ VO2max would have been rejected based on HRmax being < 90% of age-predicted HRmax. In those who achieved the HRmax criterion, it represented a VO2 of 86% (girls) and 87% (boys) VO2max. We conclude that this two-test protocol confirms VO2max in children across a threefold range of VO2max irrespective of EFL and circumvents reliance on secondary criteria.

Identification of the Anaerobic Threshold Using Double Product in Patients With Coronary Artery Disease

1997 ◽  
Vol 79 (3) ◽  
pp. 360-362 ◽  
Author(s):  
Peter H Brubaker ◽  
Akira Kiyonaga ◽  
Brett A Matrazzo ◽  
William E Pollock ◽  
Munehiro Shindo ◽  
...  
Keyword(s):  
Coronary Artery Disease ◽  
Coronary Artery ◽  
Anaerobic Threshold ◽  
Double Product ◽  
Artery Disease

IDENTIFICATION OF THE DOUBLE PRODUCT BREAK POINT IN PATIENTS WITH CHRONIC HEART FAILURE. 11:30 AM

1999 ◽  
Vol 19 (5) ◽  
pp. 288
Author(s):  
M. Resnik ◽  
M. Halac ◽  
S. Thal ◽  
M. Bianconi ◽  
L. Saavedra Ruiz ◽  
...  
Keyword(s):  
Heart Failure ◽  
Chronic Heart Failure ◽  
Break Point ◽  
Double Product

Anaerobic threshold alterations caused by endurance training in middle-aged men

1979 ◽  
Vol 46 (6) ◽  
pp. 1039-1046 ◽  
Author(s):  
J. A. Davis ◽  
M. H. Frank ◽  
B. J. Whipp ◽  
K. Wasserman
Keyword(s):  
Endurance Training ◽  
Anaerobic Threshold ◽  
Minute Ventilation ◽  
Correlation Coefficients ◽  
Cycle Ergometer ◽  
Work Rate ◽  
Middle Aged ◽  
Co2 Output ◽  
Before And After ◽  
Cycle Endurance

Nine previously sedentary middle-aged males underwent cycle endurance training 45 min/day for 9 wk with an average attendance of 4.1 days/wk. Seven males served as controls. Before and after the training period, the subjects performed three cycle ergometer tests. Work rate was incremented by 15 W/min, to the limit of the subjects' tolerance, in the first two tests; the third test consisted of contant-load cycling at an O2 uptake (VO2) just below the pretraining anaerobic threshold (AT). After training, the AT increased significantly by 44%, expressed as absolute VO2, and by 15%, expressed relative to VO2 max. Significant increases were also noted in VO2max (25%), maximal minute ventilation (19%), and maximal work rate (28%). The test-retest correlation coefficients for the AT (%VO2max) were 0.91, pre- and posttraining. Training did not alter steady-state VO2 during the submaximal exercise test whereas significant decreases occurred in CO2 output, VE, respiratory quotient, and VE/VO2. No changes occurred in the control subjects during this period. These results demonstrate that the AT is profoundly influenced by endurance training in previously sedentary middle-aged males.

Seasonal Variation of V˙O2max and the V˙O2-Work Rate Relationship in Elite Alpine Skiers

2009 ◽  
Vol 41 (11) ◽  
pp. 2084-2089 ◽  
Author(s):  
MICAH A. GROSS ◽  
FABIO A. BREIL ◽  
ANDREA D. LEHMANN ◽  
HANS HOPPELER ◽  
MICHAEL VOGT
Keyword(s):  
Seasonal Variation ◽  
Work Rate ◽  
Rate Relationship ◽  
Alpine Skiers

RELIABILITY OF THE DOUBLE PRODUCT BREAK POINT.

1999 ◽  
Vol 31 (Supplement) ◽  
pp. S253
Author(s):  
T. A. Hargens ◽  
L. A. Kaminsky ◽  
M. H. Whaley ◽  
P. H. Brubaker ◽  
H. Tanaka
Keyword(s):  
Break Point ◽  
Double Product
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