Effects of exercise at the anaerobic threshold on respiratory quotient in young male subjects

2021 ◽  
pp. 9-12
Keyword(s):  
Anaerobic Threshold ◽  
Exercise Test ◽  
Respiratory Quotient ◽  
Young Male ◽  
Work Load ◽  
Constant Load ◽  
Exercise Time ◽  
Oxidation Ratio ◽  
Male Subjects ◽  
Constant Load Exercise

Aim: Exercise has great influence on increasing metabolic system functions. The work load corresponded to anaerobic threshold provide optimal aerobic strain for metabolic activity in exercising muscle. In the present study we intended to evaluate body substrate oxidation ratio during constant load exercise test at the intensity of anaerobic threshold in healthy young male subjects. Material and Method: Total of 15 male performed an incremental ramp exercise test to estimate anaerobic threshold. Standard V-slope method used to estimate anaerobic threshold. Then each subject performed a constant load exercise test for a 30 min period with a work load corresponded to their anaerobic threshold. Respiratory quotient (RQ) used to evaluate substrate oxidations during exercise. Anova test used to evaluate significance of data obtained every 5 minutes of constant load exercise. Results: The subjects’ anaerobic threshold occurred at approximately 63% of their maximal exercise capacity. RQ varied markedly among the subjects but as a mean value, but it systematically decreased with increasing exercise time. Body mass index and exercise time has great importance on fat and carbohydrate oxidation ratio. Conclusion: Exercise intensity at the anaerobic threshold provides meaningfully fat oxidation and could be acceptable in subjects with high body fat mass.

scholarly journals The respiratory and metabolic responses for determinants of exercise endurance time in constant-load exercise test in healthy adult volunteers, prospective cross-sectional design

2020 ◽  
Author(s):  
Shohei Kawachi ◽  
Keisaku Fujimoto
Keyword(s):  
Anaerobic Threshold ◽  
Exercise Test ◽  
Minute Ventilation ◽  
Maximum Load ◽  
Constant Load ◽  
Metabolic Responses ◽  
Peak Exercise ◽  
Cross Sectional ◽  
Endurance Time ◽  
Constant Load Exercise

Abstract Although constant-load exercise test is performed at approximately 80% of maximum load determined based on individual exercise capacity of incremental-load exercise test, some subjects cannot maintain exercising in constant-load exercise test. We assumed that the metabolic responses difference between those who are and are not able to maintain exercising in only constant-load exercise. Therefore, present study was performed to elucidate the metabolic responses for determinants of endurance time in constant-load exercise test. Twenty-seven healthy volunteers performed constant-load exercise test at 80% of maximum load determined by incremental-load exercise test. Subjects were separated into those who were and were not able to complete 20 minutes of constant-load exercise test. The metabolic indexes were compared between the two groups. The not-completed group showed significantly higher respiratory exchange ratio (RER) as anaerobic threshold and minimum minute ventilation/carbon dioxide production (VE/VCO2) as ventilatory inefficiency at peak exercise only in constant-load exercise test (P < 0.05). It was suggested that the respiratory and metabolic responses for determinants of endurance time in constant-load exercise test were exercise beyond anaerobic threshold and the increase in CO2 output due to ventilatory inefficiency related to a reduced skeletal muscle in healthy adults.

scholarly journals Comparison of constant load exercise intensity for verification of maximal oxygen uptake following a graded exercise test in older adults

2021 ◽  
Vol 9 (18) ◽  
Author(s):  
Ian R. Villanueva ◽  
John C. Campbell ◽  
Serena M. Medina ◽  
Theresa M. Jorgensen ◽  
Shannon L. Wilson ◽  
...  
Keyword(s):  
Older Adults ◽  
Oxygen Uptake ◽  
Exercise Intensity ◽  
Exercise Test ◽  
Maximal Oxygen Uptake ◽  
Constant Load ◽  
Graded Exercise Test ◽  
Graded Exercise ◽  
Constant Load Exercise

scholarly journals Differences in cardiorespiratory responses of young and senior male endurance athletes to maximal graded exercise test

2020 ◽  
Vol 107 (3) ◽  
pp. 444-454
Author(s):  
M. Michalis ◽  
K.J. Finn ◽  
R. Podstawski ◽  
S. Gabnai ◽  
Á. Koller ◽  
...  
Keyword(s):  
Anaerobic Threshold ◽  
Exercise Test ◽  
Power Output ◽  
Submaximal Exercise ◽  
Incremental Exercise ◽  
Maximal Heart Rate ◽  
Young Athletes ◽  
Exercise Economy ◽  
Significant Difference ◽  
Male Subjects

AbstractWithin recent years the popularity of sportive activities amongst older people, particularly competitive activities within certain age groups has increased. The purpose of this study was to assess the differences in the cardiorespiratory output at anaerobic threshold and at maximal power, output during an incremental exercise, among senior and young athletes. Ten elderly male subjects [mean (SD) age: 68.45 ± 9.32 years] and eight young male subjects [mean (SD) age: 25.87 ± 5.87 years] performed an incremental exercise test on a treadmill ergometer. No significant differences in body size were evident; however, the differences between the groups for peak power (451.62 ± 49 vs. 172.4 ± 32.2 W), aerobic capacity (57.97 ± 7.5 vs. 40.36 ± 8.6 mL kg−1 min−1), maximal heart rate (190.87 ± 9.2 vs. 158.5 ± 9.1 beats min−1), peak blood lactate (11 ± 1.7 vs. 7.3 ± 1.4 mmol L−1), and % VO2max at ventilatory thresholds (93.18 ± 4.3 vs. 79.29 ± 9.9%) were significantly lower in the senior athletes. The power output at anaerobic threshold was also higher (392 ± 48 vs. 151 ± 23 W) in the young athletes, explaining the significant difference in terms of performance between these groups. We have observed an evident deterioration in some of the cardiovascular parameters; however, the submaximal exercise economy seems to be preserved with aging. Exercise economy (i.e. metabolic cost of sustained submaximal exercise) was not different considerably with age in endurance-trained adults.

Prior exercise delays the onset of acidosis during incremental exercise

2007 ◽  
Vol 102 (5) ◽  
pp. 1799-1805 ◽  
Author(s):  
Graydon H. Raymer ◽  
Sean C. Forbes ◽  
John M. Kowalchuk ◽  
R. Terry Thompson ◽  
Greg D. Marsh
Keyword(s):  
Intracellular Ph ◽  
Exercise Test ◽  
Exercise Performance ◽  
Metabolic Response ◽  
Constant Load ◽  
Incremental Exercise ◽  
Moderate Intensity ◽  
Intracellular Acidosis ◽  
Incremental Exercise Test ◽  
Constant Load Exercise

The effects of prior moderate- and prior heavy-intensity exercise on the subsequent metabolic response to incremental exercise were examined. Healthy, young adult subjects ( n = 8) performed three randomized plantar-flexion exercise tests: 1) an incremental exercise test (∼0.6 W/min) to volitional fatigue (Ramp); 2) Ramp preceded by 6 min of moderate-intensity, constant-load exercise below the intracellular pH threshold (pHT; Mod-Ramp); and 3) Ramp preceded by 6 min of heavy-intensity, constant-load exercise above pHT (Hvy-Ramp); the constant-load and incremental exercise periods were separated by 6 min of rest. 31P-magnetic resonance spectroscopy was used to continuously monitor intracellular pH, phosphocreatine concentration ([PCr]), and inorganic phosphate concentration ([Pi]). No differences in exercise performance or the metabolic response to exercise were observed between Ramp and Mod-Ramp. However, compared with Ramp, a 14% (SD 10) increase ( P < 0.01) in peak power output (PPO) was observed in Hvy-Ramp. The improved exercise performance in Hvy-Ramp was accompanied by a delayed ( P = 0.01) onset of intracellular acidosis [Hvy-Ramp 60.4% PPO (SD 11.7) vs. Ramp 45.8% PPO (SD 9.4)] and a delayed ( P < 0.01) onset of rapid increases in [Pi]/[PCr] [Hvy-Ramp 61.5% PPO (SD 12.0) vs. Ramp 45.1% PPO (SD 9.1)]. In conclusion, prior heavy-intensity exercise delayed the onset of intracellular acidosis and enhanced exercise performance during a subsequent incremental exercise test.

Interval Training Intensity Affects Energy Intake Compensation in Obese Men

2014 ◽  
Vol 24 (6) ◽  
pp. 595-604 ◽  
Author(s):  
Shaea A. Alkahtani ◽  
Nuala M. Byrne ◽  
Andrew P. Hills ◽  
Neil A. King
Keyword(s):  
Energy Intake ◽  
Exercise Test ◽  
Food Preferences ◽  
Interval Training ◽  
Constant Load ◽  
Two Dimensions ◽  
The Difference ◽  
High Intensity Interval ◽  
Desire To Eat ◽  
Constant Load Exercise

Purpose:Compensatory responses may attenuate the effectiveness of exercise training in weight management. The aim of this study was to compare the effect of moderate- and high-intensity interval training on eating behavior compensation.Methods:Using a crossover design, 10 overweight and obese men participated in 4-week moderate (MIIT) and high (HIIT) intensity interval training. MIIT consisted of 5-min cycling stages at ±20% of mechanical work at 45%VO2peak, and HIIT consisted of alternate 30-s work at 90%VO2peak and 30-s rests, for 30 to 45 min. Assessments included a constant-load exercise test at 45%VO2peak for 45 min followed by 60-min recovery. Appetite sensations were measured during the exercise test using a Visual Analog Scale. Food preferences (liking and wanting) were assessed using a computer-based paradigm, and this paradigm uses 20 photographic food stimuli varying along two dimensions, fat (high or low) and taste (sweet or nonsweet). An ad libitum test meal was provided after the constant-load exercise test.Results:Exerciseinduced hunger and desire to eat decreased after HIIT, and the difference between MIIT and HIIT in desire to eat approached significance (p = .07). Exercise-induced liking for high-fat nonsweet food tended to increase after MIIT and decreased after HIIT (p = .09). Fat intake decreased by 16% after HIIT, and increased by 38% after MIIT, with the difference between MIIT and HIIT approaching significance (p = .07).Conclusions:This study provides evidence that energy intake compensation differs between MIIT and HIIT.

scholarly journals The VO2-on Kinetics in Constant Load Exercise Sub-Anaerobic Threshold Reflects Endothelial Function and Dysfunction in Muscle Microcirculation

2015 ◽  
pp. 807-819
Author(s):  
D. MAIONE ◽  
A. F. G. CICERO ◽  
S. BACCHELLI ◽  
E. R. COSENTINO ◽  
D. DEGLI ESPOSTI ◽  
...  
Keyword(s):  
Endothelial Dysfunction ◽  
Endothelial Function ◽  
Anaerobic Threshold ◽  
Nyha Class ◽  
Constant Load ◽  
Cycle Ergometer ◽  
Phase 3 ◽  
Heart Patients ◽  
Highly Sensitive ◽  
Constant Load Exercise

To propose a test to evaluate endothelial function, based on VO2 on-transition kinetics in sub-anaerobic threshold (AT) constant load exercise, we tested healthy subjects and patients with ischemic-hypertensive cardiopathy by two cardiopulmonary tests on a cycle ergometer endowed with an electric motor to overcome initial inertia: a pre-test and, after at least 24 h, one 6 min constant load exercise at 90 % AT. We measured net phase 3 VO2-on kinetics and, by phase 2 time constant (τ), valued endothelial dysfunction. We found shorter τ in repeated tests, shorter time between first and second test, by persisting endothelium-dependent arteriolar vasodilatation and/or several other mechanisms. Reducing load to 80 % and 90 % AT did not produce significant changes in τ of healthy volunteers, while in heart patients an AT load of 70 %, compared to 80 % AT, shortened τ (=4.38±1.65 s, p=0.013). In heart patients, no correlation was found between NYHA class, ejection fraction (EF), and the two variables derived from incremental cycle cardio-pulmonary exercise, as well as between EF and τ; while NYHA class groups were well correlated with τ duration (r=0.92, p=0.0001). Doxazosin and tadalafil also significantly reduced τ. In conclusion, the O2 consumption kinetics during the on-transition of constant load exercise below the anaerobic threshold are highly sensitive to endothelial function in muscular microcirculation, and constitute a marker for the evaluation of endothelial dysfunction.

Ultrastructural Study of Human Testicular Biopsies in Infertility

1976 ◽  
Vol 34 ◽  
pp. 156-157
Author(s):  
Shirley Siew ◽  
Philip Troen ◽  
Howard R. Nankin
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Basement Membrane ◽  
Leydig Cells ◽  
Clinical Evidence ◽  
Young Male ◽  
Germinal Epithelium ◽  
Transmission Electron ◽  
Age Range ◽  
Male Subjects

Testicular biopsies were obtained from six young male subjects (age range 24-33) who complained of infertility and who had clinical evidence of oligospermia. This was confirmed on histological examination which showed a broad spectrum from profound hypospermatogenesis to relatively normal appearing germinal epithelium. Thickening of the tubular walls was noted in half of the cases and slight peritubular fibrosis in one. The Leydig cells were reported as normal or unremarkable.Transmission electron microscopy showed that the thickening of the supporting tissue of the germinal epithelium was caused more by an increase in the thickness of the layers of the lamina propria than of the tubular wall itself. The changes in the basement membrane of the tubular wall consisted mostly of a greater degree of infolding into the tubule and some reduplication which gave rise to a multilayered appearance.

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