The effects of exercise intensity and duration on the relationship between the slow component of V̇O 2 and peripheral fatigue

2022 ◽  
Author(s):  
Rafael de Almeida Azevedo ◽  
Daniel A. Keir ◽  
Jonas Forot ◽  
Danilo Iannetta ◽  
Guillaume Y. Millet ◽  
...  
Keyword(s):  
Exercise Intensity ◽  
Slow Component ◽  
Peripheral Fatigue ◽  
The Relationship

Relationship of potassium ions and blood lactate to ventilation during exercise

2010 ◽  
Vol 35 (5) ◽  
pp. 691-698
Author(s):  
Robert G. McMurray ◽  
Matthew S. Tenan
Keyword(s):  
Blood Lactate ◽  
Exercise Intensity ◽  
Minute Ventilation ◽  
Potassium Ions ◽  
Ventilatory Control ◽  
Volitional Fatigue ◽  
Relationship Of ◽  
Glycogen Stores ◽  
The Relationship ◽  
Recent Attention

Ventilatory control during exercise is a complex network of neural and humoral signals. One humoral input that has received little recent attention in the exercise literature is potassium ions [K+]. The purpose of this study was to examine the relationship between [K+] and ventilation during an incremental cycle test and to determine if the relationship between [K+] and ventilation differs when blood lactate [lac–] is manipulated. Eight experienced triathletes (4 of each sex) completed 2 incremental, progressive (5-min stages) cycle tests to volitional fatigue: 1 with normal glycogen stores and 1 with reduced glycogen. Minute ventilation was measured during the final minute of each stage, and blood [lac–] and [K+] were measured at the end of each exercise stage. Minute ventilation and [K+] increased with exercise intensity and were similar between trials (p > 0.5), despite lower [lac–] during the reduced-glycogen trial. The concordance correlations (Rc) between [lac–] and minute ventilation were stronger for both trials (Rc = ~0.88–0.96), but the slopes of the relationships were different than the relationships between [K+] and minute ventilation (Rc = ~0.76–0.89). The slope of the relationship between [lac–] and minute ventilation was not as steep during the reduced-glycogen trial, compared with the normal trial (p = 0.002). Conversely, the slope of the relationships between [K+] and minute ventilation did not change between trials (p = 0.454). The consistent relationship of minute ventilation and blood [K+] during exercise suggests a role for this ion in the control of ventilation during exercise. Conversely, the inconsistent relationship between blood lactate and ventilation brings into question the importance of the relationship between lactate and ventilation during exercise.

scholarly journals Manifestations of muscle fatigue in baseball pitchers: a systematic review

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7390 ◽  
Author(s):  
Richard Birfer ◽  
Michael WL Sonne ◽  
Michael WR Holmes
Keyword(s):  
Injury Risk ◽  
Relevant Literature ◽  
Peripheral Fatigue ◽  
Future Research ◽  
Cochrane Database ◽  
Rest Time ◽  
Baseball Pitchers ◽  
And Performance ◽  
Conference Papers ◽  
The Relationship

Background Fatigue in baseball pitchers is a process linked to lowered physical and mental performance, injury, and changes in kinematics. Numerous studies have associated fatigue with overuse, high ball velocities, lack of rest time, poor mechanics, and degree of self-satisfaction. The aim of this study was to systematically review the literature to identify a theoretical framework for the relationship between outcomes and the manifestation of fatigue on baseball pitching. The synthesized data may identify areas requiring further research. Methodology This protocol was registered with PROSPERO (ID: CRD42018114194). SPORTDiscus, Medline, PubMed, Cochrane Database of Systematic Reviews, and Google Scholar were searched, using keywords such as fatigue in pitchers and changes in kinematics (e.g., pitching mechanics, valgus elbow torque), performance (e.g., pitch count, pitch type), and injury (e.g., pain, elbow, and shoulder soreness). Three reviewers independently screened the articles, selected relevant literature based on abstract eligibility, and assessed the methods described therein for final inclusion. Results A total of 31,860 articles were screened for eligibility and 25 articles were included for the review. The selected articles included epidemiological, longitudinal, experimental, conference papers, and crossover laboratory studies. Evidence extracted from the 25 studies demonstrates a relationship between fatigue in baseball pitching, and three overarching outcomes: changes in kinematics, a decrease in performance, and an increase in injury risk. Conclusions Findings show that a co-dependence between changes in kinematics and a decrease in performance, which stems from central and peripheral fatigue, is a contributing factor of injury in baseball pitchers. A large percentage of baseball pitchers exhibit pain or soreness in either their elbow or shoulder, or both at some point in a season. Initially, kinematic changes occur that could maintain performance, but may increase joint and tissue loading. Performance decreased with elevated pitch counts and innings thrown, and pitching further into games or the season. Evidence was found to be consistent across all studies; however, more work is needed in the area of fatigue as an injury mechanism during pitching. With a proof of concept established, the prevention of negative outcomes associated with fatigue must be the focus of future research and performance should not be the only criteria.

Plasma free and sulfoconjugated catecholamine responses to varying exercise intensity

1987 ◽  
Vol 63 (2) ◽  
pp. 654-658 ◽  
Author(s):  
M. S. Sothmann ◽  
A. B. Gustafson ◽  
M. Chandler
Keyword(s):  
Oxygen Consumption ◽  
Exercise Intensity ◽  
High Intensity ◽  
Maximal Oxygen Consumption ◽  
High Intensity Exercise ◽  
The Relationship ◽  
Circulating Levels

Plasma free catecholamines rise during exercise, but sulfoconjugated catecholamines reportedly fall. This study examined the relationship between exercise intensity and circulating levels of sulfoconjugated norepinephrine, epinephrine, and dopamine. Seven exercise-trained men biked at approximately 30, 60, and 90% of their individual maximal oxygen consumption (VO2max) for 8 min. The 90% VO2max period resulted in significantly increased plasma free norepinephrine (rest, 219 +/- 85; exercise, 2,738 +/- 1,149 pg/ml; P less than or equal to 0.01) and epinephrine (rest, 49 +/- 49; exercise, 555 +/- 516 pg/ml; P less than or equal to 0.05). These changes were accompanied by consistent increases in sulfoconjugated norepinephrine at both the 60% (rest, 852 +/- 292; exercise, 1,431 +/- 639; P less than or equal to 0.05) and 90% (rest, 859 +/- 311; exercise, 2,223 +/- 1,015; P less than or equal to 0.05) VO2max periods. Plasma sulfoconjugated epinephrine and dopamine displayed erratic changes at the three exercise intensities. These findings suggest that sulfoconjugated norepinephrine rises during high-intensity exercise.

Effect of acute hypoxia on vasopressin release and intravascular fluid during dynamic exercise in humans

2000 ◽  
Vol 279 (1) ◽  
pp. R161-R168 ◽  
Author(s):  
Akira Takamata ◽  
Hiroshi Nose ◽  
Takashi Kinoshita ◽  
Munetaka Hirose ◽  
Toshiyuki Itoh ◽  
...  
Keyword(s):  
Exercise Intensity ◽  
Acute Hypoxia ◽  
Electrolyte Balance ◽  
Vasopressin Release ◽  
Fluid Movement ◽  
Hypotonic Fluid ◽  
Vascular Space ◽  
Relative Exercise Intensity ◽  
Graded Exercise ◽  
The Relationship

To test the hypothesis that acute hypoxia does not modify the relationship between plasma vasopressin concentration ([AVP]p) and plasma osmolality (Posmol) during exercise and that the increase in [AVP]p during exercise is due mainly to the exercise intensity-dependent increase in Posmol, we examined [AVP]p during a graded exercise in a hypoxic condition (13% O2, N2 balance) in seven healthy male subjects. A graded exercise in a normoxic condition on a separate day served as the control. Hypoxia reduced peak aerobic power (V˙o 2 peak) by 32.4 ± 2.7%. Blood samples obtained during rest and at around 25, 45, 65, 80, and 100% ofV˙o 2 peak of each of the respective conditions were used for analyses of intravascular water and electrolyte balance. The pattern of the changes in fluid and electrolyte balance in response to percentV˙o 2 peak was similar between the two conditions. Plasma volume decreased linearly as percentV˙o 2 peak increased while Posmol increased in a curvilinear fashion with a steep increase occurring at above ∼66%V˙o 2 peak. Above this relative exercise intensity, plasma sodium, potassium, and lactate concentrations also increased, whereas plasma bicarbonate concentration decreased. Thus transvascular fluid movement at above ∼66%V˙o 2 peak was due to the net efflux of hypotonic fluid out of the vascular space in both conditions. The relationship between [AVP]p and Posmol during exercise in response to relative exercise intensity was similar between the two conditions. The results indicate that acute mild hypoxia itself has no direct effect on vasopressin release, and it does not modify the relationship between [AVP]p and Posmol during exercise. The results also support the hypothesis that exercise-induced vasopressin release is primarily stimulated by increased Posmol produced by hypotonic fluid movement out of the vascular space in a relative exercise intensity-dependent manner.

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.

Sign in / Sign up

Export Citation Format

Share Document