Effects of erythropoietin administration on cerebral metabolism and exercise capacity in men

2010 ◽  
Vol 109 (2) ◽  
pp. 476-483 ◽  
Author(s):  
P. Rasmussen ◽  
E. M. Foged ◽  
R. Krogh-Madsen ◽  
J. Nielsen ◽  
T. R. Nielsen ◽  
...  
Keyword(s):  
Exercise Capacity ◽  
Oxygen Delivery ◽  
Perceived Exertion ◽  
Cerebral Metabolism ◽  
Central Fatigue ◽  
Voluntary Activation ◽  
High Dose ◽  
Ratings Of Perceived Exertion ◽  
Human Erythropoietin ◽  
Double Blinded

Recombinant human erythropoietin (EPO) increases exercise capacity by stimulating erythropoiesis and subsequently enhancing oxygen delivery to the working muscles. In a large dose, EPO crosses the BBB and may reduce central fatigue and improve cognition. In turn, this would augment exercise capacity independent of erythropoiesis. To test this hypothesis, 15 healthy young men (18–34 years old, 74 ± 7 kg) received either 3 days of high-dose (30,000 IU/day; n = 7) double-blinded placebo controlled or 3 mo of low-dose (5,000 IU/wk; n = 8) counter-balanced open but controlled administration of EPO. We recorded exercise capacity, transcranial ultrasonography-derived middle cerebral artery blood velocity, and arterial-internal jugular venous concentration differences of glucose and lactate. In addition, cognitive function, ratings of perceived exertion, ventilation, and voluntary activation by transcranial magnetic stimulation-induced twitch force were evaluated. Although EPO in a high dose increased cerebrospinal fluid EPO concentration ∼20-fold and affected ventilation and cerebral glucose and lactate metabolism ( P < 0.05), 3 days of high-dose EPO administration had no effect on cognition, voluntary activation, or exercise capacity, but ratings of perceived exertion increased ( P < 0.05). We confirmed that 3 mo of administration of EPO increases exercise capacity, but the improvement could not be accounted for by other mechanisms than enhanced oxygen delivery. In conclusion, EPO does not attenuate central fatigue or change cognitive performance strategy, suggesting that EPO enhances exercise capacity exclusively by increased oxygen delivery to the working muscles.

Exercising muscle mass influences neuromuscular, cardiorespiratory, and perceptual responses during and following ramp incremental cycling to task failure

2021 ◽  
Author(s):  
Jenny Zhang ◽  
Danilo Iannetta ◽  
Mohammed Alzeeby ◽  
Martin J. MacInnis ◽  
Saied Jalal Aboodarda
Keyword(s):  
Muscle Mass ◽  
Perceived Exertion ◽  
Central Fatigue ◽  
Exercise Duration ◽  
Peak Oxygen Uptake ◽  
Voluntary Contraction ◽  
Voluntary Activation ◽  
Peak Power Output ◽  
Task Failure ◽  
Single Twitch

Neuromuscular (NM), cardiorespiratory, and perceptual responses to maximal graded exercise using different amounts of active muscle mass remain unclear. We hypothesized that during dynamic exercise, peripheral NM fatigue (declined twitch force) and muscle pain would be greater using smaller muscle mass, whereas central fatigue (declined voluntary activation) and ventilatory variables would be greater using larger muscle mass. Twelve males (29.8±4.7 years) performed two cycling ramp incremental tests until task failure: (i) single-leg (SL) with 10 W·min-1ramp, and (ii) double-leg (DL) with 20 W·min-1ramp. NM fatigue was assessed at baseline, task failure (post), then after 1, 4, and 8 min of recovery. Cardiorespiratory and perceptual variables (i.e., ratings of perceived exertion (RPE), fatigue, pain, dyspnea) were measured throughout cycling. Exercise duration was similar between sessions (SL: 857.7±263.6; DL: 855.0±218.8 s; p=0.923) and higher absolute peak power output was attained in DL (SL: 163.2±43.8; DL: 307.0±72.0 W; p<0.001). While central fatigue did not differ between conditions (SL: -6.6±6.5%; DL: -3.5±4.8%; p=0.091), maximal voluntary contraction (SL: -41.6±10.9%; DL: -33.7±8.5%; p=0.032) and single twitch forces (SL: -59.4±18.8%; DL: -46.2±16.2%; p=0.003) declined more following SL. DL elicited higher peak oxygen uptake (SL: 42.1±10.0; DL:50.3±9.3 mL·kg-1·min-1; p<0.001), ventilation (SL: 137.1±38.1; DL: 171.5±33.2 L·min-1; p<0.001), and heart rate (SL: 167±21; DL: 187±8 bpm; p=0.005). Dyspnea (p=0.025) was higher in DL; however, RPE (p=0.005) and pain (p<0.001) were higher in SL. These results suggest that interplay between NM, cardiorespiratory, and perceptual determinants of exercise performance during incremental cycling to task failure are muscle mass-dependent.

scholarly journals Effects of two different doses of carbohydrate ingestion on taekwondo-related performance during a simulated tournament

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Alireza Naderi ◽  
Mohammad Hossein Samanipour ◽  
Amir Sarshin ◽  
Scott C. Forbes ◽  
Majid S. Koozehchian ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Perceived Exertion ◽  
Low Dose ◽  
High Dose ◽  
Ratings Of Perceived Exertion ◽  
Three Solutions ◽  
Double Blind ◽  
Carbohydrate Ingestion ◽  
Gastrointestinal Discomfort ◽  
Different Doses

Abstract Background Carbohydrate (CHO) ingestion enhances exercise performance; however, the efficacy of CHO intake on repeated bouts of exercise simulating a taekwondo tournament is unknown. Therefore, the purpose was to compare the effects of two different doses of CHO on a sports-specific kicking test during a simulated taekwondo tournament compared to placebo (PLA). Methods In a double-blind, randomized-placebo controlled, cross-over trial, eleven junior male professional taekwondo athletes (age: 16 ± 0.8 years, body mass: 55.3 ± 7.3 kg) ingested one of three solutions: (i) high dose (C45): 45 g of CHO (60 g∙h− 1), (ii) low dose (C22.5): 22.5 g of CHO (30 g∙h− 1; both solutions containing 2:1 glucose:fructose), or a PLA immediately following each kicking test. The kicking test was repeated 5 times, separated by 45 mins of rest, simulating a typical taekwondo competition day. Ratings of perceived exertion (RPE) and gastrointestinal discomfort (GI) scores were collected immediately after, and blood glucose before each test. Results The results revealed that C45 and C22.5 did not improve total, successful, or percentage of successful kicks compared to PLA (p > 0.05). Blood glucose was significantly higher following both CHO conditions compared with PLA across all five tests (p < 0.05). There were no differences between treatments or across tests for RPE (p > 0.05). Conclusion CHO intake, independent of the dose, did not alter taekwondo kick performance during a simulated taekwondo tournament.

Hydrogen Rich Water Improved Ventilatory, Perceptual and Lactate Responses to Exercise

2019 ◽  
Vol 40 (14) ◽  
pp. 879-885 ◽  
Author(s):  
Michal Botek ◽  
Jakub Krejčí ◽  
Andrew J. McKune ◽  
Barbora Sládečková ◽  
Nenad Naumovski
Keyword(s):  
Blood Lactate ◽  
Perceived Exertion ◽  
Ratings Of Perceived Exertion ◽  
Exercise Protocol ◽  
Warm Up ◽  
Ventilatory Equivalent ◽  
Lower Blood ◽  
And Performance ◽  
Exercise Induced ◽  
Double Blinded

AbstractThe potential anti-fatigue and performance benefits of hydrogen rich water (HRW) have resulted in increased research interest over the past 5 years. The aim of this study was to assess physiological and perceptual responses to an incremental exercise protocol after administration of 600 ml HRW within 30 min before exercise. This randomized, double blinded placebo-controlled cross over study included twelve healthy males aged 27.1±4.9 years. The exercise protocol consisted of a 10 min warm-up at 1.0 W.kg−1, followed by 8 min at 2.0, 3.0, and 4.0 W.kg−1, respectively. Cardio-respiratory variables, lactate and ratings of perceived exertion (RPE) were assessed in the last minute of each step. A significantly lower blood lactate was found with HRW (4.0±1.6 and 8.9±2.2 mmol.l−1) compared to Placebo (5.1±1.9 and 10.6±3.0 mmol.l−1) at 3.0, and 4.0 W.kg−1, respectively. Ventilatory equivalent for oxygen and RPE exhibited significantly lower values with HRW (32.3±7.2, and 17.8±1.2 points, respectively) compared to Placebo (35.0±8.4, and 18.5±0.8 points, respectively) at 4 W.kg−1. To conclude, acute pre-exercise supplementation with HRW reduced blood lactate at higher exercise intensities, improved exercise-induced perception of effort, and ventilatory efficiency.

Physiologic responses to a thermogenic nutritional supplement at rest, during low-intensity exercise, and during recovery from exercise in college-aged women

2013 ◽  
Vol 38 (9) ◽  
pp. 988-995 ◽  
Author(s):  
Haley C. Bergstrom ◽  
Terry J. Housh ◽  
Daniel A. Traylor ◽  
Robert W. Lewis ◽  
Nathaniel D.M. Jenkins ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Perceived Exertion ◽  
Resting Energy Expenditure ◽  
Nutritional Supplement ◽  
Ratings Of Perceived Exertion ◽  
Perception Of Effort ◽  
Postexercise Recovery ◽  
Double Blinded ◽  
Low Intensity Exercise ◽  
Physiologic Responses

This study examined acute physiologic responses to a thermogenic nutritional supplement at rest, during exercise, and during recovery from exercise in women. Twelve women (mean ± SD age, 22.9 ± 3.1 years) were recruited for this randomized, double-blinded, placebo-controlled, crossover study. Each testing session consisted of 4 phases: 30 min of presupplementation resting, followed by the ingestion of the placebo or thermogenic nutritional supplement; 50 min of postsupplementation resting; 60 min of walking (at 3.2–4.8 km·h−1); and 50 min of postexercise resting. Energy expenditure (EE), oxygen consumption, respiratory exchange ratio (RER), oxygen (O2) pulse, and heart rate (HR) values were recorded during all 4 phases. Systolic (SBP) and diastolic (DBP) blood pressure were recorded during the rest, postsupplementation, and postexercise recovery phases; ratings of perceived exertion (RPE) were recorded only during exercise. There were no significant differences for EE, oxygen consumption, O2 pulse, HR, SBP, or DBP between the supplement and placebo during the presupplementation resting or postsupplementation phases. The RER, however, was higher with the supplement at 30 min postsupplementation. During exercise, EE and O2 pulse were 3%–6% greater with the supplement than placebo; there were no significant differences in RPE. Postexercise, EE, oxygen consumption, and DBP were 3%–7% greater with the supplement than placebo. These findings suggest that a thermogenic nutritional supplement, when combined with exercise, increases metabolic rate but has no effect on the perception of effort and results in only minimal changes in cardiovascular function.

Effect of exercise modality on ratings of perceived exertion at various lactate concentrations

1991 ◽  
Vol 23 (1) ◽  
pp. 88???92 ◽  
Author(s):  
R. K. HETZLER ◽  
R. L. SEIP ◽  
S. H. BOUTCHER ◽  
E. PIERCE ◽  
D. SNEAD ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Ratings Of Perceived Exertion ◽  
Exercise Modality

Psychophysical and physiological comparison of squat and semi-squat lifting by young males

1999 ◽  
Vol 2 (1) ◽  
pp. 17-26
Author(s):  
Leon Straker ◽  
Carol Cain
Keyword(s):  
Heart Rate ◽  
Perceived Exertion ◽  
Ratings Of Perceived Exertion ◽  
Lower Heart Rate ◽  
Young Males ◽  
Squat Lifting

A comparison between semi-squat and squat techniques was made for floor to knuckle height lifting using maximum acceptable weight (MAW), ratings of perceived exertion (RPE) and heart rate. Semi-squat lifting resulted in greater MAW with lower RPE and lower heart rate compared to squat lifting. Discomfort was most commonly reported in knees/quadriceps with squat lifting. Twelve of the 13 subjects preferred the semi-squat technique. The results provide evidence that the semi-squat technique may have benefits over the squat technique for lifting a medium sized box from floor to knuckle height.

scholarly journals Functional Translation of Exercise Responses from Exercise Testing to Exercise Training: The Test of a Model

2021 ◽  
Vol 6 (3) ◽  
pp. 66
Author(s):  
Tristan Tyrrell ◽  
Jessica Pavlock ◽  
Susan Bramwell ◽  
Cristina Cortis ◽  
Scott T. Doberstein ◽  
...  
Keyword(s):  
Exercise Testing ◽  
Exercise Test ◽  
Perceived Exertion ◽  
Exercise Prescription ◽  
Test Results ◽  
Training Intensity ◽  
Ratings Of Perceived Exertion ◽  
Metabolic Equivalents ◽  
Cardiovascular Drift ◽  
And Training

Exercise prescription based on exercise test results is complicated by the need to downregulate the absolute training intensity to account for cardiovascular drift in order to achieve a desired internal training load. We tested a recently developed generalized model to perform this downregulation using metabolic equivalents (METs) during exercise testing and training. A total of 20 healthy volunteers performed an exercise test to define the METs at 60, 70, and 80% of the heart rate (HR) reserve and then performed randomly ordered 30 min training bouts at absolute intensities predicted by the model to achieve these levels of training intensity. The training HR at 60 and 70% HR reserve, but not 80%, was significantly less than predicted from the exercise test, although the differences were small. None of the ratings of perceived exertion (RPE) values during training were significantly different than predicted. There was a strong overall correlation between predicted and observed HR (r = 0.88) and RPE (r = 0.52), with 92% of HR values within ±10 bpm and 74% of RPE values within ±1 au. We conclude that the generalized functional translation model is generally adequate to allow the generation of early absolute training loads that lead to desired internal training loads.

scholarly journals Special Training of Inspiratory Muscles in Fitness Activities and Exercise Capacity in Young Women

2017 ◽  
Vol 18 (3) ◽  
Author(s):  
Viktor Mishchenko ◽  
Stanislaw Sawczyn ◽  
Agnieszka Cybulska ◽  
Marcin Pasek
Keyword(s):  
Oxygen Uptake ◽  
Exercise Capacity ◽  
Young Women ◽  
Vital Capacity ◽  
Perceived Exertion ◽  
Minute Ventilation ◽  
Work Capacity ◽  
Control Group ◽  
Inspiratory Muscles ◽  
Fitness Training

AbstractPurpose. The aim of the study was to determine if an 8-week-long endurance fitness training with elastic belts would increase the strength-endurance of the inspiratory muscles and lung function characteristics, and to assess whether these changes were consistent with an increase in aerobic power and exercise capacity in healthy young women. Methods. Twenty-two females aged 20-25 years were randomly allocated into 2 groups. The experimental group preformed 8-week-long exercises on stationary bikes with an elastic belt on the lower part of the chest. The control group underwent the same workout, without elastic belts. Vital capacity, forced vital capacity, maximal voluntary ventilation, maximal inspiratory and expiratory pressure, sustained maximal inspiratory pressure, physical activity status, and perceived exertion scores were measured. In the incremental exercise test, work capacity and maximal oxygen uptake were assessed. Tidal volume, minute ventilation (VE), oxygen uptake (VO

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