scholarly journals The prefrontal oxygenation and ventilatory responses at start of one-legged cycling exercise have relation to central command

2016 ◽  
Vol 121 (5) ◽  
pp. 1115-1126 ◽  
Author(s):  
Ryota Asahara ◽  
Kanji Matsukawa ◽  
Kei Ishii ◽  
Nan Liang ◽  
Kana Endo
Keyword(s):  
Time Course ◽  
Perceived Exertion ◽  
Ventilatory Response ◽  
Minute Ventilation ◽  
Hemoglobin Concentration ◽  
Carbon Dioxide Tension ◽  
Rating Of Perceived Exertion ◽  
Subjective Rating ◽  
Central Command ◽  
Cycling Exercise

When performing exercise arbitrarily, activation of central command should start before the onset of exercise, but when exercise is forced to start with cue, activation of central command should be delayed. We examined whether the in-advance activation of central command influenced the ventilatory response and reflected in the prefrontal oxygenation, by comparing the responses during exercise with arbitrary and cued start. The breath-by-breath respiratory variables and the prefrontal oxygenated-hemoglobin concentration (Oxy-Hb) were measured during one-legged cycling. Minute ventilation (V̇e) at the onset of arbitrary one-legged cycling was augmented to a greater extent than cued cycling, while end-tidal carbon dioxide tension (ETco2) decreased irrespective of arbitrary or cued start. Symmetric increase in the bilateral prefrontal Oxy-Hb occurred before and at the onset of arbitrary one-legged cycling, whereas such an increase was absent with cued start. The time course and magnitude of the increased prefrontal oxygenation were not influenced by the extent of subjective rating of perceived exertion and were the same as those of the prefrontal oxygenation during two-legged cycling previously reported. Mental imagery or passive performance of the one-legged cycling increased V̇e and decreased ETco2. Neither intervention, however, augmented the prefrontal Oxy-Hb. The changes in ETco2 could not explain the prefrontal oxygenation response during voluntary or passive one-legged cycling. Taken together, it is likely that the in-advance activation of central command influenced the ventilatory response by enhancing minute ventilation at the onset of one-legged cycling exercise and reflected in the preexercise increase in the prefrontal oxygenation.

Acute Effects of Dietary Ginger on Quadriceps Muscle Pain during Moderate-Intensity Cycling Exercise

2008 ◽  
Vol 18 (6) ◽  
pp. 653-664 ◽  
Author(s):  
Christopher D. Black ◽  
Patrick J. O’Connor
Keyword(s):  
Muscle Pain ◽  
Time Course ◽  
Perceived Exertion ◽  
Quadriceps Muscle ◽  
Work Rate ◽  
Rating Of Perceived Exertion ◽  
Moderate Intensity ◽  
Double Blind ◽  
Similar Time ◽  
Cycling Exercise

Ginger has known hypoalgesic and anti-inflammatory properties. The effects of an oral dose of ginger on quadriceps muscle pain, rating of perceived exertion (RPE), and recovery of oxygen consumption were examined during and after moderateintensity cycling exercise. Twenty-five college-age participants ingested a 2-g dose of ginger or placebo in a double-blind, crossover design and 30 min later completed 30 min of cycling at 60% of VO2peak. Quadriceps muscle pain, RPE, work rate, heart rate (HR), and oxygen uptake (VO2) were recorded every 5 min during exercise, and HR and VO2 were recorded for 20 min after exercise. Compared with placebo, ginger had no clinically meaningful or statistically significant effect on perceptions of muscle pain, RPE, work rate, HR, or VO2 during exercise. Recovery of VO2 and HR after the 30-min exercise bout followed a similar time course in the ginger and placebo conditions. The results were consistent with related findings showing that ingesting a large dose of aspirin does not acutely alter quadriceps muscle pain during cycling, and this suggests that prostaglandins do not play a large role in this type of exercise-induced skeletal-muscle pain. Ginger consumption has also been shown to improve VO2 recovery in an equine exercise model, but these results show that this is not the case in humans.

scholarly journals Performance and Recovery of Well-Trained Younger and Older Athletes during Different HIIT Protocols

Sports ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 9
Author(s):  
Laura Hottenrott ◽  
Martin Möhle ◽  
Sarah Feichtinger ◽  
Sascha Ketelhut ◽  
Oliver Stoll ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Age Groups ◽  
Average Power ◽  
Lactate Concentration ◽  
Fat Free Mass ◽  
Rating Of Perceived Exertion ◽  
Subjective Rating ◽  
Maximal Heart Rate ◽  
Total Quality ◽  
Older Athletes

Due to physiological and morphological differences, younger and older athletes may recover differently from training loads. High-intensity interval training (HIIT) protocols are useful for studying the progression of recovery. It was the objective of this study to determine age differences in performance and recovery following different HIIT protocols. Methods: 12 younger (24.5 ± 3.7 years) and 12 older (47.3 ± 8.6 years) well-trained cyclists and triathletes took part in this study. Between the age groups there were no significant differences in relative peak power to fat-free mass, maximal heart rate (HR), training volume, and VO2max-percentiles (%). Participants performed different HIIT protocols consisting of 4 × 30 s Wingate tests with different active rest intervals (1, 3, or 10 min). Peak and average power, lactate, HR, respiratory exchange ratio (RER), subjective rating of perceived exertion (RPE), and recovery (Total Quality Recovery scale, TQR) were assessed. Results: During the different HIIT protocols, metabolic, cardiovascular, and subjective recovery were similar between the two groups. No significant differences were found in average lactate concentration, peak and average power, fatigue (%), %HRmax, RER, RPE, and TQR values between the groups (p > 0.05). Conclusion: The findings of this study indicate that recovery following HIIT does not differ between the two age groups. Furthermore, older and younger participants displayed similar lactate kinetics after the intermittent exercise protocols.

The Effect of Self-Paced and Prescribed Interset Rest Strategies on Performance in Strength Training

2019 ◽  
Vol 14 (7) ◽  
pp. 980-986
Author(s):  
Peter Ibbott ◽  
Nick Ball ◽  
Marijke Welvaert ◽  
Kevin G. Thompson
Keyword(s):  
Strength Training ◽  
Perceived Exertion ◽  
Mechanical Performance ◽  
Rest Period ◽  
Rating Of Perceived Exertion ◽  
Subjective Rating ◽  
Male Athletes ◽  
Rest Periods ◽  
Pacing Strategies ◽  
Feasible Alternative

Purpose: To assess pacing strategies using prescribed and self-selected interset rest periods and their influence on performance in strength-trained athletes. Methods: A total of 16 strength-trained male athletes completed 3 randomized heavy strength-training sessions (5 sets and 5 repetitions) with different interset rest periods. The interset rest periods were 3 min (3MIN), 5 min (5MIN), and self-selected (SS). Mechanical (power, velocity, work, and displacement), surface electromyography (sEMG), and subjective (rating of perceived exertion) and readiness-to-lift data were recorded for each set. Results: SS-condition interset rest periods increased from sets 1 to 4 (from 207.52 to 277.71 s; P = .01). No differences in mechanical performance were shown between the different interset rest-period conditions. Power output (210 W; 8.03%) and velocity (0.03 m·s−1; 6.73%) decreased as sets progressed for all conditions (P < .001) from set 1 to set 5. No differences in sEMG activity between conditions were shown; however, vastus medialis sEMG decreased as the sets progressed for each condition (1.75%; P = .005). All conditions showed increases in rating of perceived exertion as sets progressed (set 1 = 6.1, set 5 = 7.9; P < .001). Participants reported greater readiness to lift in the 5MIN condition (7.81) than in the 3MIN (7.09) and SS (7.20) conditions (P < .001). Conclusions: Self-selecting interset rest periods does not significantly change performance compared with 3MIN and 5MIN conditions. Given the opportunity, athletes will vary their interset rest periods to complete multiple sets of heavy strength training. Self-selection of interset rest periods may be a feasible alternative to prescribed interset rest periods.

scholarly journals Effects of Half-Time Cooling Using a Fan with Skin Wetting on Thermal Response During Intermittent Cycling Exercise in the Heat

2021 ◽  
Vol 05 (03) ◽  
pp. E91-E98
Author(s):  
Jumpei Osakabe ◽  
Masanobu Kajiki ◽  
Kiho Kondo ◽  
Takaaki Matsumoto ◽  
Yoshihisa Umemura
Keyword(s):  
Perceived Exertion ◽  
Thermal Sensation ◽  
Rating Of Perceived Exertion ◽  
Half Time ◽  
Physiological Strain ◽  
Cycling Exercise ◽  
Repeated Sprint ◽  
Significant Difference ◽  
Sprint Cycling ◽  
Experimental Trials

AbstractThe present study investigated the effects of half-time (HT) break cooling using a fan and damp sponge on physiological and perceptual responses during the 2nd half of a repeated-sprint exercise in a hot environment. Eight physically active men performed a familiarization trial and two experimental trials of a 2×30-min intermittent cycling exercise protocol with a 15-min HT break in hot conditions (35°C, 50% relative humidity). Two experimental trials were conducted in random order: skin wetting with a fan (FANwet) and no cooling (CON). During the 2nd half, a repeated-sprint cycling exercise was performed: i. e., 5 s of maximal pedaling (body weight×0.075 kp) every minute, separated by 25 s of unloaded pedaling (80 rpm) and 30 s of rest. Rectal temperature, skin temperature (chest, forearm, thigh, and calf), heart rate, physiological strain index, rating of perceived exertion, thermal sensation, and comfort were significantly improved in the FANwet condition (P<0.05). There was no significant difference in the repeated-sprint cycling exercise performance between conditions. The results suggest that skin wetting with a fan during the HT break is a practical and effective cooling strategy for mitigating physiological and perceptual strain during the 2nd half in hot conditions.

Effect of ENDUROX™ on Metabolic Responses to Submaximal Exercise

1999 ◽  
Vol 9 (4) ◽  
pp. 434-442 ◽  
Author(s):  
Samuel N. Cheuvront ◽  
Robert J. Moffatt ◽  
Kyle D. Biggerstaff ◽  
Shawn Bearden ◽  
Paul McDonough
Keyword(s):  
Oxygen Consumption ◽  
Repeated Measures ◽  
Perceived Exertion ◽  
Minute Ventilation ◽  
Rating Of Perceived Exertion ◽  
Peak Oxygen Consumption ◽  
Metabolic Responses ◽  
Double Blind ◽  
Serum Glycerol ◽  
Male Subjects

Claims that ENDUROX™ enhances performance by altering metabolic responses to exercise were tested. In a double-blind crossover design, 10 male subjects were randomly assigned to consume 400 mg of placebo or 800 mg ENDUROX™ for 7 days. Cycle ergometry was performed for 30 minutes at 25%, followed by 10 min at 65% of peak oxygen consumption. After a 1-week washout period, subjects performed the identical exercise protocol following 7 days of reciprocal supplemental conditions. Expired gases were collected and analyzed continuously for oxygen consumption, minute ventilation, and respiratory exchange ratio. Heart rate, blood pressure, rating of perceived exertion, blood lactate, and serum glycerol data were also collected at regular intervals. A two-way ANOVA with repeated measures revealed no significant main or interaction effects involving group differences (p > 0.05) between trials for any variable during rest, 25% or 65% (VO2 peak), or recovery. Our findings do not support the ergogenic claims for ENDUROX™.

The Effects of Caffeine in Women during Aerobic-Dance Bench Stepping

2007 ◽  
Vol 17 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Jennifer N. Ahrens ◽  
Lisa K. Lloyd ◽  
Sylvia H. Crixell ◽  
John L. Walker
Keyword(s):  
Heart Rate ◽  
Perceived Exertion ◽  
Minute Ventilation ◽  
Physiological Responses ◽  
Rating Of Perceived Exertion ◽  
Caffeine Ingestion ◽  
Fitness Level ◽  
Aerobic Dance ◽  
Control Body ◽  
And Control

People of all ages and fitness levels participate regularly in aerobic-dance bench stepping (ADBS) to increase fitness and control body weight. Any reasonable method for enhancing the experience or effectiveness of ADBS would be beneficial. This study examined the acute effects of a single dose of caffeine on physiological responses during ADBS in women. When compared with a placebo, neither a 3- nor a 6-mg/kg dose of caffeine altered physiological responses or rating of perceived exertion (RPE) in 20 women (age 19–28 y) of average fitness level, not habituated to caffeine, while they performed an ADBS routine. Since neither dose of caffeine had any effect on VO2, Vco2, minute ventilation, respiratory-exchange ratio, rate of energy expenditure, heart rate, or RPE during ADBS exercise, it would not be prudent for a group exercise leader to recommend caffeine to increase energy cost or decrease perception of effort in an ADBS session. Furthermore, caffeine ingestion should not interfere with monitoring intensity using heart rate or RPE during ADBS.

Control of breathing in Sherpas at low and high altitude

1980 ◽  
Vol 49 (3) ◽  
pp. 374-379 ◽  
Author(s):  
P. H. Hackett ◽  
J. T. Reeves ◽  
C. D. Reeves ◽  
R. F. Grover ◽  
D. Rennie
Keyword(s):  
High Altitude ◽  
Ventilatory Response ◽  
Minute Ventilation ◽  
Acute Hypoxia ◽  
Arterial Oxygen Saturation ◽  
Carbon Dioxide Tension ◽  
Arterial Oxygen ◽  
Hypoxic Ventilatory Response ◽  
Oxygen Administration ◽  
End Tidal

Sherpas are well known for their physical performance at extreme altitudes, yet they are reported to have blunted ventilatory responses to acute hypoxia and relative hypoventilation in chronic hypoxia. To examine this paradox, we studied ventilatory control in Sherpas in comparison to that in Westerners at both low and high altitude. At low altitude, 25 Sherpas had higher minute ventilation, higher respiratory frequency, and lower end-tidal carbon dioxide tension than 25 Westerners. The hypoxic ventilatory response of Sherpas was found to be similar to that in Westerners, even though long altitude exposure had blunted the responses of some Sherpas. At high altitude, Sherpas again had higher minute ventilation and a tendency toward higher arterial oxygen saturation than Westerners. Oxygen administration increased ventilation further in Sherpas but decreased ventilation in Westerners. We conclude that Sherpas differ from other high-altitude natives; their hypoxic ventilatory response is not blunted, and they exhibit relative hyperventilation.

Influence of Local and Central Factors in Dominating Rated Perceived Exertion during Physical Work

1978 ◽  
Vol 46 (3) ◽  
pp. 683-698 ◽  
Author(s):  
Kent B. Pandolf
Keyword(s):  
Perceived Exertion ◽  
Minute Ventilation ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Rating Of Perceived Exertion ◽  
Physical Work ◽  
Subjective Perception ◽  
Local Factor ◽  
Major Factors ◽  
Central Factors

The literature suggests two major factors determine rated perceived exertion during physical work. These two factors are a local factor, i.e., sensations or feelings of strain in the working muscles and/or joints; and a central factor, i.e., sensations or feelings primarily associated with the cardio-respiratory systems. In some experiments heart rate and minute ventilation (central factors) appear to be the dominant cues for rated perceived exertion, while in others, local factors such as blood lactate concentration and muscular discomfort seem to be the prominent cues. However, it appears that when a particular cue is accentuated by either elevated rate, concentration or value over others it can dominate the over-all rating of perceived exertion. After evaluating the existing literature, a model has been introduced to evaluate differentiated ratings of perceived exertion (local and central) in comparison to the over-all measure. This model may help aid in a better understanding of the mechanisms by which the subjective perception of exertion is determined during different types of physical work.

Physiological responses on the Concept II BikeErg and Concept II RowErg in well-trained male rowers

2020 ◽  
pp. 174795412096818
Author(s):  
Kirstie J Turner ◽  
Anthony J Rice
Keyword(s):  
Power Output ◽  
Perceived Exertion ◽  
Minute Ventilation ◽  
Physiological Responses ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Carbon Dioxide Production ◽  
Recovery Phase ◽  
Rating Of Perceived Exertion ◽  
Rate Of Oxygen Consumption

Stationary cycling is a common training mode of rowers, used to provide variety in training programs and prevent overuse injuries commonly associated with the repetitive nature of the rowing stroke. The purpose of this study was to investigate the differences in physiological responses on a Concept II BikeErg (Concept II BikeErg; Concept2 Inc., US) and Concept II RowErg (Concept II Model D; Concept2 Inc., US) at matched submaximal workloads so training load can be appropriately prescribed for stationary cycling. Ten well-trained, male rowers completed 6 min of exercise at four submaximal workloads (50%, 62.5%, 75% and 87.5% of their most recent 2000 m RowErg score) interspersed with 2-minute recovery periods on both ergometers in a single day. Ergometer order was randomised and balanced between groups. At matched power output (PO) results while on the RowErg were significantly higher across all workloads for rate of oxygen consumption ([Formula: see text]), rate of carbon dioxide production ([Formula: see text]), minute ventilation ([Formula: see text]) and heart rate (HR) (p < 0.05) and across the final two workloads for Rating of Perceived Exertion (RPE) and blood lactate concentration (BLa) (p < 0.05). When oxygen uptake at a fixed value ([Formula: see text] = 3.5 L.min−1) was matched between groups results while on the RowErg were significantly lower for PO, BLa, [Formula: see text], RER and RPE whereas [Formula: see text] and HR were similar to the BikeErg. These results support the understanding that displayed power output on the RowErg does not account for all work done during the rowing stroke cycle, specifically during the recovery phase. In conclusion, the physiological responses on the Concept II BikeErg are no more closely aligned to the Concept II RowErg than previously shown for similar cycle ergometers from different manufacturers. Due to the lack of consistency between Concept II BikeErg and Concept II RowErg PO, HR is better suited for the prescription of training loads on the BikeErg.

The Pharmacodynamic Effect of a Remifentanil Bolus on Ventilatory Control

2000 ◽  
Vol 92 (2) ◽  
pp. 393-393 ◽  
Author(s):  
H. Daniel Babenco ◽  
Pattilyn F. Conard ◽  
Jeffrey B. Gross
Keyword(s):  
Carbon Dioxide ◽  
Respiratory Depression ◽  
Response Curve ◽  
Time Course ◽  
Ventilatory Response ◽  
Minute Ventilation ◽  
Effect Site ◽  
Ventilatory Drive ◽  
Ventilatory Depression ◽  
Carbon Dioxide Response

Background In doses typically administered during conscious sedation, remifentanil may be associated with ventilatory depression. However, the time course of ventilatory depression after an initial dose of remifentanil has not been determined previously. Methods In eight healthy volunteers, the authors determined the time course of the ventilatory response to carbon dioxide using the dual isohypercapnic technique. Subjects breathed via mask from a to-and-fro circuit with variable carbon dioxide absorption, allowing the authors to maintain end-tidal pressure of carbon dioxide (PET(CO2)) at approximately 46 or 56 mm Hg (alternate subjects). After 6 min of equilibration, subjects received 0.5 microg/kg remifentanil over 5 s, and minute ventilation (V(E)) was recorded during the next 20 min. Two hours later, the study was repeated using the other carbon dioxide tension (56 or 46 mm Hg). The V(E) data were used to construct two-point carbon dioxide response curves at 30-s intervals after remifentanil administration. Using published pharmacokinetic values for remifentanil and the method of collapsing hysteresis loops, the authors estimated the effect-site equilibration rate constant (k(eo)), the effect-site concentration producing 50% respiratory depression (EC50), and the shape parameter of the concentration-response curve (gamma). Results The slope of the carbon dioxide response decreased from 0.99 [95% confidence limits 0.72 to 1.26] to a nadir of 0.27 l x min(-1) x mm Hg(-1) [-0.12 to 0.66] 2 min after remifentanil (P&lt;0.001); within 5 min, it recovered to approximately 0.6 l x min(-1) x mm Hg(-1), and within 15 min of injection, slope returned to baseline. The computed ventilation at PET = 50 mm Hg (VE50) decreased from 12.9 [9.8 to 15.9] to 6.1 l/min [4.8 to 7.4] 2.5 min after remifentanil injection (P&lt;0.001). This was caused primarily by a decrease in tidal volume rather than in respiratory rate. Estimated pharmacodynamic parameters based on computed mean values of VE50 included k(eo) = 0.24 min(-1) (T1/2 = 2.9 min), EC50 = 1.12 ng/ml, and gamma = 1.74. Conclusions After administration of 0.5 microg/kg remifentanil, there was a decrease in slope and downward shift of the carbon dioxide ventilatory response curve. This reached its nadir approximately 2.5 min after injection, consistent with the computed onset half-time of 2.9 min. The onset of respiratory depression appears to be somewhat slower than previously reported for the onset of remifentanil-induced electroencephalographic slowing. Recovery of ventilatory drive after a small dose essentially was complete within 15 min.

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