Influence of crank rate on the slow component of pulmonary O2 uptake during heavy arm-crank exercise

2006 ◽  
Vol 31 (3) ◽  
pp. 292-301 ◽  
Author(s):  
Paul M Smith ◽  
Eilidh McCrindle ◽  
Mike Doherty ◽  
Michael J Price ◽  
Andrew M Jones
Keyword(s):  
Oxygen Uptake ◽  
Peak Power ◽  
Slow Component ◽  
Work Rate ◽  
Rating Of Perceived Exertion ◽  
Muscle Fibres ◽  
External Work ◽  
Tension Development ◽  
Significant Difference ◽  
The Mean

The principal aim of this study was to examine the influence of variations in crank rate on the slow component of the pulmonary oxygen uptake ([Formula: see text]O2) response to heavy-intensity arm-crank ergometry (ACE). We hypothesized that, for the same external work rate, a higher crank rate would elicit a greater amplitude of the [Formula: see text]O2 "slow component". Eleven healthy males (mean (± SD) age, 25 (±6) y; body mass, 89.1 (±10.7) kg; ACE [Formula: see text]O2 peak, 3.36 (±0.47) L·min-1) volunteered to participate. The subjects initially completed an incremental exercise test for the determination of [Formula: see text]O2 peak and peak power on an electrically braked arm ergometer. Subsequently, they completed "step" transitions from an unloaded baseline to a work rate requiring 70% of peak power: 2 at a crank rate of 50 r·min-1 (LO) and 2 at a crank rate of 90 r·min-1 (HI). Pulmonary gas exchange was measured on a breath-by-breath basis and [Formula: see text]O2 kinetics were evaluated from the mean response to each condition using non-linear regression techniques. In contradiction to our hypothesis, the [Formula: see text]O2 slow component was significantly greater at 50 r·min-1 than at 90 r·min-1 (LO: 0.60 ± 0.30 vs. HI: 0.47 ± 0.21 L·min-1; p < 0.05). The mean value for the localized rating of perceived exertion was also higher at 50 r·min-1 than at 90 r·min-1 (LO: 16.7 ± 1.4 vs. HI: 15.2 ± 1.3; p < 0.05), but there was no significant difference in end-exercise blood lactate concentration. It is possible that differences in muscle tension development and blood flow resulted in a greater contribution of "low-efficiency" type II muscle fibres to force production at the lower crank rate in ACE, and that this was linked to the greater [Formula: see text]O2 slow component. However, other factors such as greater isometric contraction of the muscles of the trunk and legs at the lower crank rate might also be implicated.Key words: O2 kinetics, [Formula: see text]O2 slow component, fibre recruitment, oxygen uptake.

Carbohydrate Drink Use During 30 Minutes of Variable-Intensity Exercise Has No Effect on Exercise Performance in Premenarchal Girls

2021 ◽  
Vol 33 (2) ◽  
pp. 65-69
Author(s):  
C. Eric Heidorn ◽  
Brandon J. Dykstra ◽  
Cori A. Conner ◽  
Anthony D. Mahon
Keyword(s):  
Peak Power ◽  
Perceived Exertion ◽  
Rating Of Perceived Exertion ◽  
Fatigue Index ◽  
Mean Power ◽  
Variable Intensity ◽  
Performance Effects ◽  
Power Peak ◽  
The Mean ◽  
And Performance

Purpose: This study examined the physiological, perceptual, and performance effects of a 6% carbohydrate (CHO) drink during variable-intensity exercise (VIE) and a postexercise test in premenarchal girls. Methods: A total of 10 girls (10.4 [0.7] y) participated in the study. VO2peak was assessed, and the girls were familiarized with VIE and performance during the first visit. The trial order (CHO and placebo) was randomly assigned for subsequent visits. The drinks were given before VIE bouts and 1-minute performance (9 mL/kg total). Two 15-minute bouts of VIE were completed (10 repeated sequences of 20%, 55%, and 95% power at VO2peak and maximal sprints) before a 1-minute performance sprint. Results: The mean power, peak power, heart rate (HR), %HRpeak, and rating of perceived exertion during VIE did not differ between trials. However, the peak power decreased, and the rating of perceived exertion increased from the first to the second bout. During the 1-minute performance, there were no differences between the trial (CHO vs placebo) for HR (190 [9] vs 189 [9] bpm), %HRpeak (97.0% [3.2%] vs 96.6% [3.0%]), rating of perceived exertion (7.8 [2.3] vs 8.1 [1.9]), peak power (238 [70] vs 235 [60] W), fatigue index (54.7% [10.0%] vs 55.9% [12.8%]), or total work (9.4 [2.6] vs 9.4 [2.1] kJ). Conclusion: CHO supplementation did not alter physiological, perceptual, or performance responses during 30 minutes of VIE or postexercise sprint performance in premenarchal girls.

Validity and Reliability of a New Karate-Specific Aerobic Field Test for Karatekas

2014 ◽  
Vol 9 (6) ◽  
pp. 953-958 ◽  
Author(s):  
Montassar Tabben ◽  
Jeremy Coquart ◽  
Helmi Chaabène ◽  
Emerson Franchini ◽  
Karim Chamari ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Laboratory Test ◽  
Body Mass ◽  
Field Test ◽  
Scientific Data ◽  
Rating Of Perceived Exertion ◽  
Time To Exhaustion ◽  
Validity And Reliability ◽  
Specific Field ◽  
Significant Difference

Purpose:This study determined the validity and reliability of a new specific field test that was based on the scientific data from the latest research.Methods:Seventeen international-level karatekas participated in the study: 14 men (age 24.1 ± 4.6 y, body mass 65.7 ± 10.8 kg) and 3 women (age 19 ± 3.6 y, body mass 54.1 ± 0.9 kg). All performed the new karate-specific test (KST) 2 times (test and retest sessions were carried out on separated occasions 1 wk apart). Thirteen men also performed a laboratory test to assess maximal oxygen uptake (VO2max).Results:Test–retest results showed the KST to be reliable. Peak oxygen uptake (VO2peak), peak heart rate (HRpeak), blood lactate concentration, rating of perceived exertion, and time to exhaustion (TE) did not display a difference between the test and the retest. The SEM and ICC for relative and absolute VO2peakand TE were <5% and >.90, respectively. Significant correlations were found between VO2peak(mL · kg−1· min−1) and TE measured from the KST (r= .71, 95%CI 0.35–0.88,P< .0001). There was also no significant difference between VO2peakmeasured from the KST and VO2maxrecorded from the cycle-ergometer laboratory test (55.1 ± 4.8 vs 53.2 ± 6.6 mL · kg−1· min−1, respectively;t= –1.85, df = 12,P= .08,dz= 0.51 [small]). The Bland and Altman analyses reported a mean difference (bias) ± the 95% limits of agreement of 1.9 ± 7.35 mL · kg−1· min−1.Conclusions:This study showed that the new KST test, with effort patterns replicating real karate combat sessions, can be considered a valid and reliable karate-specific field test for assessing karatekas’ endurance fitness.

Influence of exercise intensity on pulmonary oxygen uptake kinetics at the onset of exercise and recovery in male adolescents

2008 ◽  
Vol 33 (1) ◽  
pp. 107-117 ◽  
Author(s):  
Nicola Lai ◽  
Melita M. Nasca ◽  
Marco A. Silva ◽  
Fatima T. Silva ◽  
Brian J. Whipp ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Slow Component ◽  
Work Rate ◽  
Moderate Intensity ◽  
Heavy Exercise ◽  
Pulmonary Oxygen Uptake ◽  
Square Wave ◽  
Male Adolescents ◽  
Double Exponential ◽  
Single Exponential

The dynamics of the pulmonary oxygen uptake (VO2) responses to square-wave changes in work rate can provide insight into bioenergetic processes sustaining and limiting exercise performance. The dynamic responses at the onset of exercise and during recovery have been investigated systematically and are well characterized at all intensities in adults; however, they have not been investigated completely in adolescents. We investigated whether adolescents display a slow component in their VO2 on- and off-kinetic responses to heavy- and very heavy-intensity exercise, as demonstrated in adults. Healthy African American male adolescents (n = 9, 14–17 years old) performed square-wave transitions on a cycle ergometer (from and to a baseline work rate of 20 W) to work rates of moderate (M), heavy (H), and very heavy (VH) intensity. In all subjects, the VO2 on-kinetics were best described with a single exponential at moderate intensity (τ1, on = 36 ± 11 s) and a double exponential at heavy (τ1, on = 29 ± 9 s; τ2, on = 197 ± 92 s) and very heavy (τ1, on = 36 ± 9 s; τ2, on = 302 ± 14 s) intensities. In contrast, the VO2 off-kinetics were best described with a single exponential at moderate (τ1, off = 48 ± 9 s) and heavy (τ1, off = 53 ± 7 s) intensities and a double exponential at very heavy (τ1, off = 51 ± 3 s; τ2, off = 471 ± 54 s) intensity. In summary, adolescents consistently displayed a slow component during heavy exercise (on- but not off- transition) and very heavy exercise (on- and off-transitions). Although the overall response dynamics in adolescents were similar to those previously observed in adults, their specific characterizations were different, particularly the lack of symmetry between the on- and off-responses.

scholarly journals Acute Effects of Using Added Respiratory Dead Space Volume in a Cycling Sprint Interval Exercise Protocol: A Cross-Over Study

2020 ◽  
Vol 17 (24) ◽  
pp. 9485
Author(s):  
Natalia Danek ◽  
Kamil Michalik ◽  
Marcin Smolarek ◽  
Marek Zatoń
Keyword(s):  
Oxygen Uptake ◽  
Dead Space ◽  
Perceived Exertion ◽  
Respiratory Acidosis ◽  
Rating Of Perceived Exertion ◽  
Interval Exercise ◽  
Dead Space Volume ◽  
The Mean ◽  
Respiratory Dead Space ◽  
Space Volume

Background: The aim of the study was to compare acute physiological, biochemical, and perceptual responses during sprint interval exercise (SIE) with breathing through a device increasing added respiratory dead space volume (ARDSV) and without the device. Methods: The study involved 11 healthy, physically active men (mean maximal oxygen uptake: 52.6 ± 8.2 mL∙kg1∙min−1). During four visits to a laboratory with a minimum interval of 72 h, they participated in (1) an incremental test on a cycle ergometer; (2) a familiarization session; (3) and (4) cross-over SIE sessions. SIE consisted of 6 × 10-s all-out bouts with 4-min active recovery. During one of the sessions the participants breathed through a 1200-mL ARDSv (SIEARDS). Results: The work performed was significantly higher by 4.4% during SIEARDS, with no differences in the fatigue index. The mean respiratory ventilation was significantly higher by 13.2%, and the mean oxygen uptake was higher by 31.3% during SIEARDS. Respiratory muscle strength did not change after the two SIE sessions. In SIEARDS, the mean pH turned out significantly lower (7.26 vs. 7.29), and the mean HCO3– concentration was higher by 7.6%. Average La− and rating of perceived exertion (RPE) did not differ between the sessions. Conclusions: Using ARDSV during SIE provokes respiratory acidosis, causes stronger acute physiological responses, and does not increase RPE.

scholarly journals Agreement analysis between critical power and intensity corresponding to 50% in cycling exercise

2016 ◽  
Vol 18 (2) ◽  
pp. 197 ◽  
Author(s):  
Kristopher Mendes de Souza ◽  
Ricardo Dantas de Lucas ◽  
Paulo Cesar do Nascimento Salvador ◽  
Lucas Crescenti Abdalla Saad Helal ◽  
Luiz Guilherme Antonacci Guglielmo ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Lactate Threshold ◽  
Critical Power ◽  
Limits Of Agreement ◽  
Cycling Exercise ◽  
Significant Difference ◽  
The Mean ◽  
The Difference ◽  
Male Subjects ◽  
Level Of Agreement

DOI: http://dx.doi.org/10.5007/1980-0037.2016v18n2p197 The purpose of this study was to determine the level of agreement between critical power (CP) and intensity corresponding to 50% of the difference (50% Δ) between oxygen uptake (VO2) at lactate threshold (LT) and maximal oxygen uptake (VO2max) in untrained subjects during cycling exercise. Fifteen healthy male subjects (age: 26.0 ± 3.5 years; body weight: 76.6 ± 10.4 kg; height: 178.2 ± 7.6 cm) volunteered to participate in the study. Each subject performed a series of tests to determine LT, VO2LT, CP, VO2CP, 50% Δ, VO250% Δ, and VO2max. The values of LT, VO2LT, CP, VO2CP, 50% Δ, VO250% Δ and VO2max were 109 ± 15 W, 1.84 ± 0.23 L.min-1, 207 ± 17 W, 2.78 ± 0.27 L.min-1, 206 ± 19 W, 2.77 ± 0.29 L.min-1, and 3.71 ± 0.49 L.min-1, respectively. No significant difference was found between CP and 50% Δ (t = 0.16; p = 0.87) or between VO2CP and VO250% Δ (t = 0.12; p = 0.90). However, the bias ± 95% limits of agreement for comparison between CP and 50% Δ and between VO2CP and VO250% Δ were 1 ± 27 W (0.3 ± 14.1%) and 0.01 ± 0.24 L.min-1 (0.2 ± 8.9%), respectively. In summary, the mean CP and 50% Δ values were not significantly different. However, considering the limits of agreement between the two intensities, CP estimated based on 50% Δ might result in a remarkable error when the absolute variability of individual differences is taken into account

A Maximal Rowing Ergometer Protocol to Predict Maximal Oxygen Uptake

2020 ◽  
pp. 1-5
Author(s):  
Kurt Jensen ◽  
Morten Frydkjær ◽  
Niels M.B. Jensen ◽  
Lucas M. Bannerholt ◽  
Søren Gam
Keyword(s):  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Average Power ◽  
Maximal Power Output ◽  
Significant Difference ◽  
Rowing Ergometer ◽  
The Mean ◽  
Ergometer Test ◽  
The Relationship ◽  
Very High

Purpose: To examine the relationship between the maximal power output (MPO) in an individualized 7 × 2-minute incremental (INCR) test, average power in a 2k (W2k) rowing ergometer test, and maximal oxygen uptake () and to develop a regression equation to predict . Methods: A total of 34 male club rowers (age 18–30 y) performed a 2k and an INCR test in a Concept2 rowing ergometer to determine and compare MPO, W2k, and . Results: No significant difference was found between measured during INCR or 2k test (P = .73). A very high correlation coefficient (r = .96) was found between MPO and and between W2k and (r = .93). Linear regression analyses were developed for predicting from MPO: (1)  (mL·min−1) = 11.49 × MPO + 810 and from W2k: (2)  = 10.96 × W2k + 1168. Cross-validation analyses were performed using an independent sample of 14 rowers. There was no difference between the mean predicted in the INCR test (4.41 L·min−1) or the 2k test (4.39 L·min−1) and the observed (4.40 L·min−1). Technical error of measurement was 3.1% and 3.6%, standard error of estimate was 0.136 and 0.157 mL·min−1, and validation coefficients (r) were .95 and .94 using Equation (1) and (2), respectively. Conclusion: A prediction model only including MPO or W2k explains 88% to 90% of the variability in and is suggested for practical use in male club rowers.

Electromyographic and Mechanomyographic Responses at Critical Power

2000 ◽  
Vol 25 (4) ◽  
pp. 262-270 ◽  
Author(s):  
Anthony J. Bull ◽  
Terry J. Housh ◽  
Glen O. Johnson ◽  
Sharon R. Perry
Keyword(s):  
Peak Power ◽  
Critical Power ◽  
Slow Component ◽  
Vastus Lateralis ◽  
Muscular Activity ◽  
Cycle Ergometry ◽  
Slope Coefficient ◽  
The Mean ◽  
Power Outputs ◽  
Amplitude Versus

The purpose of the present study was to determine the electromyographic (EMG) and mechanomyographic (MMG) responses to cycle ergometry at critical power (CP). Seven moderately active males (25 ± 3 years) completed a 60-min trial at their CP estimated from a nonlinear, 3 parameter regression model. EMG and MMG amplitudes were recorded from the vastus lateralis during 60-min continuous rides at CP. The mean CP was 175 ± 25 W, which represented 56 ± 5% of the subjects' peak power outputs. The results indicated that the slope coefficient for the EMG amplitude versus time relationship was not significantly different from zero; however, MMG amplitude decreased significantly over the 60 min. This dissociation between the electrical (EMG) and mechanical (MMG) aspects of muscular activity during cycle ergometry may be due to neuromuscular changes associated with "muscle wisdom" or changes in muscular compliance. Key words: cycle ergometry, fatigue, muscle wisdom, [Formula: see text] slow component

scholarly journals Effects of prior heavy exercise on phase II pulmonary oxygen uptake kinetics during heavy exercise

2000 ◽  
Vol 89 (4) ◽  
pp. 1387-1396 ◽  
Author(s):  
Mark Burnley ◽  
Andrew M. Jones ◽  
Helen Carter ◽  
Jonathan H. Doust
Keyword(s):  
Oxygen Uptake ◽  
Phase Ii ◽  
Slow Component ◽  
Exercise Bout ◽  
Oxygen Uptake Kinetics ◽  
Cycle Ergometer ◽  
Moderate Exercise ◽  
Heavy Exercise ◽  
Mean Response Time ◽  
The Mean

We tested the hypothesis that heavy-exercise phase II oxygen uptake (V˙o 2) kinetics could be speeded by prior heavy exercise. Ten subjects performed four protocols involving 6-min exercise bouts on a cycle ergometer separated by 6 min of recovery: 1) moderate followed by moderate exercise; 2) moderate followed by heavy exercise; 3) heavy followed by moderate exercise; and 4) heavy followed by heavy exercise. The V˙o 2 responses were modeled using two (moderate exercise) or three (heavy exercise) independent exponential terms. Neither moderate- nor heavy-intensity exercise had an effect on the V˙o 2 kinetic response to subsequent moderate exercise. Although heavy-intensity exercise significantly reduced the mean response time in the second heavy exercise bout (from 65.2 ± 4.1 to 47.0 ± 3.1 s; P < 0.05), it had no significant effect on either the amplitude or the time constant (from 23.9 ± 1.9 to 25.3 ± 2.9 s) of theV˙o 2 response in phase II. Instead, this “speeding” was due to a significant reduction in the amplitude of the V˙o 2 slow component. These results suggest phase II V˙o 2 kinetics are not speeded by prior heavy exercise.

The Self-Paced VO2max Test to Assess Maximal Oxygen Uptake in Highly Trained Runners

2015 ◽  
Vol 10 (2) ◽  
pp. 172-177 ◽  
Author(s):  
James S. Hogg ◽  
James G. Hopker ◽  
Alexis R. Mauger
Keyword(s):  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Perceived Exertion ◽  
Rating Of Perceived Exertion ◽  
The Novel ◽  
Distance Runners ◽  
Suitable Alternative ◽  
Significant Difference ◽  
Graded Exercise ◽  
Trained Runners

Purpose:The novel self-paced maximal-oxygen-uptake (VO2max) test (SPV) may be a more suitable alternative to traditional maximal tests for elite athletes due to the ability to self-regulate pace. This study aimed to examine whether the SPV can be administered on a motorized treadmill.Methods:Fourteen highly trained male distance runners performed a standard graded exercise test (GXT), an incline-based SPV (SPVincline), and a speed-based SPV (SPVspeed). The GXT included a plateau-verification stage. Both SPV protocols included 5 × 2-min stages (and a plateau-verification stage) and allowed for self-pacing based on fixed increments of rating of perceived exertion: 11, 13, 15, 17, and 20. The participants varied their speed and incline on the treadmill by moving between different marked zones in which the tester would then adjust the intensity.Results:There was no significant difference (P = .319, ES = 0.21) in the VO2max achieved in the SPVspeed (67.6 ± 3.6 mL · kg−1 · min−1, 95%CI = 65.6–69.7 mL · kg−1 · min−1) compared with that achieved in the GXT (68.6 ± 6.0 mL · kg−1 · min−1, 95%CI = 65.1–72.1 mL · kg−1 · min−1). Participants achieved a significantly higher VO2max in the SPVincline (70.6 ± 4.3 mL · kg−1 · min−1, 95%CI = 68.1–73.0 mL · kg−1 · min−1) than in either the GXT (P = .027, ES = 0.39) or SPVspeed (P = .001, ES = 0.76).Conclusions:The SPVspeed protocol produces VO2max values similar to those obtained in the GXT and may represent a more appropriate and athlete-friendly test that is more oriented toward the variable speed found in competitive sport.

scholarly journals Monitoring Different Types of Resistance Training Using Session Rating of Perceived Exertion

2007 ◽  
Vol 2 (1) ◽  
pp. 34-45 ◽  
Author(s):  
Favil Singh ◽  
Carl Foster ◽  
David Tod ◽  
Michael R. McGuigan
Keyword(s):  
Resistance Training ◽  
Perceived Exertion ◽  
Rating Of Perceived Exertion ◽  
Type Method ◽  
Significant Difference ◽  
Different Types ◽  
The Mean ◽  
Overall Resistance ◽  
Male Subjects ◽  
Familiarization Session

Purpose:To evaluate the effectiveness of session rating of perceived exertion (RPE) to measure effort during different types of resistance training.Method:Fifteen male subjects (age 26.7 ± 4.3 years) performed 3 protocols. All protocols consisted of same 5 exercises but with different intensities, rest periods, and numbers of repetitions. One-repetition maximum (1-RM) was defined as the maximal amount of weight that an individual could lift 1 time without support. The strength protocol included 3 sets of 5 repetitions at 90% of 1-RM with 3 minutes rest between. The hypertrophy session included 3 sets of 10 repetitions at 70% with 1 minute of rest, and the power session included 3 sets of 5 repetitions at 50% with 3 minutes of rest. Session RPE is a modification of the standard RPE scale. Session and standard RPE were measured after the completion of each set and 30 minutes postexercise, respectively.Results:Results showed a difference between both the 2 RPE values of the strength and hypertrophy protocols (P ≤ .05) but no difference between mean and session RPE values for the power protocol. During the familiarization session, session RPE was measured at 5-minute intervals for 30 minutes postexercise. There was a significant difference (P ≤ .05) between the mean RPE values at the fifth and tenth minutes postexercise when compared with 30 minutes postexercise. All other session RPE values showed no significant difference.Conclusion:The session RPE method appears to be effective in monitoring different types of resistance training, and session RPE after 30 minutes was a better indicator of the overall resistance sessions than average RPE.

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