scholarly journals The Reliability of Measuring Gross Efficiency During High-Intensity Cycling Exercise

2020 ◽  
Vol 15 (1) ◽  
pp. 126-132
Author(s):  
Richard Ebreo ◽  
Louis Passfield ◽  
James Hopker
Keyword(s):  
Oxygen Consumption ◽  
High Intensity ◽  
Aerobic Power ◽  
Maximal Aerobic Power ◽  
Limits Of Agreement ◽  
Cycling Exercise ◽  
Gross Efficiency ◽  
Before And After ◽  
Excess Postexercise Oxygen Consumption ◽  
Aerobic And Anaerobic

Purpose: To evaluate the reliability of calculating gross efficiency (GE) conventionally and using a back extrapolation (BE) method during high-intensity exercise (HIE). Methods: A total of 12 trained participants completed 2 HIE bouts (P1 = 4 min at 80% maximal aerobic power [MAP]; P2 = 4 min at 100%MAP). GE was calculated conventionally in the last 3 minutes of submaximal (50%MAP) cycling bouts performed before and after HIE (Pre50%MAP and Post50%MAP). To calculate GE using BE (BGE), a linear regression of GE submaximal values post-HIE were back extrapolated to the end of the HIE bout. Results: BGE was significantly correlated with Post50%MAP GE in P1 (r = .63; P = .01) and in P2 (r = .85; P = .002). Reliability data for P1 and P2 BGE demonstrate a mean coefficient of variation of 7.8% and 9.8% with limits of agreement of 4.3% and 4.5% in relative GE units, respectively. P2 BGE was significantly lower than P2 Post50%MAP GE (18.1% [1.6%] vs 20.3% [1.7%]; P = .01). Using a declining GE from the BE method, there was a 44% greater anaerobic contribution compared with assuming a constant GE during 4-minute HIE at 100%MAP. Conclusion: HIE acutely reduced BGE at 100%MAP. A greater anaerobic contribution to exercise as well as excess postexercise oxygen consumption at 100%MAP may contribute to this decline in efficiency. The BE method may be a reliable and valid tool in both estimating GE during HIE and calculating aerobic and anaerobic contributions.

Recovery of Cycling Gross Efficiency After Time-Trial Exercise

2018 ◽  
Vol 13 (8) ◽  
pp. 1028-1033 ◽  
Author(s):  
Sjors Groot ◽  
Lars H.J. van de Westelaken ◽  
Dionne A. Noordhof ◽  
Koen Levels ◽  
Jos J. de Koning
Keyword(s):  
High Intensity ◽  
Time Course ◽  
Time Trial ◽  
Exercise Bout ◽  
Submaximal Exercise ◽  
High Intensity Exercise ◽  
Cycling Exercise ◽  
Gross Efficiency ◽  
Before And After ◽  
The Difference

Background: Research has shown that gross efficiency (GE) declines during high-intensity exercise, but the time course of recovery of GE after high-intensity exercise has not yet been investigated. Purpose: To determine the time course of the recovery of GE after time trials (TTs) of different lengths. Methods: Nineteen trained male cyclists participated in this study. Before and after TTs of 2000 and 20,000 m, subjects performed submaximal exercise at 55% of the power output attained at maximal oxygen uptake (PVO2max). The postmeasurement continued until 30 min after the end of the TT, during which GE was determined over 3-min intervals. The magnitude-based-inferences approach was used for statistical analysis. Results: GE decreased substantially during the 2000-m and 20,000-m TTs (−11.8% [3.6%] and −6.2% [4.0%], respectively). A most likely and very likely recovery of GE was found during the first half of the submaximal exercise bout performed after the 2000-m, with only a possible increase in GE during the first part of the submaximal exercise bout performed after the 20,000-m. After both distances, GE did not fully recover to the initial pre-TT values, as the difference between the pre-TT value and average GE value of minutes 26–29 was still most likely negative for both the 2000- and 20,000-m (−6.1% [2.8%] and −7.0% [4.5%], respectively). Conclusions: It is impossible to fully recover GE after TTs of 2000- or 20,000-m during 30 min of submaximal cycling exercise performed at an intensity of 55% PVO2max.

scholarly journals Modulation of Endothelial Glycocalyx and Microcirculation in Healthy Young Men during High-Intensity Sprint Interval Cycling-Exercise by Supplementation with Pomegranate Extract. A Randomized Controlled Trial

2020 ◽  
Vol 17 (12) ◽  
pp. 4405
Author(s):  
Zivile Pranskuniene ◽  
Egle Belousoviene ◽  
Neringa Baranauskiene ◽  
Nerijus Eimantas ◽  
Egle Vaitkaitiene ◽  
...  
Keyword(s):  
High Intensity ◽  
Controlled Trial ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Endothelial Glycocalyx ◽  
Control Group ◽  
Cycling Exercise ◽  
Before And After ◽  
Interval Cycling ◽  
Experimental Group

The natural components of the pomegranate fruit may provide additional benefits for endothelial function and microcirculation. It was hypothesized that supplementation with pomegranate extract might improve glycocalyx properties and microcirculation during acute high-intensity sprint interval cycling exercise. Eighteen healthy and recreationally active male volunteers 22–28 years of age were recruited randomly to the experimental and control groups. The experimental group was supplemented with pomegranate extract 20 mL (720 mg phenolic compounds) for two weeks. At the beginning and end of the study, the participants completed a high-intensity sprint interval cycling-exercise protocol. The microcirculation flow and density parameters, glycocalyx markers, systemic hemodynamics, lactate, and glucose concentration were evaluated before and after the initial and repeated (after 2 weeks supplementation) exercise bouts. There were no significant differences in the microcirculation or glycocalyx over the course of the study (p < 0.05). The lactate concentration was significantly higher in both groups after the initial and repeated exercise bouts, and were significantly higher in the experimental group compared to the control group after the repeated bout: 13.2 (11.9–14.8) vs. 10.3 (9.3–12.7) mmol/L, p = 0.017. Two weeks of supplementation with pomegranate extract does not influence changes in the microcirculation and glycocalyx during acute high-intensity sprint interval cycling-exercise. Although an unexplained rise in blood lactate concentration was observed.

Preseason Training Improves Perception of Fatigue and Recovery From a Futsal Training Session

2020 ◽  
pp. 1-8
Author(s):  
Carolina Franco Wilke ◽  
Samuel P. Wanner ◽  
Eduardo M. Penna ◽  
André Maia-Lima ◽  
Weslley H.M. Santos ◽  
...  
Keyword(s):  
Creatine Kinase ◽  
High Intensity ◽  
Aerobic Power ◽  
Training Session ◽  
Maximal Aerobic Power ◽  
Total Quality ◽  
Perception Of Effort ◽  
Recovery Profile ◽  
Tactical Training ◽  
Mood Scale

Purpose: To compare the posttraining recovery timeline of elite Brazilian futsal athletes before (Pre-PS) and after 10 weeks of the preseason (Post-PS) period of high-intensity technical–tactical training. Methods: At the start (n = 13) and at the end of the preseason (n = 7), under-20 male futsal players undertook fitness testing for maximal aerobic power, the countermovement jump (CMJ), and the 10-m sprint with change of direction. Furthermore, at both Pre-PS and Post-PS, the players participated in a training session where performance and psychophysiological measures were recorded before, immediately, 3, 24, and 48 hours postsession. The measures included CMJ, 10-m sprint, creatine kinase, Total Quality Recovery Scale, and Brunel Mood Scale. Effect size (ES) analyses compared fitness and posttraining recovery values for each parameter at Pre-PS versus Post-PS. Results: Only trivial ES (−0.02 to 0.11) was evident in maximal aerobic power, CMJ, and 10-m sprint at Post-PS compared with Pre-PS. For the timeline of recovery, only trivial and small ESs were evident for the 10-m sprint (−0.12 to 0.49), though CMJ recovery was improved at 3 hours (0.87) and 48 hours (1.27) at Post-PS and creatine kinase was lower at 48 hours (−1.33) at Post-PS. Perception of recovery was improved in Post-PS at 3 hours (1.50) and 24 hours postsession (0.92). Furthermore, perception of effort was lower immediately after the session (−0.29), fatigue was lower at 3 hours (−0.63), and vigor responses were improved in all postseason assessments (0.59 to 1.13). Conclusion: Despite minimal changes in fitness, preseason training attenuated players’ perception of effort and fatigue and improved their recovery profile following a high-intensity technical–tactical training session.

scholarly journals The effect of exercise intensity and excess postexercise oxygen consumption on postprandial blood lipids in physically inactive men

2017 ◽  
Vol 42 (9) ◽  
pp. 986-993 ◽  
Author(s):  
Laurel A. Littlefield ◽  
Zacharias Papadakis ◽  
Katie M. Rogers ◽  
José Moncada-Jiménez ◽  
J. Kyle Taylor ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Energy Expenditure ◽  
Oxygen Uptake ◽  
Test Meal ◽  
High Intensity ◽  
Postprandial Lipemia ◽  
High Intensity Exercise ◽  
Low Intensity ◽  
Low Intensity Exercise ◽  
Excess Postexercise Oxygen Consumption

Reductions in postprandial lipemia have been observed following aerobic exercise of sufficient energy expenditure. Increased excess postexercise oxygen consumption (EPOC) has been documented when comparing high- versus low-intensity exercise. The contribution of EPOC energy expenditure to alterations in postprandial lipemia has not been determined. The purpose of this study was to evaluate the effects of low- and high-intensity exercise on postprandial lipemia in healthy, sedentary, overweight and obese men (age, 43 ± 10 years; peak oxygen consumption, 31.1 ± 7.5 mL·kg−1·min−1; body mass index, 31.8 ± 4.5 kg/m2) and to determine the contribution of EPOC to reductions in postprandial lipemia. Participants completed 4 conditions: nonexercise control, low-intensity exercise at 40%–50% oxygen uptake reserve (LI), high-intensity exercise at 70%–80% oxygen uptake reserve (HI), and HI plus EPOC re-feeding (HI+EERM), where the difference in EPOC energy expenditure between LI and HI was re-fed in the form of a sports nutrition bar (Premier Nutrition Corp., Emeryville, Calif., USA). Two hours following exercise participants ingested a high-fat (1010 kcals, 99 g sat fat) test meal. Blood samples were obtained before exercise, before the test meal, and at 2, 4, and 6 h postprandially. Triglyceride incremental area under the curve was significantly reduced following LI, HI, and HI+EERM when compared with nonexercise control (p < 0.05) with no differences between the exercise conditions (p > 0.05). In conclusions, prior LI and HI exercise equally attenuated postprandial triglyceride responses to the test meal. The extra energy expended during EPOC does not contribute significantly to exercise energy expenditure or to reductions in postprandial lipemia in overweight men.

Influence of Diet and/or Exercise on Body Composition and Cardiorespiratory Fitness in Obese Women

1998 ◽  
Vol 8 (3) ◽  
pp. 213-222 ◽  
Author(s):  
Alan C. Utter ◽  
David C. Nieman ◽  
Elizabeth M. Shannonhouse ◽  
Diane E. Butterworth ◽  
Cathy N. Nieman
Keyword(s):  
Body Composition ◽  
Cardiorespiratory Fitness ◽  
Aerobic Power ◽  
Maximal Aerobic Power ◽  
Aerobic Exercise Training ◽  
Obese Women ◽  
Intervention Period ◽  
Maximum Heart Rate ◽  
Before And After ◽  
Obese Subjects

The purpose of this study was to measure the influence of diet, exercise, or both on body composition and cardiorespiratory fitness in obese women. Ninety-one obese subjects were randomized into one of four groups: diet (D) (4.19–5.44 MJ or 1,200–1,300 kcal/day), exercise (E) (five 45-min sessions at 78.5 ± 0.5% maximum heart rate), exercise and diet (ED), and controls (C). Maximal aerobic power and body composition were measured in all subjects before and after a 12-week diet intervention period. Subjects in D and ED lost 7.8 ± 0.7 and 8.1 ± 0.6 kg body mass, with no significant change for E relative to C. Losses of percent body fat and fat mass were significantly greater in D and ED but not in E relative to C. The change in VO2max was greater in ED and E but not D when compared to C. Results indicate that moderate aerobic exercise training during a 12-week period has no discernible effects on body composition but does improve cardiorespiratory fitness in dieting obese women.

Dependence of the Nature of the Pedaling Activity on Maximal Aerobic Power in Cycling

2017 ◽  
Vol 12 (1) ◽  
pp. 44-49 ◽  
Author(s):  
Anthony Bouillod ◽  
Julien Pinot ◽  
Flavien Soenen ◽  
Theo Ouvrard ◽  
Frederic Grappe
Keyword(s):  
Exercise Test ◽  
Environmental Conditions ◽  
Power Output ◽  
Aerobic Power ◽  
Cycle Ergometer ◽  
Maximal Aerobic Power ◽  
Limits Of Agreement ◽  
Incremental Test ◽  
Incremental Exercise Test ◽  
Adaptation To Training

Purpose:To analyze the effect of the pedaling activity in different 4-min time trials (TT4s) (laboratory and field conditions) and compare TT4 and maximal aerobic power (MAP) determined from the classical incremental exercise test in laboratory. It was hypothesized that the exercises performed on the field would determine higher physical (power output [PO]) and mental involvements due to different environmental conditions.Methods:Sixteen male cyclists underwent an incremental test to exhaustion and 3 TT4s under different conditions: cycle ergometer (CE), level ground (LG), and uphill (UP).Results:Correlation was observed for PO with a trivial effect size and narrow limits of agreement between MAP and CE TT4 (r = .96, P < .001). The comparison between the CE, LG, and UP tests indicates that PO was significantly higher in UP than in CE (+8.0%, P < .001) and LG (+11.0%, P < .001).Conclusions:The results suggest that PO depends on the nature of the pedaling activity. Moreover, PO under CE TT4 is a relevant predictor of MAP. It seems important to measure MAP by taking into account the cycling conditions, considering that coaches and scientists use this parameter to assess the aerobic potential of athletes and determine the exercise intensities useful for monitoring adaptation to training.

scholarly journals Cardiac remodeling after six weeks of high-intensity interval training to exhaustion in endurance-trained males

2019 ◽  
Author(s):  
Haïfa Mahjoub ◽  
Olivier Le Blanc ◽  
Myriam Paquette ◽  
Sarah Imhoff ◽  
Lawrence Labrecque ◽  
...  
Keyword(s):  
Blood Pressure ◽  
High Intensity ◽  
Aerobic Power ◽  
Interval Training ◽  
Maximal Aerobic Power ◽  
Training Intensity ◽  
High Intensity Interval Training ◽  
High Intensity Interval ◽  
And Function ◽  
The Impact

ABSTRACTHigh-intensity interval training (HIIT) improves physical performance of endurance athletes, although studies examining its cardiovascular effects are sparse. We evaluated the impact of HIIT on blood pressure, heart rate and cardiac cavities size and function in endurance-trained adults. Seventeen endurance-trained males underwent 24-hour ambulatory blood pressure monitoring (ABPM) and Doppler echocardiography at baseline and after 6 weeks of HIIT. Participants were divided in 2 groups (85% maximal aerobic power (MP); HIIT85, n=8 and 115% MP; HIIT115, n = 9) in order to compare the impact of different HIIT intensities. ABPM and cardiac chambers size and function were similar between groups at baseline. HIIT reduced heart rate (55 ± 8 vs. 51 ± 7 bpm; p= 0.003), systolic blood pressure (SBP; 121 ± 11 vs 118 ± 9 mmHg; p = 0.01), mean arterial pressure (MAP; 90 ± 8 vs 89 ± 6 mmHg; p = 0.03) and pulse pressure (52 ± 6 vs 49 ± 5 mmHg; p = 0.01), irrespective of training intensity. Left atrium (LA) volumes increased after HIIT (maximal: 50 ± 14 vs 54 ±14 ml; p= 0.02; minimal: 15 ± 5 vs 20 ± 8 ml; p = 0.01) in both groups. Right ventricle (RV) global longitudinal strain lowered after training in the HIIT85 group only (20 ± 4 vs. 17 ± 3%, p = 0.04). In endurance-trained males, six weeks of HIIT reduce SBP and MAP and increase LA volumes irrespective of training intensity, whereas submaximal HIIT deteriorates RV systolic function.Key pointsHigh-intensity interval training improves physical performance of endurance athletes, although studies examining its cardiovascular effects are sparse.We evaluated the impact of submaximal (85% maximal aerobic power) and supramaximal (115% maximal aerobic power) high-intensity interval training on ambulatory blood pressure, heart rate and cardiac cavities size and function in endurance-trained adults.Irrespective of training intensity, six weeks of high-intensity interval training increase left atrial volumes in endurance-trained adults, whereas the submaximal training decreases right ventricular systolic function.These results may help identify the exercise threshold for potential toxicity of intense exercise training for at-risk individuals and ideal exercise training regimens conferring optimal cardiovascular protection and adapted endurance training for athletes.

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