scholarly journals Energy Expenditure Equation Choice: Effects on Cycling Efficiency and its Reliability

2020 ◽  
Vol 15 (2) ◽  
pp. 288-291
Author(s):  
Arthur H. Bossi ◽  
Wouter P. Timmerman ◽  
James G. Hopker
Keyword(s):  
Energy Expenditure ◽  
Peak Power ◽  
Peak Power Output ◽  
Physiological Profile ◽  
Gas Exchanges ◽  
Gross Efficiency ◽  
Reliability Parameters ◽  
Cycling Efficiency ◽  
The Mean ◽  
Gas Exchange Threshold

Purpose: There are several published equations to calculate energy expenditure (EE) from gas exchanges. The authors assessed whether using different EE equations would affect gross efficiency (GE) estimates and their reliability. Methods: Eleven male and 3 female cyclists (age 33 [10] y; height: 178 [11] cm; body mass: 76.0 [15.1] kg; maximal oxygen uptake: 51.4 [5.1] mL·kg−1·min−1; peak power output: 4.69 [0.45] W·kg−1) completed 5 visits to the laboratory on separate occasions. In the first visit, participants completed a maximal ramp test to characterize their physiological profile. In visits 2 to 5, participants performed 4 identical submaximal exercise trials to assess GE and its reliability. Each trial included three 7-minute bouts at 60%, 70%, and 80% of the gas exchange threshold. EE was calculated with 4 equations by Péronnet and Massicotte, Lusk, Brouwer, and Garby and Astrup. Results: All 4 EE equations produced GE estimates that differed from each other (all P < .001). Reliability parameters were only affected when the typical error was expressed in absolute GE units, suggesting a negligible effect—related to the magnitude of GE produced by each EE equation. The mean coefficient of variation for GE across different exercise intensities and calculation methods was 4.2%. Conclusions: Although changing the EE equation does not affect GE reliability, exercise scientists and coaches should be aware that different EE equations produce different GE estimates. Researchers are advised to share their raw data to allow for GE recalculation, enabling comparison between previous and future studies.

Sprinting for the Win: Distribution of Power Output in Women’s Professional Cycling

2018 ◽  
Vol 13 (9) ◽  
pp. 1237-1242 ◽  
Author(s):  
Jeremiah J. Peiffer ◽  
Chris R. Abbiss ◽  
Eric C. Haakonssen ◽  
Paolo Menaspà
Keyword(s):  
Power Output ◽  
Peak Power ◽  
Peak Power Output ◽  
Maximal Power Output ◽  
Variable Nature ◽  
The Mean ◽  
Road Cyclists ◽  
Distribution Of Power ◽  
Power Outputs ◽  
Professional Cycling

Purpose:To examine the power-output distribution and sprint characteristics of professional female road cyclists.Methods:A total of 31 race files, representing top 5 finishes, were collected from 7 professional female cyclists. Files were analyzed for sprint characteristics, including mean and peak power output, velocity, and duration. The final 20 min before the sprint was analyzed to determine the mean maximal power output (MMP) consistent with durations of 5, 15, 30, 60, 240, and 600 s. Throughout the race, the number of efforts for each duration exceeding 80% of its corresponding final 20-min MMP (MMP80) was determined. The number of 15-s efforts exceeding 80% of the mean final sprint power output (MSP80) was determined.Results:Sprint finishes lasted 21.8 (6.7) s with mean and peak power outputs of 679 (101) and 886 (91) W, respectively. Throughout the race, additional 5-, 15-, and 30-s efforts above MMP80were completed in the 5th compared with the 1st–4th quintiles of the race. The 60-s efforts were greater during the 5th quintile compared with the 1st, 2nd, and 4th quintiles, and during the 3rd compared with the 4th quintile. More 240-s efforts were recorded during the 5th compared with the 1st and 4th quintiles. About 82% of the 15-s efforts above MSP80were completed in the 2nd, 3rd, and 5th quintiles of the race.Conclusions:These data demonstrate the variable nature of women’s professional cycling and the physical demands necessary for success, thus providing information that could enhance in-race decision making and the development of race-specific training programs.

scholarly journals Indoor Cycling Energy Expenditure: Does Sequence Matter?

2021 ◽  
Vol 18 (3) ◽  
pp. 870 ◽  
Author(s):  
Cristina Cortis ◽  
Andrea Fusco ◽  
Mitchell Cook ◽  
Scott T. Doberstein ◽  
Cordial Gillette ◽  
...  
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Energy Expenditure ◽  
Peak Power ◽  
Perceived Exertion ◽  
Recovery Period ◽  
Rating Of Perceived Exertion ◽  
Peak Power Output ◽  
Exercise Enjoyment ◽  
Physiological Markers

Although cycling class intensity can be modified by changing interval intensity sequencing, it has not been established whether the intensity order can alter physiological and perceptual responses. Therefore, this study aimed to determine the effects of interval intensity sequencing on energy expenditure (EE), physiological markers, and perceptual responses during indoor cycling. Healthy volunteers (10 males = 20.0 ± 0.8years; 8 females = 21.3 ± 2.7years) completed three randomly ordered interval bouts (mixed pyramid—MP, ascending intervals—AI, descending intervals—DI) including three 3-min work bouts at 50%, 75%, and 100% of peak power output (PPO) and three 3-min recovery periods at 25% PPO. Heart rate (HR) and oxygen consumption (VO2) were expressed as percentages of maximal HR (%HRmax) and VO2 (%VO2max). EE was computed for both the work bout and for the 5-min recovery period. Session Rating of Perceived Exertion (sRPE) and Exercise Enjoyment Scale (EES) were recorded. No differences emerged for % HRmax (MP = 73.3 ± 6.1%; AI = 72.1 ± 4.9%; DI = 71.8 ± 4.5%), % VO2max (MP = 51.8 ± 4.6%; AI = 51.4 ± 3.9%; DI = 51.3 ± 4.5%), EE (MP = 277.5 ± 39.9 kcal; AI = 275.8 ± 39.4 kcal; DI = 274.9 ± 42.1 kcal), EES (MP = 4.9 ± 1.0; AI = 5.3 ± 1.1; DI = 4.9 ± 0.9), and sRPE (MP = 4.9 ± 1.0; AI = 5.3 ± 1.1; DI = 4.9 ± 0.9). EE during recovery was significantly (p < 0.005) lower after DI (11.9 ± 3.2 kcal) with respect to MP (13.2 ± 2.5 kcal) and AI (13.3 ± 2.5 kcal). Although lower EE was observed during recovery in DI, interval intensity sequencing does not affect overall EE, physiological markers, and perceptual responses.

scholarly journals The Effect of Different Cadence on Paddling Gross Efficiency and Economy in Stand-Up Paddle Boarding

2020 ◽  
Vol 17 (13) ◽  
pp. 4893
Author(s):  
Arkaitz Castañeda-Babarro ◽  
Jordan Santos-Concejero ◽  
Aitor Viribay ◽  
Borja Gutiérrez-Santamaría ◽  
Juan Mielgo-Ayuso
Keyword(s):  
Energy Efficiency ◽  
Oxygen Uptake ◽  
Peak Power ◽  
Respiratory Exchange Ratio ◽  
Endurance Performance ◽  
Test Session ◽  
Peak Power Output ◽  
Physiological Variables ◽  
Incremental Exercise Test ◽  
Gross Efficiency

Background: Due to the importance of energy efficiency and economy in endurance performance, it is important to know the influence of different paddling cadences on these variables in the stand-up paddleboarding (SUP). The purpose of this study was to determine the effect of paddling at different cadences on the energy efficiency, economy, and physiological variables of international SUP race competitors. Methods: Ten male paddlers (age 28.8 ± 11.0 years; height 175.4 ± 5.1 m; body mass 74.2 ± 9.4 kg) participating in international tests carried out two test sessions. In the first one, an incremental exercise test was conducted to assess maximal oxygen uptake and peak power output (PPO). On the second day, they underwent 3 trials of 8 min each at 75% of PPO reached in the first test session. Three cadences were carried out in different trials randomly assigned between 45–55 and 65 strokes-min−1 (spm). Heart rate (HR), blood lactate, perceived sense of exertion (RPE), gross efficiency, economy, and oxygen uptake (VO2) were measured in the middle (4-min) and the end (8-min) of each trial. Results: Economy (45.3 ± 5.7 KJ·l−1 at 45 spm vs. 38.1 ± 5.3 KJ·l−1 at 65 spm; p = 0.010) and gross efficiency (13.4 ± 2.3% at 45 spm vs. 11.0 ± 1.6% at 65 spm; p = 0.012) was higher during de 45 spm condition than 65 spm in the 8-min. Respiratory exchange ratio (RER) presented a lower value at 4-min than at 8-min in 55 spm (4-min, 0.950 ± 0.065 vs. 8-min, 0.964 ± 0.053) and 65 spm cadences (4-min, 0.951 ± 0.030 vs. 8-min, 0.992 ± 0.047; p < 0.05). VO2, HR, lactate, and RPE were lower (p < 0.05) at 45 spm (VO2, 34.4 ± 6.0 mL·kg−1·min−1; HR, 161.2 ± 16.4 beats·min−1; lactate, 3.5 ± 1.0 mmol·l−1; RPE, 6.0 ± 2.1) than at 55 spm (VO2, 38.6 ± 5.2 mL·kg−1·min−1; HR, 168.1 ± 15.1 beats·min−1; lactate, 4.2 ± 1.2 mmol·l−1; RPE, 6.9 ± 1.4) and 65 spm (VO2, 38.7 ± 5.9 mL·kg−1·min−1; HR, 170.7 ± 13.0 beats·min−1; 5.3 ± 1.8 mmol·l−1; RPE, 7.6 ± 1.4) at 8-min. Moreover, lactate and RPE at 65 spm was greater than 55 spm (p < 0.05) at 8-min. Conclusion: International male SUP paddlers were most efficient and economical when paddling at 45 spm vs. 55 or 65 spm, confirmed by lower RPE values, which may likely translate to faster paddling speed and greater endurance.

Factors of Rowing Ergometer Performance in High-Level Female Rowers

2017 ◽  
Vol 38 (13) ◽  
pp. 1023-1028 ◽  
Author(s):  
Muriel Bourdin ◽  
Jean-Rene Lacour ◽  
Charles Imbert ◽  
Laurent Messonnier
Keyword(s):  
Power Output ◽  
Peak Power ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Peak Power Output ◽  
Physiological Factors ◽  
Gross Efficiency ◽  
Rowing Ergometer ◽  
High Level ◽  
Ergometer Test

AbstractThe present study investigated morphological and physiological factors of rowing ergometer performance over 2000 m (P2000, W) in 70 national and international level [27 lightweight (LW) and 43 heavyweight (HW)] female rowers. Maximal oxygen uptake (V̇O2max, L.min−1), maximal aerobic power (Pamax, W), power output corresponding to 4 mmol.L−1 blood lactate concentration expressed in absolute (PLa4, W) and relative to Pamax (PLa4%, %) values, peak power output (Ppeak, W), and rowing gross efficiency (RGE, %) were determined during an incremental rowing test. In the whole group, Ppeak was the best predictor of P2000 (r=0.89, p<0.001), as it was shown in men. PLa4 (r=0.87), V̇O2max (r=0.83), body mass (r=0.65), and height (r=0.64) were also significantly correlated with P2000 (p<0.001 for all). Ppeak was also the best predictor of P2000 when the two sub-groups LW and HW were considered separately. It was concluded that Ppeak is an overall index of physiological rowing capacity in groups of high-level LW and HW female rowers. The predictive value of Ppeak is similar to that of PLa4, but Ppeak presents the advantage of being obtained with a simple ergometer test without biological measurements.

An Approach to Estimating Gross Efficiency During High-Intensity Exercise

2013 ◽  
Vol 8 (6) ◽  
pp. 682-684 ◽  
Author(s):  
Jos J. de Koning ◽  
Dionne A. Noordhof ◽  
Tom P. Uitslag ◽  
Rianna E Galiart ◽  
Christopher Dodge ◽  
...  
Keyword(s):  
High Intensity ◽  
Peak Power ◽  
Power Production ◽  
Submaximal Exercise ◽  
High Intensity Exercise ◽  
Peak Power Output ◽  
Control Test ◽  
Incremental Test ◽  
Gross Efficiency ◽  
Determining Factor

Purpose:Gross efficiency (GE) is coupling power production to propulsion and is an important performance-determining factor in endurance sports. Measuring GE normally requires measuring VO2 during submaximal exercise. In this study a method is proposed to estimating GE during high-intensity exercise.Methods:Nineteen subjects completed a maximal incremental test and 2 GE tests (1 experimental and 1 control test). The GE test consisted of 10 min cycling at 50% peak power output (PPO), 2 min at 25 W, followed by 4 min 100% PPO, 1 min at 25 W, and another 10 min at 50% PPO. GE was determined for the 50%-PPO sections and was, for the second 50%-PPO section, back-extrapolated, using linear regression, to the end of the 100%-PPO bout.Results:Back-extrapolation of the GE data resulted in a calculated GE of 15.8% ± 1.7% at the end of the 100%-PPO bout, in contrast to 18.3% ± 1.3% during the final 2 min of the first 10-min 50%-PPO bout.Conclusion:Back-extrapolation seems valuable in providing more insight in GE during high-intensity exercise.

scholarly journals Peak Power Output in the Bench Pull Is Maximized After Four Weeks of Specific Power Training

2016 ◽  
Vol 30 (4) ◽  
pp. 966-972
Author(s):  
Russell I. Jolley ◽  
Jon E. Goodwin ◽  
Daniel J. Cleather
Keyword(s):  
Power Output ◽  
Peak Power ◽  
Peak Power Output ◽  
Specific Power ◽  
Power Training

Effect of season on thermoregulatory responses and energy expenditure of goats on semi-arid range in India

2002 ◽  
Vol 139 (1) ◽  
pp. 87-93 ◽  
Author(s):  
A. K. SHINDE ◽  
RAGHAVENDRA BHATTA ◽  
S. K. SANKHYAN ◽  
D. L. VERMA
Keyword(s):  
Heart Rate ◽  
Heat Stress ◽  
Solar Radiation ◽  
Energy Expenditure ◽  
Arid Regions ◽  
Physiological Responses ◽  
Face Mask ◽  
Mean Value ◽  
The Mean ◽  
Semi Arid

A study of the physiological responses and energy expenditure of goats was carried out from June 1999 to May 2000 by conducting two experiments: one on bucks maintained on stall feeding in autumn 1999 (Expt 1) followed by year-round grazing on native ranges over three seasons: monsoon, winter and summer (Expt 2). Physiological responses and energy expenditure (EE) measurements of housed and grazing goats were recorded at 06.00 h and 14.00 h for 5 consecutive days in each season. Goats were fixed with a face mask and meteorological balloon for collection of expired air and measurement of EE. Respiration rate (RR) at 06.00 h was similar in all seasons (14 respiration/min) except in the monsoon, where a significantly (P<0.05) higher value (26 respiration/min) was recorded. At 14.00 h, RR was higher in monsoon and summer (81 and 91 respiration/min) than in winter (52 respiration/min). Irrespective of the season, heart rate (HR) was higher at 14.00 h (86 beat/min) than at 06.00 h (64 beat/min). The rise of rectal temperature (RT) from morning (06.00 h) to peak daily temperature (14.00 h) was 0.9 °C in housed goats in autumn and 1.0, 2.1 and 2.0 °C in grazing goats during monsoon, winter and summer, respectively. The mean value was 1.7 °C. Skin temperature (ST) was lowest in winter (30.1 °C) and highest at 14.00 h in summer (40.3 °C). Energy expenditure of goats at 06.00 h was 32.7 W in winter and significantly (P<0.05) increased to 52.0 W in summer and 107.8 W in monsoon. At 14.00 h, EE was 140.2 W in winter and increased to 389.0 W and 391.3 W respectively in monsoon and summer. It is concluded that monsoon and summer are both stressful seasons in semi-arid regions. Animals should be protected from direct solar radiation during the hottest hours of the day to ameliorate the effect of heat stress.

Effects of an Off-Site Walking Program on Energy Expenditure, Serum Lipids, and Glucose Metabolism in Middle-Aged Women

2003 ◽  
Vol 4 (3) ◽  
pp. 181-192 ◽  
Author(s):  
Fumiko Furukawa ◽  
Keiko Kazuma ◽  
Masako Kawa ◽  
Mitsunori Miyashita ◽  
Kyohko Niiro ◽  
...  
Keyword(s):  
Energy Expenditure ◽  
Nurse Managers ◽  
Intervention Group ◽  
Density Lipoprotein ◽  
Control Group ◽  
Middle Aged ◽  
Walking Program ◽  
Before And After ◽  
The Mean ◽  
Blood Profiles

The present study aims to identify the effects of systematic walking on exercise energy expenditure (EEE) and blood profiles in middle-aged women. Fifty-two female nurse managers, aged 32 to 57 years (42.0 ± 6.2), were randomly assigned to an intervention group (IG) and a control group (CG) for a 12-week study of the walking program. EEE was measured using a microelectronic device. Blood profiles were assessed before and after the walking program. The mean EEE (kcal/kg/d) in the IG and CG was 4.73 ± 1.02 and 3.88 ± 0.81 ( P = 0.01), indicating an increase of 1.17 ± 0.98 and 0.46 ± 0.68 from baseline ( P = 0.01), respectively. The mean change in high-density lipoprotein cholesterol in the IG and CG was 1.8 ± 8.3 mg/dL and −2.9 ± 7.0 mg/dL ( P = 0.051); that in insulin was −4.5 ± 7.5 μU/dL and −0.6 ± 4.3 μU/dL ( P = 0.046), respectively. These results show that systematic walking increases EEE and improves blood profiles.

Abstract P134: Preliminary Data: Dietary Nitrate Supplementation Does Not Extend Dry Static Apnea Or Wingate Performance

Circulation ◽  
2021 ◽  
Vol 143 (Suppl_1) ◽  
Author(s):  
Colin Carriker ◽  
Phillip Armentrout ◽  
Sarah Levine ◽  
James Smoliga
Keyword(s):  
Power Output ◽  
Preliminary Data ◽  
Repeated Measures ◽  
Peak Power ◽  
Hold Time ◽  
Wingate Test ◽  
Peak Power Output ◽  
Breath Hold ◽  
Dietary Nitrate ◽  
Nitrate Supplementation

Introduction: Previous studies have examined dietary nitrate supplementation and its effects on dry static apnea, and peak power. Dietary nitrate supplementation has been found to increase maximal apnea and peak power output. The purpose of this study was to determine the effects of beetroot juice on dry static apnea and Wingate performance. Hypothesis: Dietary nitrate will improve maximal breath hold time and peak power output. Dietary nitrate will improve tolerance to CO2, thereby improving maximal breath hold time and anaerobic capacity. Methods: In a randomized, double-blind, counterbalanced study, five healthy males (20.4±0.89 years) visited the lab on 3 separate occasions each separated by one week. Visit 1 served as a Wingate and breath hold familiarization visit. Prior to visits 2 and 3 participants were instructed to drink a beverage either a placebo (negligible nitrate content, PL) or dietary nitrate rich beverage (12.4 mmol nitrate, NIT) during the 4 days leading up to their next visit. Visits 2 and 3 consisted of two submaximal breath holds (80% of maximal determined during visit 1), with 2 minutes of rest between and three minutes of rest preceding the final breath hold for maximal duration. Finally, participants completed a standardized 10-minute warmup on the cycle ergometer before completing a 30-second maximal effort Wingate test. Results: A linear mixed effects model was used to determine whether treatment (NIT vs. PL) was associated with differences in VCO2 or PetCO2. Time (0, 10, 20, 30 min post-breath hold) and Treatment both served as repeated measures. Models were developed using multiple repeated measures covariance matrix structures, and the model with the lowest AIC was chosen as the final model. The interaction between time and treatment was included in the original models, and was removed if it was not statistically significant. Time was a statistically significant factor for VCO2 and PetCO2 (p < 0.001). Treatment, and the Time x Treatment interaction was not significant for either variable. No differences between NIT and PL were observed during the Wingate test for either time to peak power (5.02±2.45 and 6.2±2.43 sec, respectively) or maximal power (9.73±1.01 and 9.72±1.03 watts/kg, respectively) and fatigue index (49.42±14.98 and 47.30±6.99 watts/sec, respectively). Conclusion: Preliminary data indicates that in a general population four days of dietary nitrate supplementation may not improve breath hold time, tolerance to carbon dioxide in the lungs, or Wingate performance.

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.

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