Variability in Power Output During Cycling in International Olympic-Distance Triathlon

2014 ◽  
Vol 9 (4) ◽  
pp. 732-734 ◽  
Author(s):  
Naroa Etxebarria ◽  
Shaun D’Auria ◽  
Judith M. Anson ◽  
David B. Pyne ◽  
Richard A. Ferguson
Keyword(s):  
Body Mass ◽  
Power Output ◽  
Coefficient Of Variation ◽  
Aerobic Power ◽  
Maximal Aerobic Power ◽  
Mean Power ◽  
Large Power ◽  
Elite Level ◽  
The Mean ◽  
Mean Power Output

Purpose:The patterns of power output in the ~1-h cycle section of Olympic-distance triathlon races are not well documented. Here the authors establish a typical cycling-race profile derived from several International Triathlon Union elite-level draftinglegal triathlon races.Methods:The authors collated 12 different race power profiles from elite male triathletes (N = 5, age 25 ± 5 y, body mass 65.5 ± 5.6 kg; mean ± SD) during 7 international races. Power output was recorded using SRM cranks and analyzed with proprietary software.Results:The mean power output was 252 ± 33 W, or 3.9 ± 0.5 W/kg in relative terms, with a coefficient of variation of 71% ± 13%. Normalized power (power output an athlete could sustain if intensity were maintained constant without any variability) for the entire cycle section was 291 ± 29 W, or 40 ± 13 W higher than the actual mean power output. There were 34 ± 14 peaks of power output above 600 W and ~18% time spent at >100% of maximal aerobic power.Conclusion:Cycling during Olympic-distance triathlon, characterized by frequent and large power variations including repeat supramaximal efforts, equates to a higher workload than cycling at constant power.

scholarly journals An Analysis of Variability in Power Output During Indoor and Outdoor Cycling Time Trials

2019 ◽  
Vol 14 (9) ◽  
pp. 1273-1279 ◽  
Author(s):  
Owen Jeffries ◽  
Mark Waldron ◽  
Stephen D. Patterson ◽  
Brook Galna
Keyword(s):  
Power Output ◽  
Time Trial ◽  
Mean Power ◽  
Portable Power ◽  
Output Variability ◽  
Competitive Cyclists ◽  
The Mean ◽  
Mean Power Output ◽  
Testing Protocols ◽  
Indoor And Outdoor

Purpose: Regulation of power output during cycling encompasses the integration of internal and external demands to maximize performance. However, relatively little is known about variation in power output in response to the external demands of outdoor cycling. The authors compared the mean power output and the magnitude of power-output variability and structure during a 20-min time trial performed indoors and outdoors. Methods: Twenty male competitive cyclists ( 60.4 [7.1] mL·kg−1·min−1) performed 2 randomized maximal 20-min time-trial tests: outdoors at a cycle-specific racing circuit and indoors on a laboratory-based electromagnetically braked training ergometer, 7 d apart. Power output was sampled at 1 Hz and collected on the same bike equipped with a portable power meter in both tests. Results: Twenty-minute time-trial performance indoor (280 [44] W) was not different from outdoor (284 [41] W) (P = .256), showing a strong correlation (r = .94; P < .001). Within-persons SD was greater outdoors (69 [21] W) than indoors (33 [10] W) (P < .001). Increased variability was observed across all frequencies in data from outdoor cycling compared with indoors (P < .001) except for the very slowest frequency bin (<0.0033 Hz, P = .930). Conclusions: The findings indicate a greater magnitude of variability in power output during cycling outdoors. This suggests that constraints imposed by the external environment lead to moderate- and high-frequency fluctuations in power output. Therefore, indoor testing protocols should be designed to reflect the external demands of cycling outdoors.

scholarly journals The Aerobic and Anaerobic Contribution During Repeated 30-s Sprints in Elite Cyclists

2021 ◽  
Vol 12 ◽  
Author(s):  
Nicki Winfield Almquist ◽  
Øyvind Sandbakk ◽  
Bent R. Rønnestad ◽  
Dionne Noordhof
Keyword(s):  
Power Output ◽  
Aerobic Power ◽  
Anaerobic Power ◽  
High Volume ◽  
Mean Power ◽  
Training Camp ◽  
Mean Power Output ◽  
Aerobic And Anaerobic ◽  
Elite Cyclists ◽  
Sprint Ability

Although the ability to sprint repeatedly is crucial in road cycling races, the changes in aerobic and anaerobic power when sprinting during prolonged cycling has not been investigated in competitive elite cyclists. Here, we used the gross efficiency (GE)-method to investigate: (1) the absolute and relative aerobic and anaerobic contributions during 3 × 30-s sprints included each hour during a 3-h low-intensity training (LIT)-session by 12 cyclists, and (2) how the energetic contribution during 4 × 30-s sprints is affected by a 14-d high-volume training camp with (SPR, n = 9) or without (CON, n = 9) inclusion of sprints in LIT-sessions. The aerobic power was calculated based on GE determined before, after sprints, or the average of the two, while the anaerobic power was calculated by subtracting the aerobic power from the total power output. When repeating 30-s sprints, the mean power output decreased with each sprint (p &lt; 0.001, ES:0.6–1.1), with the majority being attributed to a decrease in mean anaerobic power (first vs. second sprint: −36 ± 15 W, p &lt; 0.001, ES:0.7, first vs. third sprint: −58 ± 16 W, p &lt; 0.001, ES:1.0). Aerobic power only decreased during the third sprint (first vs. third sprint: −17 ± 5 W, p &lt; 0.001, ES:0.7, second vs. third sprint: 16 ± 5 W, p &lt; 0.001, ES:0.8). Mean power output was largely maintained between sets (first set: 786 ± 30 W vs. second set: 783 ± 30 W, p = 0.917, ES:0.1, vs. third set: 771 ± 30 W, p = 0.070, ES:0.3). After a 14-d high-volume training camp, mean power output during the 4 × 30-s sprints increased on average 25 ± 14 W in SPR (p &lt; 0.001, ES:0.2), which was 29 ± 20 W more than CON (p = 0.008, ES: 0.3). In SPR, mean anaerobic power and mean aerobic power increased by 15 ± 13 W (p = 0.026, ES:0.2) and by 9 ± 6 W (p = 0.004, ES:0.2), respectively, while both were unaltered in CON. In conclusion, moderate decreases in power within sets of repeated 30-s sprints are primarily due to a decrease in anaerobic power and to a lesser extent in aerobic power. However, the repeated sprint-ability (multiple sets) and corresponding energetic contribution are maintained during prolonged cycling in elite cyclists. Including a small number of sprints in LIT-sessions during a 14-d training camp improves sprint-ability mainly through improved anaerobic power.

Reduced neuromuscular activity and force generation during prolonged cycling

2001 ◽  
Vol 281 (1) ◽  
pp. R187-R196 ◽  
Author(s):  
A. St Clair Gibson ◽  
E. J. Schabort ◽  
T. D. Noakes
Keyword(s):  
Power Output ◽  
High Intensity ◽  
Voluntary Contraction ◽  
Active Muscle ◽  
Mean Power ◽  
Variable Intensity ◽  
Neuromuscular Activity ◽  
Integrated Emg ◽  
The Mean ◽  
Mean Power Output

We examined neuromuscular activity during stochastic (variable intensity) 100-km cycling time trials (TT) and the effect of dietary carbohydrate manipulation. Seven endurance-trained cyclists performed two 100-km TT that included five 1-km and four 4-km high-intensity epochs (HIE) during which power output, electromyogram (EMG), and muscle glycogen data were analyzed. The mean power output of the 4-km HIE decreased significantly throughout the trial from 319 ± 48 W for the first 4-km HIE to 278 ± 39 W for the last 4-km HIE ( P < 0.01). The mean integrated EMG (IEMG) activity during the first 4-km HIE was 16.4 ± 9.8% of the value attained during the pretrial maximal voluntary contraction (MVC). IEMG decreased significantly throughout the trial, reaching 11.1 ± 5.6% during the last 4-km HIE ( P < 0.01). The study establishes that neuromuscular activity in peripheral skeletal muscle falls parallel with reduction in power output during bouts of high-intensity exercise. These changes occurred when <20% of available muscle was recruited and suggest the presence of a central neural governor that reduces the active muscle recruited during prolonged exercise.

Measuring the Effect of Vegetated Roofs on the Performance of Photovoltaic Panels in a Combined System

2016 ◽  
Vol 138 (6) ◽  
Author(s):  
Hamid Ogaili ◽  
David J. Sailor
Keyword(s):  
Power Output ◽  
Green Roof ◽  
Transfer Coefficients ◽  
Combined System ◽  
Mean Power ◽  
Black And White ◽  
Heat Transfer Coefficients ◽  
Vegetated Roofs ◽  
The Mean ◽  
Mean Power Output

Experiments were conducted in summer using two identical photovoltaic (PV) panels at two heights using three roofing types: white, black, and green (vegetated). For experiments at an 18 cm height, the mean power output of the PV-green roof system was 1.2% and 0.8% higher than the PV-black and PV-white roofs, respectively. At a 24 cm height, the benefit of the green roof was slightly diminished with power output for the PV above a green roof being 1.0% and 0.7% higher than the black and white roof experiments, respectively. These results were consistent with measured variations in mean panel surface temperatures; the green roof systems were generally cooler by 1.5–3 °C. A unique aspect of this research is the investigation into the effect of vegetation on the convective cooling of the PV panels. Panel heat transfer coefficients for the PV-green roof were 10–20% higher than for the white and black roof configurations, suggesting a mixing benefit associated with the roughness of the plant canopy. While the best PV performance was obtained by locating PV above a green roof, the relative benefits diminish with distance between the PV and the roof.

Dietary carbohydrate, muscle glycogen, and power output during rowing training

1991 ◽  
Vol 70 (4) ◽  
pp. 1500-1505 ◽  
Author(s):  
J. C. Simonsen ◽  
W. M. Sherman ◽  
D. R. Lamb ◽  
A. R. Dernbach ◽  
J. A. Doyle ◽  
...  
Keyword(s):  
Body Mass ◽  
Muscle Glycogen ◽  
Power Output ◽  
Glycogen Content ◽  
Dietary Carbohydrate ◽  
Mean Power ◽  
Muscle Glycogen Content ◽  
High Carbohydrate ◽  
Peak Vo2 ◽  
Mean Power Output

The belief that high-carbohydrate diets enhance training capacity (mean power output) has been extrapolated from studies that have varied dietary carbohydrate over a few days and measured muscle glycogen but did not assess power output during training. We hypothesized that a high-carbohydrate (HI) diet (10 g.kg body mass-1.day-1) would promote greater muscle glycogen content and greater mean power output during training than a moderate-carbohydrate (MOD) diet (5 g.kg body mass-1.day-1) over 4 wk of intense twice-daily rowing training. Dietary protein intake was 2 g.kg body mass-1.day-1, and fat intake was adjusted to maintain body mass. Twelve male and 10 female collegiate rowers were randomly assigned to the treatment groups. Training was 40 min at 70% peak O2 consumption (VO2) (A.M.) and either three 2,500-m time trials to assess power output or interval training at 70-90% peak VO2 (P.M.). Mean daily training was 65 min at 70% peak VO2 and 38 min at greater than or equal to 90% peak VO2. Mean muscle glycogen content increased 65% in the HI group (P less than 0.05) but remained constant at 119 mmol/kg in the MOD group over the 4 wk. Mean power output in time trials increased 10.7 and 1.6% after 4 wk in the HI and MOD groups, respectively (P less than 0.05). We conclude that a diet with 10 g carbohydrate.kg body mass-1.day-1 promotes greater muscle glycogen content and greater power output during training than a diet containing 5 g carbohydrate.kg body mass-1.day-1 over 4 wk of intense twice-daily rowing training.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Eccentric-concentric Ratio: A Key Factor for Defining Strength Training in Soccer

2019 ◽  
Vol 40 (12) ◽  
pp. 796-802 ◽  
Author(s):  
F. Javier Nuñez ◽  
Moisés de Hoyo ◽  
Alejandro Muñoz López ◽  
Borja Sañudo ◽  
Carlos Otero-Esquina ◽  
...  
Keyword(s):  
Strength Training ◽  
Power Output ◽  
Soccer Players ◽  
Control Group ◽  
Mean Power ◽  
Key Factor ◽  
The Mean ◽  
And Performance ◽  
Mean Power Output ◽  
Experimental Group

AbstractThe aims of this study were to analyse the effect of chronic strength training over concentric power (CON), eccentric power (ECC), ECC/CON ratio, and 20 m linear sprint performance in elite young soccer players. Twenty young elite Spanish soccer players were assigned to an experimental group (CPG) which performed a front-step exercise using a conical pulley, 2–3 sets of 6 repetitions each leg, during 9 weeks (CPG, n=10) in addition to its usual strength training, or to a control group (CG, n=10). The improvements in the ECC mean power (36%, ES=1.61), and ECC / CON ratio (17%, ES=1.77) were substantially greater in the CPG than in the CG while the CON mean power (16%, ES=0.83) was substantially greater in the CG than in the CPG. The sprinting time for 10 m (2.8%, ES=0.78) and the 10 m flying time between 10–20 m (1.72%, ES=0.41) were substantially enhanced in CPG and CG respectively. To be efficient when defining a functional strength training and performance increments using an inertial device, the mean power output need to be measured during the CON and ECC phases and an analysis of the ECC / CON ratio should be included.

scholarly journals PPeak oxygen uptake differentiates competitive from recreational male surfboard riders

Motricidade ◽  
2018 ◽  
Vol 13 (4) ◽  
pp. 39
Author(s):  
Nuno Almeida ◽  
Joana Reis ◽  
João Beckert ◽  
Miguel Moreira ◽  
Francisco Alves
Keyword(s):  
Oxygen Uptake ◽  
Body Mass ◽  
Power Output ◽  
Aerobic Power ◽  
Ventilatory Threshold ◽  
Peak Oxygen Uptake ◽  
Maximal Aerobic Power ◽  
Compensation Point ◽  
Respiratory Compensation Point ◽  
Respiratory Compensation

The purpose of this study was to verify if competitive performance status was associated to different levels of specific aerobic fitness in Portuguese surfboard riders. Six recreational surfers (age: 32.3±3.1 years; body mass: 73.2±7.8kg; height: 1.75±0.05m) and six competitive international level surfers (age: 25±8.4years; body mass: 68.5±3.8kg; height: 1.74±0.05m) performed a maximal continuous incremental paddling test consisting of two-minute steps starting at 20W, with increments of 10W, for determination of peak oxygen uptake and maximal aerobic power. Ventilatory threshold and respiratory compensation point with corresponding heart rate and power output were also determined. Elite surfers presented higher values for peak oxygen uptake (43.6±7.9 ml.kg-1.min-1) than recreational surfers (31.1±7.4 ml.kg-1.min-1, p=0.01) however, there were no differences (p> 0.05) between groups for maximal aerobic power (elite: 76.6±18.6W; recreational: 76.6±16.6W). No significant differences between the power output at which ventilatory threshold or respiratory compensation point occurred but elite surfers reached ventilation threshold with 22.5±5.8 ml.kg-1.min-1 which was significantly higher than recreational surfers (16±3.7 ml.kg-1.min-1). These findings show that elite surfers have higher values of peak oxygen uptake than recreational surfers which suggest a higher aerobic adaptation that may be related to the different amount of exercise volume undertaken.

Body Size and the Growth of Maximal Aerobic Power in Children: A Longitudinal Analysis

1997 ◽  
Vol 9 (3) ◽  
pp. 262-274 ◽  
Author(s):  
Thomas Rowland ◽  
Paul Vanderburgh ◽  
Lee Cunningham
Keyword(s):  
Gender Differences ◽  
Body Size ◽  
Body Mass ◽  
Allometric Scaling ◽  
Aerobic Power ◽  
Maximal Aerobic Power ◽  
Scaling Exponent ◽  
Cross Sectional ◽  
Treadmill Testing ◽  
The Mean

Adjustment of VO2max for changes in body size is important in evaluating aerobic fitness in children. It is important, therefore, to understand the normal relationship between changes VO2max and body size during growth. Over the course of 5 years, 20 children (11 boys, 9 girls) underwent annual maximal treadmill testing to determine VO2max. The mean longitudinal allometric scaling exponent for VO2max relative to body mass (M) was 1.10 ± 0.30 in the boys and 0.78 ± 0.28 in the girls (p < .05). Respective cross-sectional values were 0.53 ± 0.08 and 0.65 ± 0.03. VO2max expressed relative to M1.0, M0.75, and M0.67 rose during the 5 years in the boys, but not the girls. Significant gender differences remained when VO2max was related to lean body mass. These findings suggest (a) factors other than body size affect the development of VO2max in children, and (b) gender differences exist in VO2max during childhood which are independent of body composition.

scholarly journals Effects of Acute Caffeine Intake on Power Output and Movement Velocity During a Multiple-Set Bench Press Exercise Among Mild Caffeine Users

2021 ◽  
Vol 78 (1) ◽  
pp. 219-228
Author(s):  
Aleksandra Filip-Stachnik ◽  
Michal Krzysztofik ◽  
Magdalena Kaszuba ◽  
Katarzyna Leznicka ◽  
Maciej Kostrzewa ◽  
...  
Keyword(s):  
Body Mass ◽  
Power Output ◽  
Bench Press ◽  
Peak Power Output ◽  
Caffeine Intake ◽  
Mean Power ◽  
Acute Dose ◽  
Main Effect ◽  
Bar Velocity ◽  
Mean Power Output

Abstract The main goal of this study was to evaluate the effectiveness of an acute dose of caffeine (6 mg/kg body mass (b.m.)) on power output and bar velocity during a bench press multiple-set resistance training session in participants with mild daily caffeine consumption (in the range of 1 to 3 mg/kg/b.m). Thirteen recreationally active male participants (age: 21.9 ± 1.2 years, body mass: 74.4 ± 5.3 kg, body mass index: 23.1 ± 1.6 kg/m2, bench press onerepetition maximum (1RM): 79.2 ± 14.9 kg), with daily caffeine ingestion of 1.56 ± 0.56 mg/kg/b.m., participated in the study with a randomized double-blind experimental design. Each participant performed two identical experimental sessions, 60 min after the intake of a placebo (PLAC) or 6 mg/kg/b.m. of caffeine (CAF-6). In each experimental session, participants performed 5 sets of 5 repetitions of the bench press exercise with a load equivalent to 70% 1RM. The eccentric and concentric phases of the bench press exercise were performed at maximal possible velocity in each repetition. Bar velocity was recorded with a linear position transducer and power output was calculated using velocity and load data. A two-way repeated measures ANOVA indicated no significant substance x set interaction for mean power output (MP), mean bar velocity (MV), peak power output (PP) and peak bar velocity (PV). However, there was a significant main effect of substance on MP (p < 0.01; η2 = 0.47) and MV (p < 0.01; η2 =0.45). Post hoc analysis for main effect revealed that MP and MV values in the CAF-6 group were higher than in the PLAC group in all 5 sets of the exercise (p < 0.05). In conclusion, this study demonstrated that an acute dose of caffeine before resistance exercise increased mean power output and mean bar velocity during a multiple-set bench press exercise protocol among mild caffeine users.

Power Output During a Professional Men’s Road-Cycling Tour

2006 ◽  
Vol 1 (4) ◽  
pp. 324-335 ◽  
Author(s):  
Tammie R. Ebert ◽  
David T. Martin ◽  
Brian Stephens ◽  
Robert T. Withers
Keyword(s):  
Power Output ◽  
Aerobic Power ◽  
Interval Training ◽  
Mean Power ◽  
Race Time ◽  
Maximum Aerobic Power ◽  
Road Cycling ◽  
Graded Exercise ◽  
Mean Power Output ◽  
Aerobic Power Output

Purpose:To quantify the power-output demands of men’s road-cycling stage racing using a direct measure of power output.Methods:Power-output data were collected from 207 races over 6 competition years on 31 Australian national male road cyclists. Subjects performed a maximal graded exercise test in the laboratory to determine maximum aerobic-power output, and bicycles were fitted with SRM power meters. Races were described as fl at, hilly, or criterium, and linear mixed modeling was used to compare the races.Results:Criterium was the shortest race and displayed the highest mean power output (criterium 262 ± 30 v hilly 203 ± 32 v fl at 188 ± 30 W), percentage total race time above 7.5 W/kg (crite-rium 15.5% ± 4.1% v hilly 3.8% ± 1.7% v fl at 3.5% ± 1.4%) and SD in power output (criterium 250 v hilly 165 v fl at 169 W). Approximately 67%, 80%, and 85% of total race time was spent below 5 W/kg for criterium, hilly and fl at races, respectively. About 70, 40, and 20 sprints above maximum aerobic-power output occurred during criterium, hilly, and fl at races, respectively, with most sprints being 6 to 10 s.Conclusions:These data extend previous research documenting the demands of men’s road cycling. Despite the relatively low mean power output, races were characterized by multiple high-intensity surges above maximum aerobic-power output. These data can be used to develop sport-specific interval-training programs that replicate the demands of competition.

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