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 Functional Threshold Power in Cyclists: Validity of the Concept and Physiological Responses

2018 ◽  
Vol 39 (10) ◽  
pp. 737-742 ◽  
Author(s):  
Fernando Borszcz ◽  
Artur Tramontin ◽  
Arthur Bossi ◽  
Lorival Carminatti ◽  
Vitor Costa
Keyword(s):  
Power Output ◽  
Time Trial ◽  
Threshold Power ◽  
Time To Exhaustion ◽  
Mean Power ◽  
Incremental Test ◽  
Individual Anaerobic Threshold ◽  
The Mean ◽  
The Individual ◽  
Mean Power Output

AbstractFunctional threshold power is defined as the highest power output a cyclist can maintain in a quasi-steady state for approximately 60 min (FTP60). In order to improve practicality for regular evaluations, FTP60 could theoretically be determined as 95% of the mean power output in a 20-min time trial (FTP20). This study tested this assumption and the validity of FTP20 and FTP60 against the individual anaerobic threshold (IAT). Twenty-three trained male cyclists performed an incremental test to exhaustion, 20- and 60-min time trials, and a time to exhaustion at FTP20. Power output, heart rate and oxygen uptake representing FTP20, FTP60 and IAT were not different (p>0.05), and large to very large correlations were found (r=0.61 to 0.88). Bland-Altman plots between FTP20, FTP60 and IAT showed small bias (–1 to –5 W), but large limits of agreement ([–40 to 32 W] to [–62 to 60 W]). Time to exhaustion at FTP20 was 50.9±15.7 min. In conclusion, FTP20 and FTP60 should not be used interchangeably on an individual basis and their validity against IAT should be interpreted with caution.

Parameters of the 3-Minute All-Out Test: Overestimation of Competitive-Cyclist Time-Trial Performance in the Severe-Intensity Domain

2017 ◽  
Vol 12 (5) ◽  
pp. 655-661 ◽  
Author(s):  
Andrea Nicolò ◽  
Ilenia Bazzucchi ◽  
Massimo Sacchetti
Keyword(s):  
Power Output ◽  
Time Trial ◽  
Peak Power Output ◽  
Mean Power ◽  
Actual Performance ◽  
Predicting Performance ◽  
Significant Difference ◽  
Severe Intensity ◽  
Competitive Cyclists ◽  
Mean Power Output

Purpose:To verify the accuracy of predicting performance in the severe-intensity domain by means of end-test power output (EP) and the work performed above EP (WEP) obtained from a 3-min all-out test in competitive cyclists.Methods:Ten welltrained cyclists performed a ramp incremental test and a 3-min all-out familiarization test. Subsequently, they performed a 3-min all-out experimental test to obtain EP and WEP and a 10-min time trial (TT). The actual 10-min-TT mean power output was then compared with the power output predicted as P = WEP/Tlim + EP, where Tlim corresponds to 600 s. The ramp-test peak power output (PPO) was compared with PPO predicted as , where S represents the ramp slope (0.5 W/s).Results:The actual (347 ± 30 W) and predicted (376 ± 48 W) 10-min TT mean power output were correlated (r = .87, P = .001) but significantly different (P < .01). The coefficient of variation (CV) between the predicted and actual performance was 5.6% ± 4.4%. The error of prediction was positively correlated to EP (r = .80, P = .005) and negatively correlated to WEP (r = –.71, P = .021). No significant difference was found between the 10-min-TT mean power output and EP (351 ± 53 W). The actual (438 ± 30 W) and predicted (472 ± 41 W) ramp PPO were correlated (r = .88, P < .001) but significantly different (P < .001). The CV between the predicted and actual PPO was 5.2% ± 3%. The error of prediction was positively correlated to EP (r = .63, P = .051).Conclusions:EP and WEP obtained from a 3-min all-out test overestimate severe-intensity performance in competitive cyclists.

scholarly journals Re-esterified DHA improves ventilatory threshold 2 in competitive amateur cyclists

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Vicente Ávila-Gandía ◽  
Antonio Torregrosa-García ◽  
Antonio J. Luque-Rubia ◽  
María Salud Abellán-Ruiz ◽  
Desirée Victoria-Montesinos ◽  
...  
Keyword(s):  
Power Output ◽  
Ventilatory Threshold ◽  
Heart Rate Recovery ◽  
Recovery Phase ◽  
Lactate Clearance ◽  
Mean Power ◽  
Double Blind ◽  
Cycling Test ◽  
Competitive Cyclists ◽  
Mean Power Output

Abstract Background Fish oils were studied as ergogenic aids in a number of mixed physical trial designs showing promising results. However, the heterogeneous purity of the studied supplements, combined with the variety of physical tests employed call for more studies to confirm these findings, ideally with standardised supplements. Our aim was to test a supplement highly concentrated in DHA (DHA:EPA ratio equal to approximately 8:1) on a maximal cycling test to elucidate performance improvements mainly due to DHA. Methods A double-blind, placebo controlled, randomised balanced, parallel design, in competitive amateur cyclists was employed. They were all male, older than 18 years old, with training routine of 2 to 4 sessions per week lasting at least one hour each. A ramp cycling test to exhaustion with a subsequent 5 min recovery phase was employed before and after treatment to analyse aerobic metabolism and lactate clearance after the bout. After 30 days of supplementation with 975 mg of re-esterified DHA, the thirty-eight cyclist who completed the study were finally included for statistical analysis. Results Mean power output at ventilatory threshold 2 (VT2) improved after DHA supplementation both as absolute (△DHA versus △PLA: 6.33–26.54 Watts; CI 95%) and relative (p=0.006) values, paralleled with higher oxygen consumption at VT2 both for absolute (DHA 2729.4 ±304.5, 3045.9 ±335.0; PLA 2792.3 ±339.5, 2845.5 ±357.1; ml·min−1 baseline versus post p=0.025) and relative values (DHA 36.6 ±5.0, 41.2 ±5.4; PLA 37.2 ±5.7, 38.1 ±5.2; ml·kg−1·min−1 baseline versus post p=0.024). Heart rate recovery rate improved during the recovery phase in the DHA group compared to PLA (p=0.005). Conclusion DHA is capable of improving mean power output at the ventilatory threshold 2 (anaerobic ventilatory threshold) in amateur competitive cyclists. It is unclear if these findings are the result of the specific DHA supplement blend or another factor.

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.

Acute Beetroot Juice Supplementation Does Not Improve Cycling Performance in Normoxia or Moderate Hypoxia

2015 ◽  
Vol 25 (4) ◽  
pp. 359-366 ◽  
Author(s):  
Kristin E. MacLeod ◽  
Sean F. Nugent ◽  
Susan I. Barr ◽  
Michael S. Koehle ◽  
Benjamin C. Sporer ◽  
...  
Keyword(s):  
Steady State ◽  
Power Output ◽  
Time Trial ◽  
Small Sample ◽  
Oxygen Cost ◽  
Beetroot Juice ◽  
Mean Power ◽  
Double Blind ◽  
Moderate Hypoxia ◽  
Mean Power Output

Beetroot juice (BR) has been shown to lower the oxygen cost of exercise in normoxia and may have similar effects in hypoxia. We investigated the effect of BR on steady-state exercise economy and 10-km time trial (TT) performance in normoxia and moderate hypoxia (simulated altitude: ~2500 m). Eleven trained male cyclists (VO2peak ≥ 60 ml·kg-1·min-1) completed four exercise trials. Two hours before exercise, subjects consumed 70 mL BR (~6 mmol nitrate) or placebo (nitrate-depleted BR) in a randomized, double-blind manner. Subjects then completed a 15-min self-selected cycling warm-up, a 15-min steady-state exercise bout at 50% maximum power output, and a 10-km time trial (TT) in either normoxia or hypoxia. Environmental conditions were randomized and single-blind. BR supplementation increased plasma nitrate concentration and fraction of exhaled nitric oxide relative to PL (p < .05 for both comparisons). Economy at 50% power output was similar in hypoxic and normoxic conditions (p > .05), but mean power output was greater in the normoxic TT relative to the hypoxic TT (p < .05). BR did not affect economy, steady-state SpO2, mean power output, or 10-km TT completion time relative to placebo in either normoxia or hypoxia (p > .05 in all comparisons). In conclusion, BR did not lower the oxygen cost of steady-state exercise or improve exercise performance in normoxia or hypoxia in a small sample of well-trained male cyclists.

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.

Physiological Profile of an Uphill Time Trial in Elite Cyclists

2018 ◽  
Vol 13 (3) ◽  
pp. 268-273 ◽  
Author(s):  
Ana B. Peinado ◽  
Nuria Romero-Parra ◽  
Miguel A. Rojo-Tirado ◽  
Rocío Cupeiro ◽  
Javier Butragueño ◽  
...  
Keyword(s):  
Power Output ◽  
Perceived Exertion ◽  
Lactate Concentration ◽  
Time Trial ◽  
Cycling Performance ◽  
Mean Power ◽  
Road Cycling ◽  
And Performance ◽  
Mean Power Output ◽  
Elite Cyclists

Context: While a number of studies have researched road-cycling performance, few have attempted to investigate the physiological response in field conditions. Purpose: To describe the physiological and performance profile of an uphill time trial (TT) frequently used in cycling competitions. Methods: Fourteen elite road cyclists (mean ± SD age 25 ± 6 y, height 174 ± 4.2 cm, body mass 64.4 ± 6.1 kg, fat mass 7.48% ± 2.82%) performed a graded exercise test to exhaustion to determine maximal parameters. They then completed a field-based uphill TT in a 9.2-km first-category mountain pass with a 7.1% slope. Oxygen uptake (VO2), power output, heart rate (HR), lactate concentration, and perceived-exertion variables were measured throughout the field-based test. Results: During the uphill TT, mean power output and velocity were 302 ± 7 W (4.2 ± 0.1 W/kg) and 18.7 ± 1.6 km/h, respectively. Mean VO2 and HR were 61.6 ± 2.0 mL · kg−1 · min−1 and 178 ± 2 beats/min, respectively. Values were significantly affected by the 1st, 2nd, 6th, and final kilometers (P < .05). Lactate concentration and perceived exertion were 10.87 ± 1.12 mmol/L and 19.1 ± 0.1, respectively, at the end of the test, being significantly different from baseline measures. Conclusion: The studied uphill TT is performed at 90% of maximum HR and VO2 and 70% of maximum power output. To the authors’ knowledge, this is the first study assessing cardiorespiratory parameters combined with measures of performance, perceived exertion, and biochemical variables during a field-based uphill TT in elite cyclists.

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.

scholarly journals The Influence of Elliptical Chainrings on 10 km Cycling Time Trial Performance

2010 ◽  
Vol 5 (4) ◽  
pp. 459-468 ◽  
Author(s):  
Jeremiah J. Peiffer ◽  
Chris R. Abbiss
Keyword(s):  
Heart Rate ◽  
Power Output ◽  
Time Trial ◽  
Total Power ◽  
Mean Power ◽  
Actual Performance ◽  
Cycling Time Trial ◽  
And Performance ◽  
Mean Power Output ◽  
Cycling Time

The use of elliptical chainrings (also called chainwheels or sprockets) has gained considerable interest in the amateur and professional cycling community. Nevertheless, we are unaware of any scientific studies that have examined the performance benefits of using elliptical chainrings during an actual performance trial. Therefore, this study examined the influence of elliptical chainring use on physiological and performance parameters during a 10 km cycling time trial. Nine male cyclists completed, in a counterbalanced order, three 10 km cycling time trials using either a standard chainring or an elliptical chainring at two distinct settings. An attempt was made to blind the cyclists to the type of chainring used until the completion of the study. During the 10 km time trial, power output and heart rate were recorded at a frequency of 1 Hz and RPE was measured at 3, 6, and 8.5 km. Total power output was not different (P = .40) between the circular (340 ± 30 W) or either elliptical chainring condition (342 ± 29 W and 341 ± 31 W). Similarly, no differences (P = .73) in 2 km mean power output were observed between conditions. Further, no differences in RPE were observed between conditions measured at 3, 6, and 8.5 km. Heart rate was significantly greater (P = .02) using the less aggressive elliptical setting (174 ± 10 bpm) compared with the circular setting (171 ± 9 bpm). Elliptical chainrings do not appear to provide a performance benefit over traditional circular chainrings during a mid-distance time trial.

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.

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