scholarly journals Relationship Between the Critical Power Test and a 20-min Functional Threshold Power Test in Cycling

2021 ◽  
Vol 11 ◽  
Author(s):  
Bettina Karsten ◽  
Luca Petrigna ◽  
Andreas Klose ◽  
Antonino Bianco ◽  
Nathan Townsend ◽  
...  
Keyword(s):  
Critical Power ◽  
Pearson Correlation ◽  
Time Trial ◽  
Peak Oxygen Consumption ◽  
Threshold Power ◽  
Strong Correlations ◽  
Mean Power ◽  
Power Test ◽  
Paired Samples ◽  
The Mean

To investigate the agreement between critical power (CP) and functional threshold power (FTP), 17 trained cyclists and triathletes (mean ± SD: age 31 ± 9 years, body mass 80 ± 10 kg, maximal aerobic power 350 ± 56 W, peak oxygen consumption 51 ± 10 mL⋅min–1⋅kg–1) performed a maximal incremental ramp test, a single-visit CP test and a 20-min time trial (TT) test in randomized order on three different days. CP was determined using a time-trial (TT) protocol of three durations (12, 7, and 3 min) interspersed by 30 min passive rest. FTP was calculated as 95% of 20-min mean power achieved during the TT. Differences between means were examined using magnitude-based inferences and a paired-samples t-test. Effect sizes are reported as Cohen’s d. Agreement between CP and FTP was assessed using the 95% limits of agreement (LoA) method and Pearson correlation coefficient. There was a 91.7% probability that CP (256 ± 50 W) was higher than FTP (249 ± 44 W). Indeed, CP was significantly higher compared to FTP (P = 0.041) which was associated with a trivial effect size (d = 0.04). The mean bias between CP and FTP was 7 ± 13 W and LoA were −19 to 33 W. Even though strong correlations exist between CP and FTP (r = 0.969; P < 0.001), the chance of meaningful differences in terms of performance (1% smallest worthwhile change), were greater than 90%. With relatively large ranges for LoA between variables, these values generally should not be used interchangeably. Caution should consequently be exercised when choosing between FTP and CP for the purposes of performance analysis.

scholarly journals Reliability of the Functional Threshold Power in Competitive Cyclists

2020 ◽  
Vol 41 (03) ◽  
pp. 175-181
Author(s):  
Fernando Klitzke Borszcz ◽  
Artur Ferreira Tramontin ◽  
Vitor Pereira Costa
Keyword(s):  
Intraclass Correlation ◽  
Time Trial ◽  
Threshold Power ◽  
Mean Power ◽  
Warm Up ◽  
Pacing Strategy ◽  
Trial Test ◽  
Competitive Cyclists ◽  
Change In The Mean ◽  
The Mean

AbstractFunctional threshold power (FTP) is defined as the highest power that a cyclist can maintain in a quasi-steady state without fatigue for approximately 1 hour. To improve practicality, a 20-minute time-trial test was proposed, where FTP is represented by 95% of the mean power produced. It is preceded by a specific 45-min warm-up, with periods of low intensity, fast accelerations, and a 5-min time-trial. Thus, the aim of this study was to determine the reliability of this protocol, including the reliability of the warm-up, pacing strategy, and FTP determination. For this purpose, 25 trained cyclists performed a familiarization and two other tests separated by seven days. The coefficient of variation (CV [%]), intraclass correlation coefficient (ICC), and change in the mean between test and retest were calculated. The results show that the 20-min time-trial was reliable (CV=2.9%, ICC=0.97), despite a less reliable warm-up (CV=5.5%, ICC=0.84). The changes in the mean between the test and retest were trivial to small for all measurements, and the pacing strategy was consistent across all trials. These results suggest that FTP determination with a 20-min protocol was reliable in trained cyclists.

The Reliability of 4-Minute and 20-Minute Time Trials and Their Relationships to Functional Threshold Power in Trained Cyclists

2019 ◽  
Vol 14 (1) ◽  
pp. 38-45 ◽  
Author(s):  
Martin J. MacInnis ◽  
Aaron C.Q. Thomas ◽  
Stuart M. Phillips
Keyword(s):  
Intraclass Correlation ◽  
Performance Testing ◽  
Time Trial ◽  
Cycling Performance ◽  
Threshold Power ◽  
Mean Power ◽  
Typical Error ◽  
The Mean ◽  
Mean Power Output ◽  
Elite Cyclists

Purpose: The mean power output (MPO) from a 60-min time trial (TT)—also known as functional threshold power, or FTP—is a standard measure of cycling performance; however, shorter performance tests are desirable to reduce the burden of performance testing. The authors sought to determine the reliability of 4- and 20-min TTs and the extent to which these short TTs were associated with 60-min MPO. Methods: Trained male cyclists (n = 8; age = 25 [5] y;  = 71 [5] mL/kg/min) performed two 4-min TTs, two 20-min TTs, and one 60-min TT. Critical power (CP) was estimated from 4- and 20-min TTs. The typical error of the mean (TEM) and intraclass correlation coefficient (ICC) were calculated to assess reliability, and R2 values were calculated to assess relationships with 60-min MPO. Results: Pairs of 4-min TTs (mean: 417 [SD: 45] W vs 412 [49] W, P = .25; TEM = 8.1 W; ICC = .98), 20-min TTs (342 [36] W vs 344 [33] W, P = .41; TEM = 4.6 W; ICC = .99), and CP estimates (323 [35] W vs 328 [32] W, P = .25; TEM = 6.5; ICC = .98) were reliable. The 4-min MPO (R2 = .95), 20-min MPO (R2 = .92), estimated CP (R2 = .82), and combination of the 4- and 20-min MPO (adjusted R2 = .98) were strongly associated with the 60-min MPO (309 [26] W). Conclusion: The 4- and 20-min TTs appear useful for assessing performance in trained, if not elite, cyclists.

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.

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 Validity of Functional Threshold Power and Maximal Oxygen Uptake for Cycling Performance in Moderately Trained Cyclists

Sports ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 217 ◽  
Author(s):  
Arne Sørensen ◽  
Tore Kristian Aune ◽  
Vegar Rangul ◽  
Terje Dalen
Keyword(s):  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Local Level ◽  
Cycling Performance ◽  
Threshold Power ◽  
Mountain Bike ◽  
Mean Power ◽  
Valid Test ◽  
The Mean ◽  
And Performance

Cycling is a popular sport, and evaluation of the validity of tests to predict performance in competitions is important for athletes and coaches. Similarity between performance in sprints in mass-start bike races and in the laboratory is found, but, to our knowledge, no studies have investigated the relationship between laboratory measurements of maximal oxygen uptake (VO2max) and functional threshold power (FTP) with performance in official mass-start competitions. The purpose of this study was to evaluate the validity of a 20 min FTP test and VO2max as predictors for performance in an official mountain bike competition. Eleven moderately trained male cyclists at a local level participated in this study (age: 43 ± 5.1 years; height: 183.4 ± 5.4 m; weight: 84.4 ± 8.7 kg; body mass index: 25.1 ± 2.1). All subjects performed a 20 min FTP test in the laboratory to measure the mean power. In addition, the subjects completed an incremental test to exhaustion to determine VO2max. These two laboratory tests were analyzed together with the results from a 47 km mass-start mountain bike race, with a total elevation of 851 m. A significant relationship was found between the mean relative power (W/kg) for the 20 min FTP test and performance time in the race (r = −0.74, P < 0.01). No significant correlation was found between VO2max and cycling performance for these subjects (r = −0.37). These findings indicate that a 20 min FTP test is a more valid test for prediction of performance in mass-start bike races than a VO2max test for moderately trained cyclists.

Field-Derived Power–Duration Variables to Predict Cycling Time-Trial Performance

2020 ◽  
Vol 15 (8) ◽  
pp. 1095-1102
Author(s):  
Alfred Nimmerichter ◽  
Bernhard Prinz ◽  
Matthias Gumpenberger ◽  
Sebastian Heider ◽  
Klaus Wirth
Keyword(s):  
Critical Power ◽  
Total Error ◽  
Probabilistic Approach ◽  
Time Trial ◽  
Cycling Performance ◽  
Strongly Correlated ◽  
Limits Of Agreement ◽  
Mean Power ◽  
Work Time ◽  
Cycling Time Trial

Purpose: To evaluate the predictive validity of critical power (CP) and the work above CP (W′) on cycling performance (mean power during a 20-min time trial; TT20). Methods: On 3 separate days, 10 male cyclists completed a TT20 and 3 CP and W′ prediction trials of 1, 4, and 10 min and 2, 7, and 12 min in field conditions. CP and W′ were modeled across combinations of these prediction trials with the hyperbolic, linear work/time, and linear power inverse-time (INV) models. The agreement and the uncertainty between the predicted and actual TT20 were assessed with 95% limits of agreement and a probabilistic approach, respectively. Results: Differences between the predicted and actual TT20 were “trivial” for most of the models if the 1-min trial was not included. Including the 1-min trial in the INV and linear work/time models “possibly” to “very likely” overestimated TT20. The INV model provided the smallest total error (ie, best individual fit; 6%) for all cyclists (305 [33] W; 19.6 [3.6] kJ). TT20 predicted from the best individual fit-derived CP, and W′ was strongly correlated with actual TT20 (317 [33] W; r = .975; P < .001). The bias and 95% limits of agreement were 4 (7) W (−11 to 19 W). Conclusions: Field-derived CP and W′ accurately predicted cycling performance in the field. The INV model was most accurate to predict TT20 (1.3% [2.4%]). Adding a 1-min-prediction trial resulted in large total errors, so it should not be included in the models.

Metabolic and neuromuscular responses at critical power from the 3-min all-out test

2013 ◽  
Vol 38 (1) ◽  
pp. 7-13 ◽  
Author(s):  
Haley C. Bergstrom ◽  
Terry J. Housh ◽  
Jorge M. Zuniga ◽  
Daniel A. Traylor ◽  
Robert W. Lewis ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Critical Power ◽  
Peak Oxygen Consumption ◽  
Common Mechanism ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Emg Amplitude ◽  
Production Ratio ◽  
Significant Difference ◽  
Neuromuscular Responses

The purpose of this study was to determine the specific metabolic and neuromuscular responses at critical power (CP) from the 3-min all-out test. Nine men (mean ± SD: aged 23.7 ± 3.3 years) performed an incremental test for the determination of peak oxygen consumption (V̇O2peak) and gas exchange threshold. CP was estimated for each subject from the 3-min all-out test. Oxygen consumption (V̇O2), the ventilation versus carbon dioxide production ratio (V̇E/V̇CO2 ratio), electromyographic (EMG) amplitude, and EMG mean power frequency (MPF) were examined during exhaustive rides at CP for each subject. There was no significant difference between the V̇O2 at exhaustion (40.6 ± 7.5 mL·kg−1·min−1) and V̇O2peak (42.9 ± 7.3 mL·kg−1·min−1). Furthermore, there were significant increases in EMG amplitude and the V̇E/V̇CO2 ratio during the exhaustive rides at CP. There was, however, no significant change in EMG MPF over time. Therefore, the current findings indicated that the 3-min all-out test overestimated CP and the demarcation between the heavy- and severe-intensity domains. Specifically, the V̇O2, ventilatory, and EMG amplitude responses were consistent with those observed during continuous exercise in the severe exercise intensity domain. It is likely that the ventilatory and EMG amplitude responses were associated with a common mechanism of fatigue that is different from what affects EMG MPF.

Cervical length at 31–34 weeks of gestation: transvaginal vs. transperineal ultrasonographic approach

2019 ◽  
Vol 47 (8) ◽  
pp. 817-821 ◽  
Author(s):  
Ioannis Tsakiridis ◽  
Themistoklis Dagklis ◽  
Apostolos Mamopoulos ◽  
Angeliki Gerede ◽  
Apostolos Athanasiadis
Keyword(s):  
Correlation Coefficient ◽  
Pearson Correlation ◽  
Close Correlation ◽  
Cervical Length ◽  
Tolerance Interval ◽  
Pearson Correlation Coefficient ◽  
Altman Plot ◽  
Bland Altman Plot ◽  
Paired Samples ◽  
The Mean

Abstract Objectives To investigate the correlation between transperineal (TP) and transvaginal (TV) ultrasonography in the measurement of cervical length (CL) in the third trimester of pregnancy. Methods In this prospective study, CL measurements were conducted in women between 31 and 34 weeks of gestation by both the TP and TV approaches. A comparison of the measurements was made between the two techniques. The Pearson correlation coefficient, the paired samples t-test and Bland-Altman plot were used. Results In total, 240 women participated in the study. The CL was successfully measured transvaginally in all cases and transperineally in 229 (95.4%) of the cases. The mean TV CL was 32.8 ± 8.2 mm and the mean TP CL was 32.5 ± 8.1 mm. In the 229 cases with paired measurements, the Pearson correlation coefficient was 0.964. No significant differences in mean CL were identified between the two methods (t = 1.805; P = 0.072). In the Bland-Altman plot, the difference between the paired means was 0.26 mm and the 95% tolerance interval for any given paired observation (TV CL–TP CL) was −4.05 to 4.57 mm. Conclusion The findings of this study suggest that at 31–34 weeks of gestation the cervix can be visualized adequately by both the TV and TP sonography in about 95% of cases. The TP CL measurements demonstrate a close correlation with the TV measurements. TP ultrasound is a feasible alternative, especially in cases where the use of the vaginal transducer should be minimized or is not acceptable by women.

A Comparison of Caffeine versus Pseudoephedrine on Cycling Time-Trial Performance

2013 ◽  
Vol 23 (5) ◽  
pp. 507-512 ◽  
Author(s):  
Angela L. Spence ◽  
Marc Sim ◽  
Grant Landers ◽  
Peter Peeling
Keyword(s):  
Time Trial ◽  
Mean Power ◽  
Cycling Time Trial ◽  
Familiarization Trial ◽  
Urinary Levels ◽  
The Mean ◽  
Experimental Trials ◽  
Cns Stimulant ◽  
Cycling Time ◽  
Trial Performance

Both caffeine (CAF) and pseudoephedrine (PSE) are proposed to be central nervous system stimulants. However, during competition, CAF is a permitted substance, whereas PSE is a banned substance at urinary levels >150 μg·ml−1. As a result, this study aimed to compare the effect of CAF versus PSE use on cycling time trial (TT) performance to explore whether the legal stimulant was any less ergogenic than the banned substance. Here, 10 well-trained male cyclists or triathletes were recruited for participation. All athletes were required to attend the laboratory on four separate occasions—including a familiarization trial and three experimental trials, which required participants to complete a simulated 40 km (1,200 kJ) cycling TT after the ingestion of either 200 mg CAF, 180 mg PSE or a nonnutritive placebo (PLA). The results showed that the total time taken and the mean power produced during each TT was not significantly different (p > .05) between trials, despite a 1.3% faster overall time (~57 s) after CAF consumption. Interestingly, the time taken to complete the second half of the TT was significantly faster (p < .05) in CAF as compared with PSE (by 99 s), with magnitude based inferences suggesting a 91% beneficial effect of CAF during the second half of the TT. This investigation further confirms the ergogenic benefits of CAF use during TT performances and further suggests this legal CNS stimulant has a better influence than a supra-therapeutic dose of PSE.

scholarly journals Digit ratio (2D:4D): relationship with freestyle swimming performance of adolescent well-trained swimmers

2019 ◽  
Vol 23 (3) ◽  
pp. 150-154
Author(s):  
G. Özen ◽  
Ö. Atar ◽  
H. Koç
Keyword(s):  
Body Mass ◽  
Swimming Performance ◽  
Pearson Correlation ◽  
Body Height ◽  
Ring Finger ◽  
Time Trial ◽  
Digit Ratio ◽  
Training Experience ◽  
Digit Ratios ◽  
The Mean

Purpose: The purpose of this study was to determine whether there was a relationship between the digit ratios and freestyle swimming performance of adolescent well-trained swimmers. Material and Methods: Twenty-two well-trained male swimmers who had at least 3 years of swim training experience were recruited as participants. The participants’ mean age was 14.1±1.5 years, body height was 164.5±11.3 cm, and body mass was 54.4±11.2 kg. Participants’ body height, mass, index finger (2D) and ring finger (4D) lengths were measured and digit ratio (2D:4D) and body mass index of participants was calculated. To determine the swimming performance of participants, the short (50m and 100m) and middle (200m and 400m) distance freestyle time-trial swimming tests were performed on participants. The association between the 2D:4D ratio and the swimming performance were determined by the Pearson correlation coefficient. Results. Our findings indicated that there were strong negative correlations (r > .50) between the mean of BMI and swimming times of adolescent swimmers. ( p > .05 ). However, result of this study revealed no relationship between the digit ratio (2D:4D) and swimming performance in adolescent swimmers. ( p > .05 ). Conclusion. As a result, it may be stated that the 2D:4D ratio of swimmers is not a major parameter in predicting swimming performance for adolescent swimmers.

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