scholarly journals Relationship Between Critical Power and Different Lactate Threshold Markers in Recreational Cyclists

2021 ◽  
Vol 12 ◽  
Author(s):  
Pedro L. Valenzuela ◽  
Lidia B. Alejo ◽  
Almudena Montalvo-Pérez ◽  
Jaime Gil-Cabrera ◽  
Eduardo Talavera ◽  
...  

Purpose: To analyze the relationship between critical power (CP) and different lactate threshold (LT2) markers in cyclists.Methods: Seventeen male recreational cyclists [33 ± 5 years, peak power output (PO) = 4.5 ± 0.7 W/kg] were included in the study. The PO associated with four different fixed (onset of blood lactate accumulation) and individualized (Dmaxexp, Dmaxpol, and LTΔ1) LT2 markers was determined during a maximal incremental cycling test, and CP was calculated from three trials of 1-, 5-, and 20-min duration. The relationship and agreement between each LT2 marker and CP were then analyzed.Results: Strong correlations (r = 0.81–0.98 for all markers) and trivial-to-small non-significant differences (Hedges’ g = 0.01–0.17, bias = 1–9 W, and p > 0.05) were found between all LT2 markers and CP with the exception of Dmaxexp, which showed the strongest correlation but was slightly higher than the CP (Hedges’ g = 0.43, bias = 20 W, and p < 0.001). Wide limits of agreement (LoA) were, however, found for all LT2 markers compared with CP (from ±22 W for Dmaxexp to ±52 W for Dmaxpol), and unclear to most likely practically meaningful differences (PO differences between markers >1%, albeit <5%) were found between markers attending to magnitude-based inferences.Conclusion: LT2 markers show a strong association and overall trivial-to-small differences with CP. Nevertheless, given the wide LoA and the likelihood of potentially meaningful differences between these endurance-related markers, caution should be employed when using them interchangeably.

2018 ◽  
Vol 13 (10) ◽  
pp. 1293-1298 ◽  
Author(s):  
Pedro L. Valenzuela ◽  
Javier S. Morales ◽  
Carl Foster ◽  
Alejandro Lucia ◽  
Pedro de la Villa

Purpose: To analyze the relationship between functional threshold power (FTP) and the lactate threshold (LT). Methods: A total of 20 male cyclists performed an incremental test in which LT was determined. At least 48 h later, they performed a 20-min time trial, and 95% of the mean power output was defined as FTP. Participants were divided into recreational (peak power output < 4.5 W·kg−1; n = 11) or trained cyclists (peak power output > 4.5 W·kg−1; n = 9) according to their fitness status. Results: The FTP (240 [35] W) was overall not significantly different (effect size = 0.20; limits of agreement = −2.4% [11.5%]) from the LT (246 [24] W), and both markers were strongly correlated (r = .95; P < .0001). Accounting for the participants’ fitness status, no significant differences were found between FTP and LT (effect size = 0.22; limits of agreement =2.1% [7.8%]) in trained cyclists, but FTP was significantly lower than the LT (P = .0004, effect size = 0.81; limits of agreement =−6.5% [8.3%]) in recreational cyclists. A significant relationship was found between relative peak power output and the bias between FTP and the LT markers (r = .77; P < .0001). Conclusions: FTP is a valid field test-based marker for the assessment of endurance fitness. However, caution should be taken when using FTP interchangeably with LT, as the bias between markers seems to depend on the athlete’s fitness status. Whereas FTP provides a good estimate of LT in trained cyclists, in recreational cyclists, it may underestimate LT.


2003 ◽  
Vol 35 (Supplement 1) ◽  
pp. S337
Author(s):  
D J. Bentley ◽  
L R. McNaughton ◽  
V E. Vleck ◽  
J Hatcher

2001 ◽  
Vol 33 (12) ◽  
pp. 2077-2081 ◽  
Author(s):  
DAVID J. BENTLEY ◽  
LARS R. MCNAUGHTON ◽  
DYLAN THOMPSON ◽  
VERONICA E. VLECK ◽  
ALAN M. BATTERHAM

2018 ◽  
Vol 64 (1) ◽  
pp. 137-146
Author(s):  
Jean-François Dionne ◽  
Claude Lajoie ◽  
Philippe Gendron ◽  
Eduardo Freiberger ◽  
François Trudeau

Abstract The purpose of our study was to assess physiological adaptations and measure mood outcomes following a cycling training camp in competitive athletes. Fourteen competitive athletes (8 males, 6 females) performed 2 incremental tests to exhaustion before and after a training camp. Volume and intensity (load) of the training regimen were recorded. Submaximal and maximal metabolic data were analysed, as well as economy variables (gross mechanical efficiency and cycling economy). Skeletal muscle adaptations were assessed using near infrared spectroscopy (NIRS). For both genders (n = 14), peak power output, peak power output-W/kg ratio and peak power output-B[La] were significantly increased (p < 0.05) after the cycling training camp (p < 0.05). Significant increases occurred for gross mechanical efficiency measured at the lactate threshold (+4.9%) and at the same precamp lactate threshold power output (+2.9%). At the lactate threshold and Post Camp Lactate Threshold Power, cycling economy increased by 5.2 and 2.9%, respectively (p < 0.05). These power measurements were significantly correlated with individual fluctuations in deoxyhaemoglobin in the vastus lateralis for male cyclists only. Profile of Mood State questionnaire results showed that subcategories “Tension-Anxiety”, “Confusion”, “Fatigue” and “Total Global Score” significantly decreased after the training camp. Cycling training camps were associated with positive adaptations (increased cycling economy, gross mechanical efficiency and power output) as well as some mental benefits. This indicates that despite some significant physiological adaptations participants probably did not overreach during their CTC.


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

Circulation ◽  
2021 ◽  
Vol 143 (Suppl_1) ◽  
Author(s):  
Colin Carriker ◽  
Phillip Armentrout ◽  
Sarah Levine ◽  
James Smoliga

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.


1996 ◽  
Vol 271 (2) ◽  
pp. C676-C683 ◽  
Author(s):  
J. J. Widrick ◽  
S. W. Trappe ◽  
D. L. Costill ◽  
R. H. Fitts

Gastrocnemius muscle fiber bundles were obtained by needle biopsy from five middle-aged sedentary men (SED group) and six age-matched endurance-trained master runners (RUN group). A single chemically permeabilized fiber segment was mounted between a force transducer and a position motor, subjected to a series of isotonic contractions at maximal Ca2+ activation (15 degrees C), and subsequently run on a 5% polyacrylamide gel to determine myosin heavy chain composition. The Hill equation was fit to the data obtained for each individual fiber (r2 > or = 0.98). For the SED group, fiber force-velocity parameters varied (P < 0.05) with fiber myosin heavy chain expression as follows: peak force, no differences: peak tension (force/fiber cross-sectional area), type IIx > type IIa > type I; maximal shortening velocity (Vmax, defined as y-intercept of force-velocity relationship), type IIx = type IIa > type I; a/Pzero (where a is a constant with dimensions of force and Pzero is peak isometric force), type IIx > type IIa > type I. Consequently, type IIx fibers produced twice as much peak power as type IIa fibers, whereas type IIa fibers produced about five times more peak power than type I fibers. RUN type I and IIa fibers were smaller in diameter and produced less peak force than SED type I and IIa fibers. The absolute peak power output of RUN type I and IIa fibers was 13 and 27% less, respectively, than peak power of similarly typed SED fibers. However, type I and IIa Vmax and a/Pzero were not different between the SED and RUN groups, and RUN type I and IIa power deficits disappeared after power was normalized for differences in fiber diameter. Thus the reduced absolute peak power output of the type I and IIa fibers from the master runners was a result of the smaller diameter of these fibers and a corresponding reduction in their peak isometric force production. This impairment in absolute peak power production at the single fiber level may be in part responsible for the reduced in vivo power output previously observed for endurance-trained athletes.


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