scholarly journals Caffeine and Sprint Cycling Performance: Effects of Torque Factor and Sprint Duration

2019 ◽  
Vol 14 (4) ◽  
pp. 426-431
Author(s):  
Mark Glaister ◽  
Colin Towey ◽  
Owen Jeffries ◽  
Daniel Muniz-Pumares ◽  
Paul Foley ◽  
...  
Keyword(s):  
Peak Power ◽  
Cycling Performance ◽  
Mean Difference ◽  
Peak Power Output ◽  
Double Blind ◽  
Double Blind Placebo ◽  
Performance Effects ◽  
Sprint Cycling ◽  
Post Hoc ◽  
Sprint Duration

Purpose:To investigate the influence of torque factor and sprint duration on the effects of caffeine on sprint cycling performance.Methods:Using a counterbalanced, randomized, double-blind, placebo-controlled design, 13 men completed 9 trials. In trial 1, participants completed a series of 6-s sprints at increasing torque factors to determine the torque factor, for each individual, that elicited the highest (Toptimal) peak power output (PPO). The remaining trials involved all combinations of torque factor (0.8 N·m−1·kg−1vsToptimal), sprint duration (10 s vs 30 s), and supplementation (caffeine [5 mg·kg−1] vs placebo).Results:There was a significant effect of torque factor on PPO, with higher values atToptimal(mean difference 168 W; 95% likely range 142–195 W). There was also a significant effect of sprint duration on PPO, with higher values in 10-s sprints (mean difference 52 W; 95% likely range 18–86 W). However, there was no effect of supplementation on PPO (P = .056). Nevertheless, there was a significant torque factor × sprint duration × supplement interaction (P = .036), with post hoc tests revealing that caffeine produced a higher PPO (mean difference 76 W; 95% likely range 19–133 W) when the sprint duration was 10 s and the torque factor wasToptimal.Conclusion:The results of this study show that when torque factor and sprint duration are optimized, to allow participants to express their highest PPO, there is a clear effect of caffeine on sprinting performance.

Endurance, aerobic high-intensity, and repeated sprint cycling performance is unaffected by normobaric “Live High-Train Low”: a double-blind placebo-controlled cross-over study

2017 ◽  
Vol 117 (5) ◽  
pp. 979-988 ◽  
Author(s):  
Jacob Bejder ◽  
Andreas Breenfeldt Andersen ◽  
Rie Buchardt ◽  
Tanja Hultengren Larsson ◽  
Niels Vidiendal Olsen ◽  
...  
Keyword(s):  
High Intensity ◽  
Cycling Performance ◽  
Double Blind ◽  
Double Blind Placebo ◽  
Repeated Sprint ◽  
Sprint Cycling

scholarly journals Isovelocity vs. Isoinertial Sprint Cycling Tests for Power- and Torque-cadence Relationships

2019 ◽  
Vol 40 (14) ◽  
pp. 897-902 ◽  
Author(s):  
Mehdi Kordi ◽  
Jonathan Folland ◽  
Stuart Goodall ◽  
Paul Barratt ◽  
Glyn Howatson
Keyword(s):  
Performance Measures ◽  
Power Output ◽  
Peak Power ◽  
Cycling Performance ◽  
Peak Power Output ◽  
Maximum Torque ◽  
Functional Measures ◽  
Sprint Cycling ◽  
Optimal Cadence

AbstractSprint cycling performance is heavily dependent on mechanical peak power output (PPO) and the underlying power- and torque-cadence relationships. Other key indices of these relationships include maximum torque (TMAX), cadence (CMAX) and optimal cadence (COPT). Two common methods are used in the laboratory to ascertain PPO: isovelocity and isoinertial. Little research has been carried out to compare the magnitude and reliability of these performance measures with these two common sprint cycling assessments. The aim of this study was to compare the magnitude and reliability of PPO, TMAX, CMAX and COPT measured with isovelocity and isoinertial sprint cycling methods. Two experimental sessions required 20 trained cyclists to perform isoinertial sprints and then isovelocity sprints. For each method, power-cadence and torque-cadence relationships were established, and PPO and COPT were interpolated and TMAX and CMAX were extrapolated. The isoinertial method produced significantly higher PPO (p<0.001) and TMAX (p<0.001) than the isovelocity method. However, the isovelocity method produced significantly higher COPT (p<0.001) and CMAX (p=0.002). Both sprint cycling tests showed high levels of between-session reliability (isoinertial 2.9–4.4%; isovelocity 2.7–4.0%). Functional measures of isovelocity and isoinertial sprint cycling tests were highly reliable but should not be used interchangably.

Dietary Antioxidant Supplementation Combined with Quercetin Improves Cycling Time Trial Performance

2006 ◽  
Vol 16 (4) ◽  
pp. 405-419 ◽  
Author(s):  
Holden S-H. MacRae ◽  
Kari M. Mefferd
Keyword(s):  
Peak Power ◽  
Time Trial ◽  
Cycling Performance ◽  
Antioxidant Supplementation ◽  
Double Blind ◽  
Cycling Time Trial ◽  
Dietary Antioxidant ◽  
Power Peak ◽  
Manova Analysis ◽  
Trial Performance

We investigated whether 6 wk of antioxidant supplementation (AS) would enhance 30 km time trial (TT) cycling performance. Eleven elite male cyclists completed a randomized, double-blind, cross-over study to test the effects of twice daily AS containing essential vitamins plus quercetin (FRS), and AS minus quercetin (FRS-Q) versus a baseline TT (B). MANOVA analysis showed that time to complete the 30 km TT was improved by 3.1% on FRS compared to B (P ≤ 0.01), and by 2% over the last 5 km (P ≤ 0.05). Absolute and relative (%HRmax) heart rates and percent VO2max were not different between trials, but average and relative power (% peak power) was higher on FRS (P ≤ 0.01). Rates of carbohydrate and fat oxidation were not different between trials. Thus, FRS supplementation significantly improved high-intensity cycling TT performance through enhancement of power output. Further study is needed to determine the potential mechanism(s) of the antioxidant efficacy.

Lithium vs valproate in the maintenance treatment of bipolar I disorder: A post- hoc analysis of a randomized double-blind placebo-controlled trial

2019 ◽  
Vol 54 (3) ◽  
pp. 298-307
Author(s):  
Mehar G Kang ◽  
Hong Qian ◽  
Kamyar Keramatian ◽  
Trisha Chakrabarty ◽  
Gayatri Saraf ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Atypical Antipsychotic ◽  
Maintenance Treatment ◽  
Atypical Antipsychotics ◽  
Controlled Trial ◽  
Hazard Ratio ◽  
Double Blind ◽  
Double Blind Placebo ◽  
Post Hoc Analysis ◽  
Post Hoc

Objective: Lithium and valproate are commonly used either in monotherapy or in combination with atypical antipsychotics in maintenance treatment of bipolar I disorder; however, their comparative efficacy is not well understood. This study aimed to compare the efficacy of valproate and lithium on mood stability either in monotherapy or in combination with atypical antipsychotics. Methods: We performed a post hoc analysis using data from a 52-week randomized double-blind, placebo-controlled trial, that recruited 159 patients with recently remitted mania during treatment with lithium or valproate and adjunctive atypical antipsychotic therapy. Patients were randomized to discontinue adjunctive atypical antipsychotic at 0, 24 or 52 weeks. Results: No significant differences in efficacy were observed between valproate and lithium (hazard ratio: 0.99; 95% confidence interval: [0.66, 1.48]) in time to any mood event. Valproate with 24 weeks of atypical antipsychotic was significantly superior to valproate monotherapy in preventing any mood relapse (hazard ratio: 0.46; 95% confidence interval: [0.22, 0.97]) while lithium with 24 weeks of atypical antipsychotic was superior to lithium monotherapy in preventing mania (hazard ratio: 0.27; 95% confidence interval: [0.09, 0.85]) but not depression. Conclusion: Overall, this study did not find significant differences in efficacy between the two mood-stabilizing agents when used as monotherapy or in combination with atypical antipsychotics. However, study design and small sample size might have precluded from detecting an effect if true difference in efficacy existed. Further head-to-head investigations with stratified designs are needed to evaluate maintenance therapies.

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